RMH
56.7K views | +101 today
Follow
 
Scooped by mhryu@live.com
onto RMH
October 17, 2023 11:19 AM
Scoop.it!

Green leaf volatile sensory calcium transduction in Arabidopsis | NComm

Green leaf volatile sensory calcium transduction in Arabidopsis | NComm | RMH | Scoop.it

Plants perceive volatile organic compounds (VOCs) released by mechanically- or herbivore-damaged neighboring plants and induce various defense responses. Such interplant communication protects plants from environmental threats. However, the spatiotemporal dynamics of VOC sensory transduction in plants remain largely unknown. Using a wide-field real-time imaging method, we visualize an increase in cytosolic Ca2+ concentration ([Ca2+]cyt) in Arabidopsis leaves following exposure to VOCs emitted by injured plants. We identify two green leaf volatiles (GLVs), (Z)-3-hexenal (Z-3-HAL) and (E)-2-hexenal (E-2-HAL), which increase [Ca2+]cyt in Arabidopsis. These volatiles trigger the expression of biotic and abiotic stress-responsive genes in a Ca2+-dependent manner. Tissue-specific high-resolution Ca2+ imaging and stomatal mutant analysis reveal that [Ca2+]cyt increases instantly in guard cells and subsequently in mesophyll cells upon Z-3-HAL exposure. These results suggest that GLVs in the atmosphere are rapidly taken up by the inner tissues via stomata, leading to [Ca2+]cyt increases and subsequent defense responses in Arabidopsis leaves. Plants sense volatiles emitted by injured neighboring plants and elicit defense responses to external threats. Here, the authors show that Arabidopsis leaves uptake two green leaf volatiles via stomata and trigger cytosolic Ca2+ defense signaling.

mhryu@live.com's insight:

Using transgenic Arabidopsis expressing the Ca2+ biosensor GCaMP331, we observed [Ca2+]cyt changes in intact plants following exposure to VOCs emitted by damaged plants in real time.

No comment yet.
RMH
Your new post is loading...
Scooped by mhryu@live.com
Today, 2:58 PM
Scoop.it!

Balancing mutualism: choice and sanctions in root–microbe symbioses | nphy

Balancing mutualism: choice and sanctions in root–microbe symbioses | nphy | RMH | Scoop.it

Plant roots form symbioses with beneficial microorganisms to enhance nutrient acquisition. Most terrestrial plants form arbuscular mycorrhizal symbiosis (AMS) with obligate biotrophic Glomeromycotina fungi, which supply hosts with mineral nutrients in exchange for carbon through specialized symbiotic hyphal structures (arbuscules) that develop within root cortex cells. Legumes form root nodule symbiosis (RNS) with nitrogen-fixing rhizobia, which are housed as differentiated bacteroids within specialized symbiotic organs (nodules) and provide plants with ammonia in return for carbon. RNS exhibits high partner specificity, occurring only between compatible hosts and microbes. Conversely, AMS is less specific, although symbiosis outcomes are context-dependent and influenced by host and fungal genotype, environmental conditions, and microbial competition. In both cases, plants favor high-performing microsymbionts by recognizing them during symbiosis initiation or by punishing low-performing symbionts through postcolonization sanctions. Microbes, in turn, employ strategies to manipulate plants for their own benefit. Here, we review the molecular mechanisms underlying partner preference in beneficial plant–microbe interactions and discuss how host partner selection strategies maintain mutualistic stability in AMS and RNS, alongside microbial strategies to evade host control. Understanding the dynamic interplay of functionally diverse plant–microbe symbioses provides a basis for improving mutualisms in both natural and agricultural systems.

mhryu@live.com's insight:

2st

No comment yet.
Scooped by mhryu@live.com
Today, 2:00 PM
Scoop.it!

A comprehensive computational analysis investigating the relationships between phage codon usage, infection style, and number of tRNA genes | brvsys

It has been known for decades that bacteriophages encode tRNA genes, but their function and the factors contributing to their acquisition and retention are unclear. Although tRNAs are found in a variety of phages infecting a variety of bacteria, many large-scale computational studies investigating tRNA acquisition and retention in phages are specific to Mycobacterium phages; however, these findings may not be representative of other phages or bacteria. This work uses a broader sampling of phages and hosts to investigate the relationships between codon usage bias, infection cycle, and tRNA gene numbers in phage genomes. We analyzed 154 phages infecting 7 host genera, including Gram-negative (Escherichia, Shigella, Salmonella) and Gram-positive (Bacillus, Lactobacillus, Staphylococcus, Mycobacterium) bacteria. Phages included temperate and virulent representatives, plus a range of tRNA numbers and morphologies. All phages and hosts were analyzed using four metrics: GC content, Effective Number of Codons, Relative Synonymous Codon Usage, and tRNA Adaptation Index. On a global scale, virulent phages with many tRNA genes show greater differences in codon usage and codon adaptation compared to their respective hosts. Gram-negative bacteria and their phages generally exhibit greater differences in codon usage compared to Gram-positive bacteria and their phages. Phages infecting Gram-negative hosts also tend to encode more tRNA genes. In nearly all genus-level comparisons, Mycobacterium phages were different from any other host and from global patterns. This suggests previous computational studies performed in Mycobacterium phages are likely not applicable on a global scale or to phages infecting other host genera.

No comment yet.
Scooped by mhryu@live.com
Today, 1:13 PM
Scoop.it!

The limits of information in precise regulation of early multicellular life cycles | brve

The limits of information in precise regulation of early multicellular life cycles | brve | RMH | Scoop.it

A key step in the evolution of complex multicellularity is the emergence of regulated life cycles that coordinate growth and reproduction. One potential route toward regulation involves co-opting intrinsic information: cues generated by routine cellular activities such as aging or mechanical stress from growth. Here, we model the simplest form of multicellular organization, linear filaments, to investigate whether intrinsic information can be harnessed to produce regular multicellular life cycles. Based on our analyses, we find that these information sources face an inherent trade-off between flexibility and regularity. Some sources, such as mechanical stress, precisely regulate when reproduction occurs but generate only a single reproductive mode. Others, such as cell age, can in principle produce diverse life cycles but fail to generate any of them reliably. Combining information sources through simple genetic circuits reduces variance in some cases, but the range of achievable life cycles remains constrained. Together these results suggest that while intrinsic information may facilitate early multicellular evolution, there are significant limitations on the degree to which it can be harnessed to evolve tightly-regulated, flexible life cycles. Our work highlights the constraints faced by nascent multicellular organisms and the evolutionary innovations likely required for coordinated multicellular development.

mhryu@live.com's insight:

ratcliff, one-dimensional multicellular filaments, much like cyanobacteria

No comment yet.
Scooped by mhryu@live.com
Today, 12:56 PM
Scoop.it!

Designing mRNA coding sequence via multimodal reverse translation language modeling with Pro2RNA | brvai

Designing mRNA coding sequence via multimodal reverse translation language modeling with Pro2RNA | brvai | RMH | Scoop.it

mRNA coding sequence design is a critical component in the development of mRNA vaccines, nucleic acid therapeutics, and heterologous gene expression systems. While large language models have recently been successfully applied to protein design and RNA modeling, designing optimal mRNA coding sequences for a given protein, particularly in a species-specific manner, remains a major challenge. Here, we present Pro2RNA, a multimodal reverse-translation language model that generates mRNA coding sequences from their corresponding protein sequences while explicitly conditioning on host organism taxonomy information. Pro2RNA integrates multiple pretrained language models across different modalities, including ESM2 for protein representation, SciBERT for taxonomy understanding, and a generative RNA language model for mRNA codon-level sequence generation. By training on mRNA-protein pairs from eukaryote and bacteria datasets respectively, Pro2RNA learns species-dependent genetic codes and codon usage patterns, enabling the generation of host-adapted and natural-like mRNA coding sequences. Across multiple benchmark evaluations, Pro2RNA matches or surpasses existing optimization methods, demonstrating its potential as a powerful and flexible framework for species-aware mRNA coding sequence design.

mhryu@live.com's insight:

codon optimization

No comment yet.
Scooped by mhryu@live.com
Today, 12:48 PM
Scoop.it!

Bacteriophage host prediction using a genome language model | brvai

Bacteriophage host prediction using a genome language model | brvai | RMH | Scoop.it

Computational bacteriophage host prediction from genomic sequences remains challenging because host range depends on diverse, rapidly evolving genomic determinants—from receptor-binding proteins to anti-defense systems and downstream infection compatibility—and because the signals available to predictors, including sequence homology, CRISPR spacer matches, nucleotide composition, and mobile genetic elements, are sparse, unevenly distributed across taxa, and constrained by incomplete host annotations. Here, we frame host prediction as an unsupervised retrieval problem. We asked whether embeddings from the pretrained genome language model Evo2 captured a reliable host-range signal without training on phage–host labels. We generated whole-genome embeddings for phages and candidate bacterial hosts with the Evo2-7B model, applied normalization, and ranked hosts by cosine similarity. Using the Virus-Host Database, we selected embedding and fusion choices on a Gram-positive validation cohort and then evaluated the approach on a held-out Gram-negative test cohort to minimize data leakage. We found that Evo2 was strongest at retrieving multiple plausible hosts, with the recorded host in the top 10 for 55.4% of phages. However, it did not maximize species-level top-1 accuracy (19.4% vs. 23.2% for the best baseline). At higher taxonomic ranks, Evo2 captured a coarser host-range signal: top-1 accuracy reached 43.4% at the genus level and 51.6% at the family level. Reciprocal rank fusion of Evo2 with BLASTN, VirHostMatcher, and PHIST improved all retrieval metrics. Top-10 retrieval rose to 58.5% and top-1 accuracy to 26.9%. Stratified analyses by phage genome length, host clade, and host mobile genetic element coverage revealed scenario-dependent performance. Evo2 embeddings excelled for intermediate-length phages and when host mobile element content was low, whereas alignment and k-mer methods dominated when local homology was abundant. These results suggest that pretrained genome embeddings complement established alignment- and k-mer/composition-based methods and that context-aware hybrid pipelines may help improve phage host prediction.

No comment yet.
Scooped by mhryu@live.com
Today, 12:34 PM
Scoop.it!

Evaluating codon optimization strategies for mammalian glycoprotein production with an open-source expression vector | brvbe

Evaluating codon optimization strategies for mammalian glycoprotein production with an open-source expression vector | brvbe | RMH | Scoop.it

Efficient production of human proteins for the development of tool compounds and biologics depends on a detailed understanding of the protein expression machinery in mammalian cells. Codon optimization is widely believed to enhance protein yield, yet its impact in homologous mammalian systems remains poorly defined. Here, we systematically compare five codon usage strategies reflecting common assumptions about rare codons, RNA stability, and synthesis efficiency. We developed pTipi, an efficient open source mammalian expression vector, and evaluated its performance in antibody production. We generated plasmids for common epitope tag antibodies such as V5, anti-biotin and anti-His for distribution by Addgene. To compare codon usage schemes, we performed a bake-off of 18 human and murine Wnt pathway glycoproteins in mammalian cells. Small-scale expression screens revealed that codon optimization does not provide a general advantage over native coding sequences, while strategies prioritizing RNA stability consistently reduced expression. Interestingly, a skewed codon scheme using the most abundant codons produced yields comparable to native sequences and occasionally enhanced protein output. To enable flexible evaluation of codon strategies, we implemented a Golden Gate compatible pTipi platform for efficient synthetic gene incorporation. We conclude that native codons are sufficient for robust homologous mammalian expression of glycoproteins, while selective codon skewing can be beneficial for some targets. 

No comment yet.
Scooped by mhryu@live.com
Today, 12:11 PM
Scoop.it!

Coordination of Cyanobacterial Nitrate Assimilation and Photosynthesis by a Novel PsbO-Interacting Protein PirN | advS

Coordination of Cyanobacterial Nitrate Assimilation and Photosynthesis by a Novel PsbO-Interacting Protein PirN | advS | RMH | Scoop.it

Nitrogen assimilation relies on photosynthetically produced energy and reducing equivalents. Here, we identify a small protein, PsbO-interacting regulator of nitrate assimilation (PirN), as a key coordinator of photosynthesis and nitrate assimilation in Synechocystis sp. PCC 6803. PirN specifically accumulates in nitrate-grown cells and interacts with the photosystem II (PSII) subunit PsbO. Deletion of pirN pirN) under nitrate impairs growth, reduces PSII contents and oxygen evolution, and upregulates most nitrogen transport and assimilation proteins except the nitrate reductase NarB, mimicking nitrogen starvation response likely due to impaired nitrate reduction. PsbO expression is markedly reduced in both ΔpirN and ΔnarB mutants. Complementation of narB or psbO in the ΔpirN mutant background largely rescued the growth defect of the mutant and led to increased expression of PsbO or NarB, respectively. These findings suggest that PirN is a nitrate-inducible regulator that hierarchically modulates NarB and PsbO expression to couple nitrate assimilation with photosynthetic activity. This coordination likely safeguards redox homeostasis when nitrate assimilation or photosynthetic electron production is perturbed.

No comment yet.
Scooped by mhryu@live.com
Today, 11:57 AM
Scoop.it!

Research progress and applications of gene activation editing technology in crops | frn

Research progress and applications of gene activation editing technology in crops | frn | RMH | Scoop.it

In recent years, CRISPR/Cas gene editing technology has become a fundamental method in biological breeding. As a vital tool for overcoming technological obstacles, it is currently widely used in functional gene research and genetic enhancement across a variety of organisms. Currently, CRISPR activation (CRISPRa) technology based on dCas9 fusion transcription activation domains has emerged as a powerful tool for expanding the application of CRISPR/Cas systems in improving traits in plants, animals, and microorganisms. This overview starts by going over the underlying principles and components of gene activation editing technology, as well as the phases of development of its three generations. It summarises the present difficulties and potential directions in this field while concentrating on the use of gene activation editing in important crop traits including growth and development regulation, stress resistance, and quality regulation. The objective is to offer valuable insights for the research and development of crop breeding.

No comment yet.
Scooped by mhryu@live.com
March 20, 1:47 AM
Scoop.it!

Next-generation proximity labeling: redefining protein interactomes | Tin

Next-generation proximity labeling: redefining protein interactomes | Tin | RMH | Scoop.it
Protein–protein interactions (PPIs) are fundamental to cellular function and metabolic regulation. Mapping these complex molecular networks is essential for understanding signaling pathways, yet it remains challenging due to their transient nature. We discuss how next-generation proximity labeling is evolving from bulk methods toward precise, dynamic PPI mapping, providing actionable biological insights.
mhryu@live.com's insight:

By fusing a promiscuous biotin ligase (e.g., TurboID) to a protein of interest

(A) Schematic of biotin-based proximity labeling (PL) for studying PPIs. Multiple bait proteins can be fused to split enzymes (i.e., n-enzyme and c-enzyme). Upon supplying biotin, the enzyme catalyzes the conversion to a reactive species that diffuses and covalently modifies lysine residues on neighboring interactors. Biotinylated protein interactors are then captured using streptavidin beads and identified by mass spectrometry (MS). (B) Schematic of CRISPR-driven PL for studying protein–DNA interactions. A labeling enzyme is fused to a catalytically inactive dCas9 protein and directed to a selected genomic region of interest. Upon addition of biotin, the enzyme generates reactive molecules that diffuse and covalently ‘tag’ nearby proteins at lysine residues. Biotinylated proteins can be purified by streptavidin beads and followed by MS identification. (C) Schematic of CRISPR-driven PL for studying protein–RNA interactions. The PL enzyme–dCas9 fusion is directed to a target RNA. Upon addition of biotin, the enzyme generates reactive species that covalently label neighboring proteins, which are then isolated via streptavidin pulldown and identified by MS. (D) MS-based four-dimensional analysis of protein interactors. Digested peptides from PL strategies can be subjected to 4D interactomic analysis. Advanced MS enables multidimensional profiling of protein interactions, including abundance, subcellular localization, turnover rates, and phosphorylation stoichiometry. The resulting interactome data are processed and analyzed using bioinformatic tools.

No comment yet.
Scooped by mhryu@live.com
March 20, 1:27 AM
Scoop.it!

Programmable genome editing in human cells using RNA-guided bridge recombinases | sci

Programmable genome editing in human cells using RNA-guided bridge recombinases | sci | RMH | Scoop.it
Site-specific insertion of gene-sized DNA fragments remains an unmet need in the field of genome editing. IS110-family serine recombinases have recently been shown to mediate programmable DNA recombination in bacteria by using a bispecific RNA guide (bridge RNA) that simultaneously recognizes target and donor sites. In this work, we have shown that the bridge recombinase ISCro4 is highly active in human cells and provided structural insights into its enhanced activity. Using plasmid- or all-RNA–based delivery, ISCro4 supports programmable multikilobase excisions and inversions and facilitates donor DNA insertion at genomic sites with efficiencies that exceed 6%. Last, we assessed ISCro4 specificity and off-target activity. These results establish a framework for the development of bridge recombinases as next-generation tools for editing modalities that are beyond the capabilities of current technologies.
mhryu@live.com's insight:

jinek, bridge recombinases can be repurposed for mammalian genome editing.

No comment yet.
Scooped by mhryu@live.com
March 20, 1:04 AM
Scoop.it!

A genetically encoded local learning rule enables physical learning in engineered bacteria | brvsb

A genetically encoded local learning rule enables physical learning in engineered bacteria | brvsb | RMH | Scoop.it

Training physical neural networks directly in matter remains difficult because most platforms do not implement weight storage and weight update within the same physical substrate. Here we show that engineered E. coli can implement a genetically encoded local learning rule acting on a persistent biological memory. In memregulons, analogue weights are stored as plasmid copy-number ratios in a coupled two-plasmid system and are rewritten by activity-dependent growth bias under a global negative learning signal. In single-strain cultures, theory predicts that the change in mean weight is proportional to the activity of the learning channel and to the standing variance of the stored distribution, and flow-cytometry trajectories across eight distinct promoters driving the learning channel support this prediction quantitatively. At the single-cell level, repeated negative learning also reshapes the stored distribution by narrowing it and increasing its skewness as weights approach the lower boundary. In mixed populations and nine-strain co-cultures, one global negative learning signal selectively rewrites only the active memregulons, enabling supervised adaptation in a bacteria-versus-bacteria tic-tac-toe tournament. We then generalise this principle across nine orthogonal chemical inputs and combinatorial promoters, including channels controlled by quorum-sensing molecules, and use it to rationally design a biological XOR gate. Finally, we examine multilayer ANN-like architectures with a human-in-the-loop protocol in which weight updates remain physically implemented and parameterised by experimental measurements, while inter-layer communication is supplied externally. These results establish a route to physical learning in living matter and provide a modular foundation for adaptive multicellular computation, paving the way for autonomous biological hardware capable of distributed environmental sensing and next-generation cellular therapeutics.

mhryu@live.com's insight:

jaramillo, By placing a kanamycin resistance gene under the same promoter that reports local activity, we convert a global negative learning signal (kanamycin) into a local negative weight update that acts only on active memregulon populations. P1 carries inducible mCherry together with functional chloramphenicol resistance fused to an inactive kanamycin-resistance module, and P2 carries inducible EGFP together with inactive chloramphenicol resistance fused to the functional kanamycin-resistance module 

No comment yet.
Scooped by mhryu@live.com
March 20, 12:42 AM
Scoop.it!

Context-informed subgraph foundation models enable interpretable protein-function prediction | csys

Context-informed subgraph foundation models enable interpretable protein-function prediction | csys | RMH | Scoop.it
Protein-function prediction is crucial for elucidating molecular mechanisms driving biological processes and therapeutics development. Despite numerous computational tools demonstrating promising performance, they fall short when predicting rare, uncharacterized functions or indirect activities. Here, we present COSMOS, a context-aware Gene Ontology (GO) subgraph mining system for protein-function prediction. By leveraging inductive subgraph foundation models and an enriched knowledge graph of protein-GO relationships, COSMOS performs zero-shot, few-shot, and low-homology protein-function prediction. Built on 7,923,952 functional semantic relationships, COSMOS demonstrates robust capabilities to (1) generate state-of-the-art predictions for GO classes with sparse or no experimental annotations, (2) provide interpretable functional subgraphs for transparent rationale analysis, and (3) deliver complementary benefits when integrated with existing embedding-based prediction methods. We anticipate that COSMOS will serve as a complementary approach to conventional protein annotation methods and an interpretable tool for predicting protein functions within underexplored GO classes, thereby advancing genomics and therapeutic research.
No comment yet.
Scooped by mhryu@live.com
March 20, 12:05 AM
Scoop.it!

PhyloRNA: a database of RNA secondary structures with associated phylogenies | brvsys

PhyloRNA: a database of RNA secondary structures with associated phylogenies | brvsys | RMH | Scoop.it

The ability to access, search, and analyse large collections of RNA molecules together with their secondary structure and evolutionary context is essential for comparative and phylogeny-driven studies. Although RNA secondary structure is known to be more conserved than primary sequence, no existing resource systematically associates individual RNA molecules with curated phylogenetic classifications. Here, we introduce PhyloRNA, a curated meta-database that provides large-scale access to RNA secondary structures collected from public resources or derived from experimentally resolved 3D structures. PhyloRNA allows users to search, select, and download extensive sets of RNA molecules in multiple textual formats, each entry being explicitly linked to phylogenetic annotations derived from five curated taxonomy systems. In addition to taxonomic information, each RNA molecule is accompanied by a rich set of descriptors, including pseudoknot order, genus, and three levels of structural abstraction - Core, Core Plus, and Shape - which facilitate comparative analyses across sets of molecules. PhyloRNA is publicly available at https://bdslab.unicam.it/phylorna/ and is regularly updated to incorporate newly available data and revised taxonomic annotations.

No comment yet.
Scooped by mhryu@live.com
Today, 2:25 PM
Scoop.it!

Chlorophyll a degradation in Prokaryotes | brvm

Chlorophyll a degradation in Prokaryotes | brvm | RMH | Scoop.it

Chlorophyll is one of the most abundant pigments on Earth. Although its degradation is well understood in plants, the role of prokaryotes in this process - despite their vast metabolic capabilities - remains unknown. Recent developments in the field of AI-predicted protein structures have opened new avenues for investigating functional homologies between evolutionary-distant organisms previously inaccessible through traditional sequence- or profile-based methods. Here, we present the first evidence of Chlorophyll a (Chl a) degradation by prokaryotes, discovered through a novel bioinformatic framework which bridges the gap across the domains of life via structural alignments of functionally characterised plant proteins, followed by structure similarity graph-based clustering. Metagenomic sequencing data was assembled and binned, yielding over 70,000 medium- to high-quality genomes in total, furthermore publicly available datasets containing genomes from prokaryotic isolates, metagenome-assembled genomes, as well as single-cell genomes were then mined for prokaryotic homologues of Chl a degradation genes. Our analysis revealed over 400 genomes from diverse taxonomic groups and habitats that possess a complete pathway, more than 50% stemming from isolates. Additionally, many other genomes harbor partial pathways, suggesting that Chl a degradation capabilities are globally widespread across diverse ecosystems. We then validated our in silico findings using the model organism Shewanella acanthi and confirmed its Chl a degradation capability via growth experiments, fluorescence spectroscopy and HPLC analyses. Our findings reveal a previously unrecognized pathway in prokaryotes, highlighting the power of structure-based remote homology detection for uncovering metabolic capabilities and evolutionary relationships.

mhryu@live.com's insight:

2st, mining, Structural homologs from A. thaliana-CCEs were identified in the ESM Metagenomic Atlas using Foldseek. The resulting structures were then all-vs-all aligned using Foldseek. A structural similarity graph was constructed using NetworkX [55], and clustered with the Markov cluster algorithm (MCL). After selecting the cluster with the highest profile similarity by searching them against curated plant HMMs using HH-suite, we obtained one final HMM per A. thaliana CCE. In parallel, we prepared publicly available MAGs, SAGs and isolate genomes, as well as own assemblies of MAGs from public metagenomics datasets, and screened them using our SH-CCE HMMs. The resulting alignments were used for phylogenetic and geographic analyses as well as for the selection of a type-strain available from a culture collection to be tested in vitro.

No comment yet.
Scooped by mhryu@live.com
Today, 1:56 PM
Scoop.it!

Multifaceted roles of extracellular vesicles in Agrobacterium fabrum C58 lifestyles | brvp

Multifaceted roles of extracellular vesicles in Agrobacterium fabrum C58 lifestyles | brvp | RMH | Scoop.it

Bacterial extracellular vesicles (EVs) constitute a key driver of interspecies and inter-kingdom communication, and shape bacterial ecology, yet their role as a dynamic delivery system remains underexplored. Here, we show that the plant pathogen Agrobacterium fabrum C58 modulates its EVs in response to virulence-inducing conditions. Our multi-omics analysis revealed that these virulence-state EVs are significantly enriched in effectors from the Type IV secretion system and toxins from the Type VI secretion system, which were previously known to be delivered by conventional contact-dependent mechanisms. We demonstrate that these EVs can directly transfer virulence effectors into plant host cells, enhancing tumor formation. Furthermore, we show that these EVs can interact with and influence the development of several environmental bacteria. Finally, A. fabrum C58 EVs elicit distinct plant host metabolome responses compared to whole cells. Our findings establish EVs as a crucial and dynamic component of bacterial virulence and inter-kingdom communication, providing a new perspective on how bacteria adapt to and manipulate their environment.

mhryu@live.com's insight:

omv

No comment yet.
Scooped by mhryu@live.com
Today, 1:05 PM
Scoop.it!

RNASTOP: A Deep Learning Framework for mRNA Chemical Stability Prediction and Optimization | brvai

RNASTOP: A Deep Learning Framework for mRNA Chemical Stability Prediction and Optimization | brvai | RMH | Scoop.it

Messenger RNA vaccines offer promising therapeutics for combating various diseases, yet their inherent chemical instability hampers their long-term efficacy. Although several methods have been developed to predict mRNA degradation, they exhibit limited accuracy and lack the capability for rational sequence optimization. Here, we propose RNASTOP, a novel framework integrating deep learning with heuristic search to simultaneously predict and optimize mRNA chemical stability. RNASTOP achieves a 13% accuracy improvement over the top-performing model on the Stanford OpenVaccine competition dataset and demonstrates robust generalization in predicting full-length mRNA degradation. Applied to mRNA codon optimization, RNASTOP reduces the minimum free energy of the Varicella-Zoster Virus vaccine sequence by 75.73% while maintaining high translation efficiency. Overall, RNASTOP serves as a powerful tool for predicting and optimizing mRNA chemical stability, poised to expedite the development of mRNA therapeutics. https://github.com/xlab-BioAI/RNASTOP 

No comment yet.
Scooped by mhryu@live.com
Today, 12:52 PM
Scoop.it!

ISdetector: precise mapping of insertion sequences and associated structural variations from short-read sequencing data | brvbi

ISdetector: precise mapping of insertion sequences and associated structural variations from short-read sequencing data | brvbi | RMH | Scoop.it

Insertion sequences (ISs) are key drivers of genomic plasticity in bacteria and archaea. Determining their exact insertion coordinates is critical for understanding drug resistance, virulence, and pathogen epidemiology. However, accurately mapping ISs from high-throughput short-read sequencing data remains challenging due to the repetitive nature of these elements and accompanying structural variations, which frequently confound standard alignment-based algorithms. As whole-genome sequencing becomes the standard for population-level studies, there is a need for robust, scalable, and specialized pipelines to detect ISs. We present ISdetector, a bioinformatics pipeline that detects precise insertion sites of specific ISs using an IS-clean reference strategy combined with clustering of IS-relevant signals from soft-clipped reads. Compared with existing tools, including ISMapper and MGEFinder, ISdetector demonstrates higher accuracy and robustness, achieving high F1 scores in both high-GC-content genomes (e.g., Mycobacterium tuberculosis, F1=0.91) and high-IS-burden genomes (e.g., Shigella sonnei, F1=0.85). Furthermore, ISdetector identifies IS movements accompanied by structural variations, such as large-scale deletions, which are often missed by existing methods. Implemented with multi-threading, ISdetector shows near-linear decreases in running time with increasing thread counts, making it highly scalable and efficient for processing large numbers of samples in population-level studies.

No comment yet.
Scooped by mhryu@live.com
Today, 12:41 PM
Scoop.it!

BioReason-Pro: Advancing Protein Function Prediction with Multimodal Biological Reasoning | brvai

BioReason-Pro: Advancing Protein Function Prediction with Multimodal Biological Reasoning | brvai | RMH | Scoop.it

Protein function annotation is fundamental to understanding biological mechanisms, designing therapeutics, and advancing biomedical research. Current computational methods either rely on shallow sequence similarity or treat function prediction as isolated classification tasks, failing to capture the integrative reasoning across sequence, structure, domains, and interactions that expert biologists perform to infer function. We introduce BioReason-Pro, the first multimodal reasoning large language model (LLM) for protein function prediction that integrates protein embeddings with biological context to generate structured reasoning traces. A key input into BioReason-Pro is the set of GO term predictions made by GO-GPT, our autoregressive transformer that captures hierarchical and cross-aspect dependencies of GO terms. BioReason-Pro is trained via supervised fine-tuning on synthetic reasoning traces generated by GPT-5 for over 130K proteins and further optimized through reinforcement learning. It achieves 73.6% Fmax on GO term prediction and an LLM judge score of 8/10 on functional summaries, substantially outperforming previous methods. Evaluations with human protein experts show that BioReason-Pro annotations are preferred over ground truth UniProt annotations in 79% of cases. Remarkably, BioReason-Pro de novo predicted experimentally confirmed binding partners with per-residue attention localizing to the exact contact residues resolved in cryo-EM structures of those complexes. Together, GO-GPT and BioReason-Pro establish a framework for protein function prediction that combines precise ontology modeling with interpretable biological reasoning.

mhryu@live.com's insight:

hsu pd

No comment yet.
Scooped by mhryu@live.com
Today, 12:25 PM
Scoop.it!

Engineered Bacteria-Vesicle Delivered Lactate Reprogramming Boosts Tumor Radiosensitivity | advS

Engineered Bacteria-Vesicle Delivered Lactate Reprogramming Boosts Tumor Radiosensitivity | advS | RMH | Scoop.it

Radiotherapy (RT) remains a cornerstone in cancer treatment, yet its efficacy is often compromised by tumor-acquired radioresistance, driven in part by lactate accumulation in the tumor microenvironment (TME). Lactate fosters therapeutic resistance through aberrant DNA repair, immunosuppression, and metabolic reprogramming, posing a formidable clinical challenge. Here, we report a precision microbial therapy leveraging engineered E. coli Nissle 1917 (EcNΔnlpIIHCL, ENHL) to target and deplete lactate in the TME. By utilizing engineered bacteria with nlpI gene deletion to enhance outer membrane vesicles (OMVs) biogenesis and introducing a bifunctional surface display system (INP-HlpA for tumor targeting and ClyA-EGFP for tracking), ENHL delivers lactate oxidase (LOx) to neutralize acidic stress. In vitro and in vivo studies confirm that ENHL and LOx-loaded OMVs effectively radiosensitize colorectal cancer cells by depleting tumor-derived and radiation-induced lactate. Oral administration of ENHL selectively colonizes tumors, where arabinose induction triggers localized LOx expression, significantly improving radiosensitivity and immune cell infiltration while modulating gut microbiota. This synergistic approach—combining targeted metabolic modulation with microbial precision therapy—represents a transformative strategy to overcome RT resistance in colorectal cancer, offering a promising pathway toward clinical translation.

mhryu@live.com's insight:

2st, ENHL was administered by oral gavage administration, with tumor irradiation (4 Gy dose) performed after a 12-hour interval.

No comment yet.
Scooped by mhryu@live.com
Today, 12:00 PM
Scoop.it!

Pathogen effector tactics to suppress plant endomembrane system | frn

Pathogen effector tactics to suppress plant endomembrane system | frn | RMH | Scoop.it

Plants have evolved sophisticated defense mechanisms to counter pathogen invasion, including the production of antimicrobial compounds, regulation of defense-related protein expression, and the synthesis of defense hormones across various subcellular organelles. While the significant contribution of organelle functions in plant immunity is increasingly recognized, the specific roles of these organelles in the immune response remain poorly understood. Recent studies have revealed that pathogen effectors from diverse microbes such as fungi, oomycetes, and bacteria localize within various organelles. These effectors target host proteins to manipulate the plant immune system, underscoring the crucial role of organelle functions in plant immunity. This review not only focuses on the localization of effectors within subcellular organelles, excluding the nucleus, but also explores the implications of organelle functions in the plant immune response. Gaining a deeper understanding of how these effectors interact with their targets in specific organelles will pave the way for developing disease-resistant plants.

No comment yet.
Scooped by mhryu@live.com
Today, 11:52 AM
Scoop.it!

A Modular Platform for Quantitative Two-Color Bioluminescence Combining NanoLuc and Red-Shifted NanoPrism Luciferases | acs

A Modular Platform for Quantitative Two-Color Bioluminescence Combining NanoLuc and Red-Shifted NanoPrism Luciferases | acs | RMH | Scoop.it

Bioluminescent reporters are widely used to monitor and image biological processes. Among these, NanoLuc luciferase and its complementation variants (LgBiT/SmBiT and LgBiT/HiBiT) are commonly used due to their brightness, sensitivity, and compatibility with prolonged kinetic measurements. However, the single-channel emission of these NanoLuc-based systems (460 nm peak) limits their use in multiplexed assays. Prior efforts to shift NanoLuc’s emission employed bioluminescence resonance energy transfer (BRET) to a proximal fluorescent protein or organic fluorophore. Building on this concept, we engineered high-efficiency BRET reporters, termed NanoPrism luciferases, by inserting circularly permuted NanoLuc or LgBiT into a surface loop of the self-labeling HaloTag protein. These NanoPrisms achieve a ∼90% BRET efficiency by optimally positioning NanoLuc variants near a fluorophore covalently bound to HaloTag. The binary design further supports high- and low-affinity complementation, allowing applications in HiBiT knock-in cells and tracking protein–protein interactions, respectively. Pairing red-shifted NanoPrisms with unmodified NanoLuc or its complementation variants, we created a two-color bioluminescent reporter platform featuring bright signals of similar intensity and >100 nm spectral separation, allowing quantitative, simultaneous measurement of two molecular readouts within the same sample. Here, we demonstrate the platform’s utility for monitoring a degradation target alongside a control protein and for tracking two distinct events within a biological pathway, using plate-based detection and bioluminescence imaging. By enabling concurrent measurements within the same sample, the system provides insights into cellular dynamics while reducing variability and complexity associated with parallel single-channel assays.

mhryu@live.com's insight:

1str, reporter

No comment yet.
Scooped by mhryu@live.com
March 20, 1:36 AM
Scoop.it!

SypC, a symbiont outer membrane vesicle protein, impacts the development of the squid–vibrio partnership | pnas

SypC, a symbiont outer membrane vesicle protein, impacts the development of the squid–vibrio partnership | pnas | RMH | Scoop.it
Bacterial outer membrane vesicles (OMVs) and the cargo they carry are increasingly recognized as a means of communication between microbial symbionts and the cells of their host. However, few studies have focused on the biochemical and molecular mechanisms underlying OMV signaling during symbiosis onset and development. We show here that SypC, an OMV protein of the bioluminescent symbiont Vibrio fischeri, is taken up by cells of the squid host Euprymna scolopes where it assumes a new function, i.e., the facilitation of symbiont-induced light-organ morphogenesis. SypC is a Wza-like outer membrane protein found in host-associated Vibrionaceae and is essential for V. fischeri biofilm formation. Colonization or direct treatment with V. fischeri OMVs triggers host development, which was reduced or delayed if the host is instead exposed to a ∆sypC mutant or ∆sypC OMVs. RNA-seq analyses comparing light organs colonized by either the mutant or its parent revealed differential expression of host genes associated with immune responses and tissue morphogenesis. In immunocytochemical imaging, SypC-bearing OMVs were taken up by the host’s macrophage-like cells near the light-organ crypts, revealing the mechanism by which SypC travels through tissue to trigger morphogenesis. Taken together, the data provide evidence that in addition to its role in biofilm formation and colonization, SypC has a second function promoting the induction of symbiotic-tissue development. These findings provide a critical piece of a puzzle whereby a rich array of host and symbiont molecules work in concert to orchestrate normal symbiont colonization and host development within the first hours to days of symbiosis.
mhryu@live.com's insight:

1str

No comment yet.
Scooped by mhryu@live.com
March 20, 1:23 AM
Scoop.it!

Interspecies transfer of giant virulence-factor-like proteins in a bacterial symbiosis | brveco

Interspecies transfer of giant virulence-factor-like proteins in a bacterial symbiosis | brveco | RMH | Scoop.it

The transfer of virulence factors into eukaryotic cells is a hallmark of bacterial pathogenesis. We report the expression, interspecies transfer, subcellular localization, and potential functions of three unusually large virulence factor-like proteins that underlie a bipartite mutualistic bacterial symbiosis. These proteins are synthesized by green sulfur bacterial epibionts surrounding a central motile chemoheterotroph in the multicellular phototrophic consortium 'Chlorochromatium aggregatum'. While symbiosis-proteins remain intracellular during axenic epibiont growth, they are transferred to the partner bacterium in the association. An RTX-like protein secreted towards the central bacterium is capable of degrading its alginate capsule, thereby promoting direct cell-to-cell contact. Two gigantic hemagglutinin-like proteins are predicted to fold when binding extracellular Ca2+ to form Type 6-like auto injection needles, explaining their observed transfer into the central bacterium. These functionalities extend far beyond the known pathogenic interactions of bacteria with eukaryotes and provide new perspectives on the evolution of bacterial virulence factors.

No comment yet.
Scooped by mhryu@live.com
March 20, 12:46 AM
Scoop.it!

Methane-fed microbial communities enriched from field-grown rice support diverse heterotrophic bacteria | fems

Methane-fed microbial communities enriched from field-grown rice support diverse heterotrophic bacteria | fems | RMH | Scoop.it

Rice paddies naturally host methane-oxidizing bacteria known as methanotrophs, due to the production of methane in flooded soils. Enhancing the activity of native methanotrophs could improve the sustainability of rice cultivation, but knowledge of how this could impact other members of the rice microbiome remains incomplete. To gain insight into which members of the rice microbiome might benefit from increased methanotrophic activity, we passaged 51 aerobic microbial enrichment cultures from rice rhizosphere and tissue samples in a chemically-defined medium with methane as the primary carbon source and electron donor. We profiled the cultures over time by 16S rRNA gene amplicon sequencing and sequenced the genomes of 44 isolates to gain functional insights. Taxa whose relative abundance increased during community growth on methane represented more than a dozen families, many of which are not known to utilize one-carbon substrates. Several of the enriched genera have not previously been linked to methane cycling in rice fields, and genomic analysis of the sequenced isolates revealed considerable variation in predicted carbon source utilization and nitrogen cycling capabilities. Together, these findings broaden the understanding of how aerobic methanotrophs may impact microbiome assembly and nutrient cycling in rice paddies.

No comment yet.
Scooped by mhryu@live.com
March 20, 12:09 AM
Scoop.it!

Ancestral Hydrocarbon Metabolism Enables PET Degradation by a Natural Bacterial Consortium | brvm

Ancestral Hydrocarbon Metabolism Enables PET Degradation by a Natural Bacterial Consortium | brvm | RMH | Scoop.it

Plastic biodegradation in natural environments is increasingly recognized as a multi-organism process, yet the mechanisms enabling coordinated depolymerization and metabolism of polyethylene terephthalate (PET) remain poorly understood. Previously, we demonstrated that a full consortium containing three Pseudomonas and two Bacillus strains isolated from hydrocarbon-rich coastal soils of Galveston Bay, Texas, can synergistically depolymerize PET plastic and utilize it as a sole carbon source, a capacity not observed in individual isolates. In this report, using integrated comparative genomics, proteomics, and chemical analyses, we show that PET degradation in this system reflects exaptation of hydrocarbon metabolism reinforced by metabolic division of labor. Within this naturally occurring consortium, Bacillus strains persist under environmental stress, establish biofilms, and perform essential secondary hydrolysis, while Pseudomonas strains catabolize aromatic monomers and buffer oxidative stress. Genes supporting these functions are enriched within the accessory genomes of the consortium strains, indicating consortium-enriched horizontal gene transfer (HGT). In addition to the canonical two-step hydrolytic pathway well documented in PET biodegradation, we identify a secondary methylation- and redox-associated process, mechanisms where the full consortium acts on the oligomer mono(2-hydroxyethyl) terephthalate (MHET), yielding nearly complete conversion to terephthalic acid (TPA) and methylated MHET (MMHET). Together, these findings demonstrate how cooperation and competition within consortia facilitate targeted gene exchange, enabling emergent plastic biodegradation in natural microbial communities.

No comment yet.