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mhryu@live.com
Today, 12:38 AM
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The emergence of a chemical system capable of self-replication and evolution is a critical event in the origin of life. RNA polymerase ribozymes can replicate RNA, but their large size and structural complexity impede self-replication and preclude their spontaneous emergence. Here we describe QT45: a 45-nucleotide polymerase ribozyme, discovered from random sequence pools, that catalyzes general RNA-templated RNA synthesis using trinucleotide triphosphate (triplet) substrates in mildly alkaline eutectic ice. QT45 can synthesize both its complementary strand using a random triplet pool at 94.1% per-nucleotide fidelity, and a copy of itself using defined substrates, both with yields of ~0.2% in 72 days. The discovery of polymerase activity in a small RNA motif suggests that polymerase ribozymes are more abundant in RNA sequence space than previously thought.
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mhryu@live.com
Today, 12:29 AM
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By 2050, the death toll from previously preventable or easily curable bacterial infections is projected to surpass that caused by cancer, unless we prevent the spread of antibiotic resistance and develop new therapies. A promising approach is phage therapy, which exploits bacteriophages, natural predators of bacteria. However, bacteria fight back, which can limit its efficacy. Notably, many bacteria rely on cell-cell communication, known as quorum sensing, to orchestrate both virulence programs and phage defenses. To circumvent these, we have engineered anti-quorum sensing phages against the human pathogen Pseudomonas aeruginosa. Our engineered phages effectively degrade quorum-sensing molecules, reduce virulence factor production, and double the survival of P. aeruginosa-infected Galleria mellonella larvae. Moreover, we demonstrate that the anti-quorum sensing phages inhibit quorum sensing in mixed populations of phage-susceptible and phage-resistant cells, demonstrating the ability of the phages to disarm subpopulations phage-resistant P. aeruginosa, which often are selected for during phage treatment. Together, our findings highlight the future therapeutic promise of anti-quorum sensing phages as a dual-action strategy in killing susceptible cells while attenuating virulence across the bacterial population. This approach has the potential to enhance the robustness of phage therapy.
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mhryu@live.com
February 17, 10:01 PM
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Accurate annotation of coding sequences and translational features within transcript models is essential for interpreting assembled transcriptomes and their functional potential. Existing open reading frame (ORF) prediction tools typically operate on transcript FASTA files and do not reintegrate coding sequence (CDS) information back into transcript models, limiting their utility in long-read sequencing workflows where GTF/GFF annotations are the primary output. We present ORFannotate, a lightweight, GTF-native Python command-line tool that predicts ORFs from transcript annotations and reinserts precise, exon-aware CDS and UTR features into the original GTF/GFF file. In addition, ORFannotate provides biologically informative translational context by annotating Kozak sequence strength, detecting non-overlapping upstream ORFs (uORFs) with coding probabilities, characterising 5′ and 3′ untranslated regions (UTRs), and predicting nonsense-mediated decay (NMD) susceptibility. All annotations are consolidated in a transcript-level summary to support downstream analysis. By generating GTF files with accurate CDS annotations, ORFannotate facilitates reproducible analysis of both long- and short-read transcriptomes and integrates seamlessly with visualization tools, genome browsers, and comparative transcript analysis workflows. ORFannotate is fast, scalable and provides a practical solution for transcriptome annotation beyond coding potential prediction alone.
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mhryu@live.com
February 17, 5:09 PM
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Agrobacterium-mediated transformation relies on binary vectors in which T-DNA and virulence genes are maintained on separate replicons. While Golden Gate cloning has become standard for T-DNA assembly, no modular framework exists for systematic construction of Agrobacterium vector backbones. Here, we present BackBone Builder (B3), a Golden Gate-based platform for combinatorial backbone assembly. B3 uses the Type IIS enzyme PaqCI to minimize domestication and enables one-pot assembly of nine backbone modules plus a selectable cloning cassette. The system is compatible with GreenGate and remains independent of downstream cloning strategies. We generated a library of 42 backbone components, supporting a theoretical design space exceeding 370,000 constructs. A 4 x 4 origin-of-replication (ORI) matrix combining four Escherichia coli and four Agrobacterium ORIs assembled with 100% efficiency and functioned robustly in bacterial and plant contexts. Reporter expression reflected expected ORI-dependent patterns in E. coli, Agrobacterium, and Nicotiana benthamiana. A B3-derived maize transformation backbone achieved stable transformation efficiencies comparable to established vectors. B3 establishes a standardized and extensible framework for rational engineering of Agrobacterium binary vector architecture.
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mhryu@live.com
February 17, 5:05 PM
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Enzymatic recycling of polyethylene terephthalate (PET) provides a sustainable alternative to conventional PET waste treatment, but the scalable production of PET-degrading enzymes remains a challenge. A key bottleneck is intense cell lysis during production, caused by the PET hydrolases attacking the host cell membrane. This lysis leads to elevated extracellular DNA content, increased viscosity, excessive foaming, reduced oxygen transfer during fermentation, and difficulties in downstream processing such as filtration and centrifugation. In this study, we explored two strategies to address these issues: (1) the addition of nucleases during fermentation, and (2) co-cultivation of PETase- and nuclease-expressing E. coli strains in varying inoculum ratios. To stabilize population distribution during the production phase of co-cultivation, we employed a growth-decoupled expression system. Both strategies reduced extracellular DNA, lowered broth viscosity, and improved cell settling and foam control, while maintaining or even enhancing PET hydrolase activity and titer. While adding nuclease to produce PETase may increase production costs, co-cultivation provides a promising alternative to simplify processing. Our findings offer a scalable and cost-efficient strategy for producing lysis-prone enzymes, enabling robust fermentation processes for industrial enzymatic PET recycling.
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mhryu@live.com
February 17, 4:57 PM
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Isoprenoids play vital roles in all domains of life, from beta-carotene in bacteria to heme in humans. Two distinct metabolic pathways have evolved to synthesize the critical precursor of all mature isoprenoids: the mevalonate (MEV) and the methylerythritol phosphate (MEP) pathways. Here, we quantify the extensive inter- and intra-genus heterogeneity in the usage of these two pathways with particular emphasis on rare bacteria that encode both, or neither, pathways. Furthermore, MEP intermediates themselves have non-isoprenogenic roles that may underlie evolutionary pressures driving pathway diversification. Understanding isoprenoid biosynthesis in bacteria offers new avenues toward more sustainable engineering of economically relevant molecules in microbes.
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mhryu@live.com
February 17, 4:29 PM
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Within the vast Bacillus cereus group, two bacterial species have stood out for over a century: Bacillus anthracis for its pathogenicity to mammals, and Bacillus thuringiensis for its remarkable and economically exploitable activity against invertebrates. One hundred years of extensive research around the world have unraveled the sophisticated mechanisms that make B. thuringiensis a formidable weapon designed to kill insects, exploiting them as an ecological niche for its proliferation. Evolution has led to the selection of a great diversity of highly specific toxins targeting a wide range of insects and nematodes. Bacteria have developed transcriptional, post-transcriptional, and post-translational mechanisms that enable the massive production of these toxins as crystalline inclusions. Virulence and adaptation factors, together with regulation systems, have also been selected to enable the bacterium to make the most of the ecological niche provided by insects. In addition to their interest in the bacterium, the biological tools and processes developed by B. thuringiensis can be exploited by mankind to create insect-resistant plants, overproduce proteins, crystallize them, and gain a better understanding of the microbial world. All the research carried out on B. thuringiensis over the last century has made this bacterium a remarkable study model and biotechnological resource, revealing all the subtlety and power of the mechanisms that a microorganism has been able to acquire in the course of its evolution.
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mhryu@live.com
February 17, 4:05 PM
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In a recent Breakthrough Report, Jiarong Chen, Yanlei Feng, Yuchan Zhang, and colleagues (Chen et al. 2026) used a structure-based approach that goes beyond the traditional sequence alignment to systematically annotate previously uncharacterized plant proteins and predict their functions (Fig. 1). Analyzing protein structures from 17 flowering plant species, the team clustered >550 K predicted proteins into >170 K groups based on structural similarity. From these, they identified more than 3,000 clusters where structural alignment revealed conserved architectures that sequence-based methods missed. Further refinements narrowed this set to 1,292 high-quality protein clusters, of which 246 clusters were broadly conserved across many plant species. By manual curation, the team ultimately highlighted 120 protein clusters widely present across plants and with predicted functions that could not be inferred from sequence data alone.
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mhryu@live.com
February 17, 3:38 PM
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This study provides the first clear evidence that edible mushrooms, such as Lentinula edodes (shiitake), Pleurotus ostreatus and Pleurotus eryngii, can generate carbon monoxide (CO) as part of their metabolic activity—independent of bacteria, illumination or oxygen limitation. Systematic measurements of CO and CO2 emissions were performed over 60 days using multiple fungal species, substrates and growth conditions. Microscopy observations (light, scanning and transmission electron microscopy) confirmed no extracellular and intracellular bacterial endosymbionts involved, supporting a fungal genesis of CO. CO emission patterns showed a parabola-shaped curve, correlating with CO2 levels regardless measurements by gas-analyser or GC–MS and peaking during full mycelial colonization. Shiitake mushrooms grown on birch substrate released the highest CO compared to alder and aspen substrates and P. ostreatus and P. eryngii. These findings suggest that fungal respiration contributes to CO dynamics more than previously recognized and highlight the need for further research into its mechanisms and environmental and occupational health implications.
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mhryu@live.com
February 17, 11:14 AM
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Cas9-based genome engineering is a powerful tool for yeast strain development, but its use in the food industry is limited due to GMO concerns. As a non-GMO alternative, adaptive laboratory evolution (ALE) was applied to enhance trehalose accumulation, a stress protectant, in Saccharomyces cerevisiae. To avoid ethanol-centric metabolism and promote storage carbohydrate production, ALE was conducted under nitrogen limitation with ethanol as the sole carbon source. The evolved strain 65EV showed a 2.3-fold increase in trehalose (11.51% vs 5.25%), resulting in enhanced cell viability (77.7% vs 5.11%) and bread loaf volume (107.2 mL vs 61.5 mL) after freeze/thaw stress. Amino acid profiling revealed distinct metabolic shifts, including elevated intracellular proline and extracellular glutamate. Whole-genome sequencing and reverse engineering identified unique mutations, TSL1 (V887A) and SSA2 (F105L), associated with trehalose regulation. These findings demonstrate potential of ALE as a non-GMO strategy for improving yeast performance in food applications.
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mhryu@live.com
February 17, 11:08 AM
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Maintaining proper redox conditions is essential for protein stability and function. In cell-free protein synthesis, reducing agents, such as dithiothreitol and reduced glutathione, are commonly added to mimic the cytosolic environment and prevent unwanted oxidation. The PURE system, which is a fully reconstituted protein synthesis system, also contains reducing agents. Here, we systematically examined how reducing agents affect the protein synthesis in the PURE system. We found that the reducing activity of dithiothreitol decreased during prolonged reactions, leading to the formation of disulfide bonds in synthesized proteins. Dissolved oxygen and contaminating metal ions were identified as major factors causing this loss of activity. Based on these findings, we developed a method to maintain reducing conditions throughout the reaction, ensuring consistent protein quality. Our results provide new insights into redox regulation in cell-free systems and offer a practical strategy for the efficient synthesis of functional proteins, with potential applications in biotechnology and therapeutic protein production.
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mhryu@live.com
February 17, 11:00 AM
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Annotation of genes and transcripts is a key prerequisite for understanding the information that is encoded in newly sequenced genomes. One source of information suited for this purpose is RNA-seq data mapped to the respective genome sequence. RNA-seq-based approaches for transcript reconstruction generate transcript models from these data by combining regions of contiguous coverage (exons) and split read mappings (introns). Understanding phenotypes as a consequence of proteins encoded in a genome further requires the annotation of coding sequences within transcript models. We present GeMoSeq, a novel approach for transcript reconstruction from RNA-seq data that combines combinatorial enumeration of candidate transcripts with heuristics for splitting candidate transcripts into regions of contiguous coverage and subsequent likelihood-based quantification. Prediction of coding sequences is an integral part of the GeMoSeq algorithm. We benchmark GeMoSeq against previous approaches using a large collection of public RNA-seq data for seven species. For the majority of species, we observe an improved prediction performance of GeMoSeq, especially on the level of coding sequences and for species with dense genomes. We combine GeMoSeq with the homology-based approach GeMoMa to re-annotate two recently sequenced genomes of Nicotiana benthamiana lab strains, which illustrates the main purpose of GeMoSeq: the initial annotation of newly sequenced genomes with protein-coding genes.
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mhryu@live.com
February 17, 10:31 AM
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Extracellular electron transfer (EET) is essential for electroactive microbes’ physiology and biotechnological applications. Many such microbes are Gram-negative bacteria, in which EET must cross two membranes and the periplasm, necessitating spatial and temporal collaborations of various EET proteins that reside at different cellular compartments, for which little is known. Using single-molecule/single-cell-level fluorescence microscopy and electrochemical manipulations, we discover that in the electroactive bacterium Shewanella oneidensis, the inner-membrane electron-transfer hub protein CymA undergoes spatial reorganization into localized regions during active EET with dispersed formation dynamics, subsequently driving the colocalization of its direct electron-transfer partners in the periplasm. Correlated single-cell-level photoelectrochemistry-fluorescence microscopy further proves the critical function of CymA reorganization in enabling EET. A multitude of evidence suggests that CymA reorganization stems from biomolecular condensate formation, likely initiated by association with menaquinone-rich inner-membrane domains. These orchestrated spatiotemporal protein dynamics extend the functional roles of biomolecular condensates to include facilitation of EET in bacteria, with broader implications for cellular processes. Extracellular electron transfer (EET) in bacteria requires the spatiotemporal coordination of many proteins. Here, authors show that the inner-membrane protein CymA reorganizes spatially into condensates and drives the colocalization of partner proteins to enable EET in Shewanella.
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mhryu@live.com
Today, 12:35 AM
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Ribosomally synthesized and post-translationally modified peptides (RiPPs) are secondary metabolites produced by bacteria, plants, animals, and fungi. Canonical fungal RiPP precursors possess a leader sequence cleaved during maturation. The first RiPPs described in fungi were the MSDIN-derived peptides responsible for the toxicity of lethal Amanita mushrooms. In this study, we upend the conventional understanding of fungal RiPPs, discovering a subclass that has diversified and lacks a leader sequence, an empirical example of leaderless RiPPs in fungi. We use a combinatorial analysis of NMR and MS/MS with an updated bioinformatic pipeline to pair MSDIN genes to leaderless peptides in Amanita phalloides, a European species spreading in California. Leaderless MSDIN transcripts are expressed several orders of magnitude more than most canonical MSDINs, with significantly higher expression in invasive populations. Our results redefine the understanding of fungal RiPP architectures and suggest differential regulation of non-canonical RiPPs may contribute to the invasion biology of the world’s deadliest mushroom.
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mhryu@live.com
February 17, 10:07 PM
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DNA-encoded library (DEL) technology enables high-throughput small-molecule discovery but is typically performed using purified proteins under in vitro conditions that do not reflect native intracellular environments. Here, we present a microfluidic agarose microdroplet platform for cellular-context DEL screening. The porous hydrogel droplets provide mechanically stable yet permeable microenvironments that protect weak protein-ligand interactions while enabling efficient buffer exchange and ligand diffusion. Importantly, mild cell permeabilization within droplets selectively retained chromatin-associated proteins, allowing screening directly in a cellular context. Using BRD4 as a model target, we validated intracellular ligand engagement by fluorescence imaging and super-resolution microscopy. Small-scale DEL screening selectively enriched JQ1 in both bead-based and cell-based formats, and large-scale DEL screening across millions of encoded compounds successfully identified hit molecules by sequencing. This agarose microdroplet based strategy expands DEL technology toward biologically relevant and chromatin-associated targets under near-native conditions.
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mhryu@live.com
February 17, 9:53 PM
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Proteins function through hierarchical modules, yet conventional models treat sequences as linear strings of residues, overlooking the recurrent multi-residue patterns-or "Protein Words"-that govern biological architecture. We introduce a physics-aware framework that discretizes protein space into a learnable vocabulary derived from the evolutionary record. By encoding proteins as sequences of discrete "words," our model captures higher-order structural and functional signals inaccessible to residue-level models, achieving highly competitive performance against widely established baselines in remote homology and mutation effect prediction. Analysis across 54 species reveals that these words track evolutionary complexity, specifically identifying the expansion of eukaryotic disordered regions. We demonstrate the discovery potential of this semantic axis by identifying ADMAP1 as a previously uncharacterized regulator of sperm motility, validated via CRISPR-Cas9 knockout mice. Finally, this vocabulary enables programmable design, generating functional cofilin variants despite high sequence divergence. This work establishes a linguistically inspired framework for deciphering the dark proteome and engineering biological function.
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mhryu@live.com
February 17, 5:08 PM
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RNA structures are essential for understanding their biological functions and developing RNA-targeted therapeutics. However, accurate RNA structure prediction from sequence remains a crucial challenge. We introduce DRfold2, a deep learning framework that integrates a novel pre-trained RNA Composite Language Model (RCLM) with a denoising structure module for end-to-end RNA structure prediction. Based solely on single sequence, DRfold2 achieves superior performance in both global topology and secondary structure predictions over other state-of-the-art approaches across multiple benchmark tests from diverse species. Detailed analyses reveal that the improvements primarily stem from the RCLM’s ability to capture co-evolutionary pattern and the effective denoising process, with a more than 100% increase in contact prediction precision compared to existing methods. Furthermore, DRfold2 demonstrates high complementarity with AlphaFold3, achieving statistically significant accuracy gains when integrated into our optimization framework. By uniquely combining composite language modeling, denoising-based end-to-end learning, and deep learning-guided post-optimization, DRfold2 establishes a distinct direction for advancing ab initio RNA structure prediction.
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Scooped by
mhryu@live.com
February 17, 5:01 PM
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While current genetic tools easily enable transfer of metabolic genes among bacteria, their effective nesting in the recipients depends on biochemical and regulatory compatibilities of the introduced pathway with those of the host. This issue becomes evident in e.g. attempts to engineer bacteria to degrade 2,4-dinitrotoluene (DNT), a xenobiotic compound naturally broken down—if quite ineffectively—by Burkholderia sp. DNT through the so-called dnt route. That despite multiple efforts no strain engineered with a complete set of dnt genes has been able to grow on DNT as sole carbon and nitrogen source suggests that new hosts need to go through a mutual chassis-implant adaptation process for successful degradation of this xenobiotic. To explore a possible roadmap for this to happen we have applied Adaptive Laboratory Evolution (ALE) to a Pseudomonas putida designed to carry an active dnt pathway but initially unable to grow on DNT. Over 315 days of selective subculturing, evolved strains emerged that could metabolize DNT as the sole growth substrate. Genetic and phenotypic analyses of the best-performing isolate revealed a large number of adaptations that improved stress tolerance and fine-tuned to host’s metabolic context to the newly introduced route. These results expose the occurrence of a sort of molecular negotiation between the incoming genes and the pre-existing molecular network of the host before cells entirely integrate the new pathway into their biochemical complement.
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mhryu@live.com
February 17, 4:43 PM
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In contrast to living organisms, viruses were long thought to lack protein synthesis machinery and instead depend on host factors to translate viral transcripts. Here, we discover that giant DNA viruses encode a distinct and functional IF4F translation-initiation complex to drive protein synthesis, thereby blurring the line between cellular and acellular biology. During infection, eukaryotic IF4F on host ribosomes is replaced by an essential viral IF4F that regulates viral translation, virion formation, and replication plasticity during altered host states. Structural dissection of viral IF4F reveals that the mRNA cap-binding subunit mediates exclusive interactions with viral mRNAs, constituting a molecular switch from translating host to viral proteins. Thus, our study establishes that viruses express a eukaryotic translation-initiation complex for protein synthesis, illuminating a series of evolutionary innovations in a core process of life.
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mhryu@live.com
February 17, 4:20 PM
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RNA interference (RNAi) is a crucial biological post-transcriptional gene silencing mechanism where small interfering RNA (siRNA) guides RNA-induced silencing complex (RISC) to bind with messenger RNA (mRNA) thereby silencing it and stopping protein formation. We exploit this process to prevent the formation of harmful proteins by silencing mRNA before it is translated into protein through an effective siRNA. There exists a need to develop a computational model that predicts the effectiveness of siRNA on a given mRNA. Designing a model is challenging, as the data availability is either scarce or biased, and existing models lack generalization ability, even though the parameters to training samples ratio is very high. To overcome these challenges, we introduce RNAiSpline, which incorporates self-supervised pretraining and fine-tuning with Kalmogorov-Arnold Network (KAN), Convolutional Neural Network (CNN), and Transformer Encoder. Evaluation on the independent test dataset yields an ROC-AUC of 0.8175, an F1 score of 0.7717, and Pearson correlation of 0.6032, making RNAiSpline a robust model for siRNA efficacy prediction.
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mhryu@live.com
February 17, 3:57 PM
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Transcriptional regulation lies at the heart of cellular identity and function, hinging on the precise binding of transcription factors (TFs) and cofactors to gene regulatory elements such as promoters and enhancers. Although it is relatively routine to profile genome-wide DNA binding landscapes of proteins, identifying the specific proteins that bind to, and regulate the transcription of, a particular gene of interest (GOI) remains a persistent experimental and conceptual challenge. This gene-centric question is complicated by the multilayered regulatory environment in which each gene resides, comprising 3D chromatin structure, enhancer–promoter looping, DNA accessibility, histone modifications, and cell state–dependent protein dynamics. In this review, we dissect the strengths, limitations, and biological relevance of current approaches for studying direct protein–DNA interactions, distinguishing between protein-centric and DNA-centric methodologies. We introduce a conceptual matrix of biological relevance, integrating the origin of DNA and protein elements (cis and trans) to evaluate false-positive and false-negative risks across experimental systems. Moreover, we explore how perturbation strategies—gain and loss of function—can complement steady-state profiling to establish causality in gene regulation. By critically examining both established tools and emerging techniques such as genome editing, synthetic chromosomes, and high-resolution imaging, we provide a practical framework for investigators seeking to uncover direct regulators of specific genes. Our goal is to guide the design of experiments that balance biological relevance, sensitivity, and interpretability to ultimately answer a deceptively simple question: What TFs directly regulate the expression of my GOI?
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mhryu@live.com
February 17, 2:53 PM
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Microbial lipids offer a promising alternative to petrochemicals, but high associated costs and low conversion efficiencies pose barriers to their commercialisation. In particular, sugar-based feedstocks are too expensive for the production of commodity chemicals, and recently attention has turned to volatile fatty acids (VFAs) as a cheaper, more widely available carbon source. Acidogenic fermentation can be used to produce high concentrations of VFAs from municipal and agricultural waste. By harnessing metabolically engineered Acinetobacter baylyi ADP1, the suitability of VFAs as sole carbon sources for wax ester (WE) production was investigated. These studies resulted in the highest WE accumulation in ADP1 achieved to date, at 37% of cell dry weight, and the first reported production of bacterial WEs from a raw, mixed waste stream, utilizing fermentate as the sole carbon source. WE titres of over 160 mg/L from VFAs were achieved, highlighting the unique benefits of mixed feedstocks typically considered problematic for bioproduction. Finally, the potential advantages of employing fermentates rich in longer chain VFAs are explored. In synthetic media, WE titres up to 190 mg/L were achieved, but translation to fermentate was challenging, emphasising the need for continued research in this area.
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mhryu@live.com
February 17, 11:11 AM
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Lactic acid bacteria (LAB), a group of Gram-positive bacteria widely used in food fermentation, are major producers of bacteriocins─ribosomally synthesized antimicrobial peptides. These peptides have attracted considerable attention not only as natural food preservatives but also for their therapeutic potential in biomedicine. This review outlines LAB-derived bacteriocins, presenting an updated classification (Classes I–III) by structure and genetics, along with their biosynthesis and gene clusters. Furthermore, key production influencers, such as quorum sensing, two-component systems, and culture conditions, are analyzed. Besides, this review also highlights the health benefits of LAB bacteriocins against infections and cancers, achieved via mechanisms like membrane disruption. It also discusses strategies (e.g., metabolic engineering and synthetic biology, combination therapies, and novel purification methods) to enhance efficacy. Despite persistent challenges in yield optimization and clinical translation, this work provides critical insights to guide the therapeutic development and scalable production of bacteriocins.
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mhryu@live.com
February 17, 11:05 AM
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Non-genetic variability in gene expression is an inevitable consequence of the stochastic nature of processes driving transcription and translation. While previous studies demonstrated that gene expression noise is negatively correlated with gene body methylation, the function of this correlation remains poorly understood in multicellular systems. Here, we provide a first functional link between gene body methylation and transcription noise in plants. We investigated a mutant with partial loss of CG methylation (met1-1) and 10 epigenetic recombinant inbred lines (epiRILs) generated by a cross between Col-0 and met1-3 plants, and observed an increase in gene expression noise, but this was not the case in met1-3 with complete loss of CG methylation. Loss of CG methylation in met1-3 could be compensated by a low but significant gain of non-CG methylation that buffers the noise in gene expression. Overall, our results show that gene body methylation has a functional role in reducing variability in transcription in a large subset of housekeeping genes, which require precise expression patterns to meet metabolic requirements. Genes lacking this noise-buffering effect are mainly enriched in stress response, where variability in gene expression can be seen as highly beneficial.
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mhryu@live.com
February 17, 10:36 AM
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Unconventional protein secretion (UcPS) enables the export of cytosolic proteins through pathways that bypass the canonical endoplasmic reticulum–Golgi secretory route. Although increasingly recognized as essential for intercellular communication, stress responses, and tissue homeostasis, UcPS remains difficult to quantify due to low secretion efficiency, high intracellular background, and the challenge of distinguishing active secretion from passive leakage. Recent methodological advances, including NanoLuc split luciferase–based reporters and the Retention Using Selective Hooks (RUSH) system for synchronized protein transport, have improved sensitivity and temporal control of trafficking. Here, we present complementary protocols integrating these tools to provide a highly sensitive, quantitative workflow centered on a split NanoLuc (HiBiT/LgBiT) complementation assay for monitoring UcPS in mammalian cells. The Basic Protocol describes a robust luminescence-based secretion assay, while the Support Protocols detail the generation of stable HiBiT reporter cell lines, approaches for probing UcPS mechanisms using siRNA-mediated gene knockdown and pharmacological perturbation, and the incorporation of the RUSH system to synchronize cargo release and identify potential trafficking intermediates. Together, these protocols provide a sensitive, scalable, high-throughput toolkit that enables analysis of UcPS mechanisms across diverse cargo proteins, cell types, and perturbations. This methodological framework allows for rigorous dissection of UcPS pathways in both physiological and disease-relevant contexts.
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RNA polymerase activity might be encoded by shorter RNA motifs.