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Genetically Engineered Microorganisms and Their Impact on Human Health

Genetically Engineered Microorganisms and Their Impact on Human Health | RMH | Scoop.it

The emergence of antibiotic-resistant strains, the decreased effectiveness of conventional therapies, and the side effects have led researchers to seek a safer, more cost-effective, patient-friendly, and effective method that does not develop antibiotic resistance. With progress in synthetic biology and genetic engineering, genetically engineered microorganisms effective in treatment, prophylaxis, drug delivery, and diagnosis have been developed. The present study reviews the types of genetically engineered bacteria and phages, their impacts on diseases, cancer, and metabolic and inflammatory disorders, the biosynthesis of these modified strains, the route of administration, and their effects on the environment. We conclude that genetically engineered microorganisms can be considered promising candidates for adjunctive treatment of diseases and cancers.

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Genetic improvement of nitrogen- and phosphorus-use efficiency in crops: Old goals with new aspirations | mpt

Genetic improvement of nitrogen- and phosphorus-use efficiency in crops: Old goals with new aspirations | mpt | RMH | Scoop.it
Nitrogen (N) and phosphorus (P) are indispensable macronutrients for crop growth and productivity; however, their excessive application in agriculture has caused severe environmental degradation. Enhancing crop N-use efficiency (NUE) and P-use efficiency (PUE) is a critical strategy to reconcile high productivity with sustainability. In this review, we systematically synthesize recent advances in the genetic basis of NUE and PUE in crops, focusing on key traits and their associated signaling networks. We summarize the identification of N/P-efficiency genes and explore how natural variations in these genes correlate with soil nutrient availability, revealing adaptive patterns from crop domestication. Given the distinct biogeochemical behaviors of N and P, we propose tailored strategies that leverage nutrient-specific traits to optimize environment–resource coordination and yield–quality balance. Finally, we discuss strategies for developing future crop cultivars with enhanced NUE or PUE to advance sustainable agriculture.
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Immune evasive DNA donors and recombinases license kilobase-scale writing | nat

Immune evasive DNA donors and recombinases license kilobase-scale writing | nat | RMH | Scoop.it

Genome-editing technologies that use recombinases to insert kilobase-scale DNA sequences into mammalian genomes canonically require large double-stranded DNA (dsDNA) donors. However, dsDNA molecules evoke problematic and toxic innate immune responses, limiting integration efficiencies and generally constraining applicability to ex vivo or immune-deficient contexts. By harnessing mechanisms of integrative prokaryotic viruses and mobile genetic elements, here we demonstrate that recombinases are compatible with immune evasive circular single-stranded DNA molecules optimally bearing a partial-duplex region that reconstitutes the recombinase recognition sequence. This approach, which we term integration through nucleus-synthesized template addition of large lengths (INSTALL), is compatible with diverse protein and RNA-guided recombinases for high-fidelity kilobase-scale human genome writing. INSTALL minimizes innate immune responses in primary human cells and in mice, improving recombinase-mediated integration efficiencies and supporting systemic in vivo non-viral DNA delivery by substantially increasing tolerability and broadening the dosing range compared with lipid nanoparticle-delivered dsDNA molecules. Together, INSTALL overcomes fundamental challenges for DNA delivery and integration methods by synergizing immune-stealth nucleic acids with recombinases to enable kilobase-scale integration strategies without viral vectors. INSTALL overcomes fundamental challenges for DNA delivery and integration methods by synergizing immune-stealth nucleic acids with recombinases to enable kilobase-scale integration strategies without viral vectors.

mhryu@live.com's insight:

a, INSTALL-1 uses cssDNA as a donor for recombination, which relies on priming and second-strand synthesis to form a dsDNA substrate. b, Annealing of a short PIP to a cssDNA molecule to create an oDNA. c, INSTALL-2 with oDNA permits immediate recognition of the cssDNA molecule by recombinases due to the reconstituted dsDNA binding region, enabling integration before second-strand synthesis and independent of primase.

pre-annealing a short DNA oligonucleotide, termed a partial-duplex integration polynucleotide (PIP), to the cssDNA to form an oligo-annealed cssDNA (oDNA) containing only a short dsDNA binding site for the recombinase 

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Next-generation programmable cell therapies for precision medicine | Nrg

Next-generation programmable cell therapies for precision medicine | Nrg | RMH | Scoop.it

Engineered cell therapies are transforming precision medicine by enabling real-time, context-responsive interventions that act upon disease-specific cues. Inspired by the success of CAR-T cells in oncology, next-generation platforms are being developed using diverse immune cells and stem cells to address a broader spectrum of diseases. These living therapeutics harness synthetic gene circuits to induce targeted cytotoxicity, to modulate the secretion of effector proteins or to coordinate both functions in response to endogenous signals or externally delivered molecular and physical triggers. Ex vivo engineering of autologous cells remains the norm, but challenges in scalability, cost and accessibility are fuelling efforts towards allogeneic products and in vivo reprogramming. Advances in targeted delivery — using viral vectors, mRNA-loaded nanoparticles and virus-like particles — are expanding the toolkit for direct programming of cells within the body. This Review discusses emerging strategies for engineering human cells with therapeutic functions, highlighting modular control systems, delivery innovations and the translational hurdles that lie ahead. In this Review, Teixeira et al. discuss emerging strategies for developing and improving engineered-cell therapies. They outline progress from ex vivo engineered autologous cells to in vivo reprogramming, advances in delivery systems and the remaining translational barriers.

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Fussenegger, fusseneger 

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Impacts of climate extremes on plant pathogens, microbiomes and plant health | Nrm

Impacts of climate extremes on plant pathogens, microbiomes and plant health | Nrm | RMH | Scoop.it

Plant diseases pose a great risk to global food security, and recent research indicates that pathogen pressures on plant productivity will substantially increase under ongoing climate change (that is, increasing CO2 levels and global warming). However, our mechanistic and predictive knowledge of the impacts of climate extremes, such as heatwaves and prolonged droughts, and their interaction with other climatic factors, on plant pathogens, hosts and microbiomes, remains largely unknown. This is an important knowledge gap that limits our ability to develop effective strategies to mitigate the socioeconomic impacts of climate change-induced plant disease outbreaks. This Review examines the impacts of key climate extremes on soil-borne pathogens, plant microbiomes and host physiology that ultimately determine disease outcomes. We explore evidence that suggests that the responses of pathogen–host–microbiome interactions to climate extremes may differ in many ways from those to long-term climate change. Climate extremes may increase the virulence and distribution of many pathogens, suppress certain plant immune responses, and weaken the core functions of host microbiomes within the disease triangle, thereby facilitating disease outbreaks. We propose an integrated pathway for harnessing microbiomes to address the critical challenges posed by climate extremes. These insights offer new approaches to mitigate disease risks by harnessing microbiomes and metabolites under climate extremes, with the potential to support climate-resilient and sustainable agricultural and natural ecosystems. In this Review, Singh BK and colleagues discuss the impacts of key climate extremes on soil-borne pathogens, plant microbiomes and host physiology that ultimately determine disease outcomes, as well as the eco-evolutionary mechanisms by which pathogens, hosts and microbiomes may adapt to climate extremes. Finally, they propose an integrated pathway for harnessing microbiomes to address the critical challenges posed by climate extremes.

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Targeting redundant gene families: A multiplexed, tissue-specific CRISPR toolbox for Arabidopsis genetic screens | Cin

Targeting redundant gene families: A multiplexed, tissue-specific CRISPR toolbox for Arabidopsis genetic screens | Cin | RMH | Scoop.it
Genome-scale targeted CRISPR libraries for forward genetic screens in plants are powerful tools for functional analysis, but they suffer from limited spatial control, single sgRNA design, and poor handling of genetic redundancy. We develop multiplexed CRISPR libraries in which each construct contains two sgRNAs that simultaneously target multiple members of a gene family. The libraries can also function at the cell-type-specific and tissue levels. A double-barcoding strategy enables efficient tracking and identification of sgRNA combinations at the plant level without individually sequencing each line. Using this platform, we generate over 1,000 Arabidopsis lines that express sgRNAs targeting 707 transporter genes across 114 gene families involved in nutrient uptake. The multiplexed design increases gene coverage and editing efficiency, underscoring its improved targeting capability to reveal hidden phenotypes. This toolbox provides a scalable resource for multi-targeted genome editing and spatially precise forward genetic screens in plants.
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Reverse vaccinology 3.0 | Nrm

Reverse vaccinology 3.0 | Nrm | RMH | Scoop.it

Artificial intelligence has rapidly entered the field of life sciences, including vaccine development. Here, we introduce ‘reverse vaccinology 3.0’, a transformative approach that could revolutionize the field of vaccinology and contribute to addressing global health challenges. Andreano, McLellan and Rappuoli introduce ‘reverse vaccinology 3.0’, a transformative approach that could revolutionize the field of vaccinology and contribute to addressing global health challenges.

mhryu@live.com's insight:

Starting with reverse vaccinology, genomic approaches can be used to sequence the whole genome of the targeted pathogen, and the sequences can be used to identify potential antigens. Using the reverse vaccinology 2.0 approach, we can perform antigen-agnostic single-cell sorting of memory B cells from infected or vaccinated individuals to identify neutralizing antibodies. The antibody and antigen sequences will be fed to artificial intelligence tools that can predict the targeted antigen on the pathogen surface. Structural biology will be used to confirm the artificial intelligence prediction and identify protective epitopes on the antigen surface. The obtained information can be used to accelerate the development of vaccines, monoclonal antibodies (mAbs) and new therapies. PBMC, peripheral blood mononuclear cell.

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De novo design of functional nucleic acids of aptamers | Ncs

De novo design of functional nucleic acids of aptamers | Ncs | RMH | Scoop.it

Functional nucleic acids (FNAs) are essential elements for designing advanced molecular tools, yet their de novo design faces challenges due to the vast sequence space and inefficiency of experimental screening methods. Nucleic acid large language models (NA-LLMs) offer new opportunities for FNA design, but their generative capability remains underexplored. Here we introduce InstructNA, a framework leveraging NA-LLMs and high-throughput systematic evolution of ligands by exponential enrichment (HT-SELEX) to guide de novo design of FNAs without relying on structural information. InstructNA encodes semantically rich FNA representations and robustly decodes FNA sequences, enabling the generation of various types of FNA such as transcription factor-binding DNA and protein-binding aptamers with enhanced functionality and high sequence diversity. Compared with the traditional HT-SELEX, InstructNA generates 100% and 200% more strong aptamer binders for two protein targets, with a sequence similarity to the original HT-SELEX aptamers as low as 38%. These results underscore the efficacy and robustness of InstructNA, demonstrating its potential for FNA design. InstructNA leverages nucleic acid large language models with HT-SELEX for de novo generation of functional nucleic acids, exhibiting high efficiency and general applicability in designing aptamers for various targets.

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Transcriptional interference revisited | Ngen

Transcriptional interference revisited | Ngen | RMH | Scoop.it

The transcriptional interference model suggests that RNA polymerases elongating through overlapping transcription units mutually inhibit transcription and disrupt associated cis-regulatory elements. As a longstanding fundamental concept of gene regulation, the idea of reciprocal inhibition between sense and antisense transcription has been supported by a significant body of research. However, despite the model’s biophysical plausibility and historical significance, evidence from large-scale transcriptome studies raises questions about its universal applicability. In particular, the new data indicate that a measurable influence of transcriptional interference is absent from the majority of loci with overlapping transcription. Here we highlight key aspects of overlapping transcription and propose potential solutions to this emerging puzzle. Gaining a better understanding of the molecular mechanisms that render loci sensitive or resistant to interference could lead to groundbreaking insights into the biology of gene regulation. The transcriptional interference model has been instrumental in shaping our understanding of gene regulation. However, given that its effects are largely absent from genome-wide data, this Perspective reexamines the underlying mechanisms and suggests how they may be resolved at most loci.

mhryu@live.com's insight:

This interference is believed to occur through various mechanisms, including RNA polymerase collisions, promoter occlusion and the dislodgement of transcription factors.  While the biophysical basis for transcriptional interference is plausible, its functional impact appears to be limited and context dependent

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Mechanisms of thermoregulation in Pseudomonas aeruginosa | jbac

Mechanisms of thermoregulation in Pseudomonas aeruginosa | jbac | RMH | Scoop.it
Pseudomonas aeruginosa is a highly versatile opportunistic pathogen and a major cause of acute, chronic, and even lifelong respiratory infections in people with cystic fibrosis. It can also cause corneal infections, burn/wound infections, and bacteremia. P. aeruginosa is often found in human-associated environments such as hospitals, where it is a frequent cause of nosocomial catheter-associated urinary tract infections and ventilator-associated pneumonia. As a nosocomial pathogen, a major environmental change associated with transmission is the change from room or ambient temperature to human body temperatureP. aeruginosa is highly studied for its regulatory and adaptive responses to environmental stimuli, such as low iron conditions or the presence of antibiotics, but temperature regulation, or thermoregulation, is relatively understudied, particularly at a mechanistic level. This review explores the current understanding of mechanisms of global, transcriptional, post-transcriptional, and post-translational thermoregulation in P. aeruginosa, with a discussion on gaps in the field’s knowledge and directions for future research. More mechanistic studies of thermoregulation inspired by the open questions presented here will improve our understanding of how P. aeruginosa adapts to different temperatures.
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Discovery of de novo peptides by mRNA and RaPID displays with post-translational modification methods | Cin

Discovery of de novo peptides by mRNA and RaPID displays with post-translational modification methods | Cin | RMH | Scoop.it
Peptides have emerged as promising therapeutic agents due to their high target specificity and low toxicity. Recent advances in technologies for de novo peptide discovery have positioned them as attractive candidates for drug development. Among the leading platforms for screening large peptide libraries, mRNA display stands out for its unparalleled library size (>10¹² unique sequences) and its compatibility with genetic code reprogramming, enabling the generation of natural product-like peptides. However, the dependence on ribosomal translation and specific acyl-tRNAs imposes significant constraints on the accessible chemical space. This review highlights strategies that employ post-translational modifications (PTMs) to overcome these limitations, thereby greatly expanding peptide structural diversity. The successful identification of potent pseudo-natural product peptides through integrated PTM–mRNA display systems underscores the therapeutic potential of this approach.
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Functional customization of peptide linkers in fusion proteins through multimodal deep learning approach | ssb

Functional customization of peptide linkers in fusion proteins through multimodal deep learning approach | ssb | RMH | Scoop.it
Peptide linkers are critical modulators of function in fusion proteins, a foundational technology in modern bioengineering. However, the rational customization of linkers for specific applications remains challenging, hindered by an insufficient understanding of the relationship between linker sequences and fused protein function. In this study, we systematically characterized 370 diverse linkers, generated from random 18–amino acid sequences with no homology to known proteins, fusing sfGFP to a nanobody. Although sfGFP fluorescence exhibited no clear correlation with canonical linker properties like flexibility or rigidity, we identified a correlation between amino acid composition and functional output. Furthermore, AlphaFold-predicted substructures encompassing the linker and adjacent sfGFP regions revealed considerable structural diversity while maintaining the overall sfGFP fold. Notably, in silico structural features derived from the Cα–Cα distance matrix of these predicted substructures correlated with fluorescence, providing a structural rationale for the functional variation. By training on both sequence representations and in silico substructural features, we developed a multimodal deep learning framework to quantitatively customize linker sequences for high sfGFP fluorescence in special fusion constructs. This work presents a generalizable framework for engineering peptide linkers to assemble highly functional fusion proteins.
mhryu@live.com's insight:

linker optimization

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Active removal of inhibitory components drives the flagellar Type III Secretion Specificity Switch | brvm

Active removal of inhibitory components drives the flagellar Type III Secretion Specificity Switch | brvm | RMH | Scoop.it

Type III secretion (T3SS) systems assemble bacterial nanomachines, including the flagellum and virulence-associated injectisomes, by exporting distinct classes of substrates in a defined temporal order. In both systems, completion of an early assembly intermediate triggers an irreversible switch from early to late substrate secretion. In the flagellar system, this switch is controlled by the secreted molecular ruler FliK acting on the core T3S component FlhB, but the molecular mechanism governing this transition has remained unclear. Here we show that removal of two components, Fluke and the cleaved C-terminal domain of FlhB (FlhBCCD), locks the secretion apparatus in a constitutive late secretion state. In these mutants, secretion specificity no longer requires completion of the hook-basal body or the FliK ruler, indicating that Fluke and FlhBCCD function to maintain the apparatus in early secretion mode. Consistent with this model, synchronized flagellar gene expression experiments reveal that FlhBCCD is retained during early assembly and is lost coincident with hook-basal body completion and activation of σ28-dependent late gene expression of flagellin and chemosensory genes. Structural modeling of the FliK C-terminal switch domain and FlhBCCD supports a mechanism in which secretion of FliK promotes destabilization and ejection of FlhBCCD from the secretion apparatus. Disruption of a folded region within FliK switch domain uncouples secretion from switching, indicating that the timing of FliK unfolding during secretion is critical for activation of the specificity switch. These findings show that secretion specificity switching is driven by FliK-dependent removal of inhibitory components, rather than passive sensing of assembly completion.

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Biophysics-informed design of biohybrid microrobots | Nrb

Biophysics-informed design of biohybrid microrobots | Nrb | RMH | Scoop.it

Biohybrid microrobots integrate biological components with synthetic structures to navigate complex biological environments, for example, for the delivery of drugs, microsurgery and in vivo diagnostics. In this Review, we propose a biophysics-informed design framework for biohybrid microrobots by connecting biophysical principles with biohybrid solutions. We first identify the biophysical constraints imposed by the human body that limit microrobot integrity, locomotion, navigation and functionality. We then examine the biophysical mechanisms through which biological cells, microorganisms and their derivatives adapt to these challenges, and explore how these can be utilized to improve the performance of microrobots. Building on these insights, we describe how biohybrid microrobots translate biophysical strategies into engineering solutions across four design domains: deformation, actuation, navigation and programming. Finally, we discuss persisting in vivo challenges, key considerations for clinical translation and future developments. By articulating design logics that span biological and synthetic domains, this framework provides a functional definition of biohybrid microrobots and offers a shared language for researchers across disciplines. Biohybrid microrobots combine biological and synthetic components to navigate complex in vivo environments for applications such as drug delivery, microsurgery and diagnostics. This Review introduces a biophysics-informed design framework for biohybrid microrobots that translates natural adaptive strategies into engineering solutions across deformation, actuation, navigation and programming.

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Engineering Aspergillus oryzae for enhanced heterologous protein production by synthetic biology toolkit development and morphology control

Engineering Aspergillus oryzae for enhanced heterologous protein production by synthetic biology toolkit development and morphology control | RMH | Scoop.it
To address the low efficiency of genetic manipulation and poor hyphal morphology control in Aspergillus oryzae, this study developed a synthetic biology toolkit and identified a key genetic target for morphological engineering. The toolkit features an RNP-mediated rapid knockout system, serine integrase-based gene integration, and a pipeline for screening high-activity neutral genomic sites. Systematic deletion of seven cell wall integrity-related genes revealed that disruption of the chitin synthase gene chsY most effectively enhanced protein secretion. The ΔchsY mutant exhibited a 34.8 % increase in hyphal diameter and a 30.6 % reduction in culture viscosity, coupled with upregulated secretory pathways and an activated unfolded protein response (UPR). Applying this discovery, we engineered a strain expressing a heterologous lipase (TLL), achieving a 52 % increase in extracellular activity in flasks. This benefit scaled to bioreactors, with a 42 % higher enzyme titer and ∼50 % lower viscosity. Our work provides both a genetic toolkit and a scalable engineering strategy (chsY deletion) to enhance A. oryzae as a cell factory for industrial enzyme production.
mhryu@live.com's insight:

bck1 knockout exhibited remarkably enhanced extracellular protease secretion on skim milk plates. Although colony diameter was reduced, it produced substantially larger hydrolysis halos

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FuzDrop: sequence-based prediction of the propensity of proteins for liquid–liquid phase separation and aggregation | Npc

FuzDrop: sequence-based prediction of the propensity of proteins for liquid–liquid phase separation and aggregation | Npc | RMH | Scoop.it

Proteins exhibit complex phase behavior as they convert between the native state, the liquid condensate (or droplet) state and the solid condensate (or amyloid) state. To facilitate the study of these processes, we describe the FuzDrop method of predicting the condensation propensity of proteins to undergo liquid–liquid phase separation and to subsequently form amyloid aggregates. The method is based on the principle that liquid condensations reflect a balance between enthalpic and entropic contributions; FuzPred is an algorithm that provides sequence-based estimates for these contributions in stoichiometric complexes ( https://fuzpred.bio.unipd.it/predictor ). FuzDrop extends this algorithm to protein condensates, and enables prediction of the propensity for amyloid formation within liquid condensates, known as the condensation pathway to protein aggregation ( https://fuzdrop.bio.unipd.it/predictor ). This prediction is based on the principle that the sequence regions that promote aggregation within liquid condensates have a multiplicity of binding modes, because they have a strong propensity for both entropic-driven interactions to stabilize the droplet state and enthalpic-driven interactions to stabilize the amyloid state. The time required for FuzDrop predictions on the web server scales linearly with protein length and is typically ~30 s for a protein of 500 residues. By enabling predictions of protein phase behavior, FuzDrop may facilitate experimental studies directed at the development of therapies for protein condensation diseases. FuzDrop predicts the condensation propensity of proteins on the basis of their amino acid sequences. This protocol describes the underlying theory and how to use the results to understand liquid-liquid phase separation and amyloid aggregate formation.

mhryu@live.com's insight:

2st, llps

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Capturing dynamic phage–pathogen coevolution by clinical surveillance | nat

Capturing dynamic phage–pathogen coevolution by clinical surveillance | nat | RMH | Scoop.it

Bacteria harness diverse defence systems that protect against phage predation, many of which are encoded on horizontally transmitted mobile genetic elements. In turn, phages evolve counter-defences, driving a dynamic arms race that remains underexplored in human disease contexts. For the diarrhoeal pathogen Vibrio cholerae, a higher burden of its lytic phage ICP1 in patient stool correlates with reduced disease severity. However, direct molecular evidence of lytic phages driving selection of epidemic V. cholerae has not been demonstrated. Here, through clinical surveillance in cholera-endemic Bangladesh, we capture the acquisition of a parasitic antiphage mobile genetic element, PLE11, that initiated a selective sweep coinciding with the largest cholera outbreak in recent records. PLE11 showed potent anti-phage activity against cocirculating ICP1, explaining its rapid and dominating emergence. We identify PLE11-encoded Rta as the defence responsible and provide evidence that Rta restricts phage tail assembly. Using experimental evolution, we predict phage counteradaptations against PLE11 and document the eventual emergence and selection of clinical ICP1 that achieve a convergent evolutionary outcome. Finally, we discover how PLEs balance their dependence on ICP1 tail proteins for horizontal transmission with the restriction of phage tail assembly by Rta: PLEs construct chimeric tails composed of both mobile genetic element-encoded and phage-encoded proteins to ensure their transmission. Collectively, our findings reveal the molecular basis of the natural selection of a globally important pathogen and its virus in a clinically relevant context. The acquisition of a parasitic anti-phage mobile genetic element, PLE11, showing potent anti-phage activity against cocirculating ICP1, and the subsequent evolution of ICP1 to escape this defense, are captured, revealing the molecular basis of the natural selection of a globally notable pathogen and its virus.

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A combined strategy for high-efficiency expression of alkaline protease PrtA in Komagataella phaffii (syn. Pichia pastoris) | Mcf

A combined strategy for high-efficiency expression of alkaline protease PrtA in Komagataella phaffii (syn. Pichia pastoris) | Mcf | RMH | Scoop.it

Microbial serine proteases are valuable for industrial applications due to broad substrate specificity and stability. However, heterologous overexpression in microbial hosts is often limited by cytotoxicity and poor secretion. This study developed an integrated strategy combining protein engineering and signal peptide optimization to enhance extracellular production of PrtAa key acid-stable alkaline serine protease—in Komagataella phaffii.  Directed evolution generated the Q245K variant, showing 1.35-fold higher extracellular expression than wild-type PrtA. A machine learning model, MPEPE (Mutation Predictor for Enhanced Protein Expression), was used to identify critical residues involved in protein secretion; saturation mutagenesis at the top-predicted site generated the I342D mutant with 1.48-fold improved productivity. The double mutant PrtA-Q245K/I342D achieved synergistic enhancement (1.84-fold higher secretion) without altering enzymatic properties. Evaluation of nine signal peptides revealed that serum albumin, α-factor (without pro-region), and PrtA’s native signal peptides each doubled the combinatorial mutant’s secretion, yielding 4.98-fold higher expression than the wild-type. In contrast, α-factor pro-region inclusion drastically reduced yields. In a 15-L fed-batch bioreactor, the optimized strain produced PrtA-Q245K/I342D at 4807.5 U/mL, equivalent to 1.5 g/L protein.  The combined approach of directed evolution, machine learning-guided mutagenesis, and signal peptide engineering significantly boosted PrtA secretion while maintaining functional integrity. This strategy demonstrates strong potential for scalable industrial production of challenging heterologous proteases.

mhryu@live.com's insight:

Based on screening the hydrolysis zone on milk agar plates

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Microbial diversity as a foundation for biological AI | EMBO

Microbial diversity as a foundation for biological AI | EMBO | RMH | Scoop.it

We therefore propose microbes as simple and scalable model systems to represent a cell that has evolved under selective pressures to adapt to its environment and discuss how microbial genetic diversity can help to improve the performance and benefits of AI models. We argue that, with the help of AI, microbial sequence data from across our planet’s diverse environments can be used to address fundamental biological questions, such as evolution and adaption, how cells make decisions, the relationships and communication between organisms, and how emergent properties arise in biological systems. It would require multi-modal AI models that, in addition to sequence data, also incorporate additional ‘languages’ on environmental and evolutionary processes beyond linear DNA sequences.

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Cross-kingdom RNA interference promotes arbuscular mycorrhiza development | Npt

Cross-kingdom RNA interference promotes arbuscular mycorrhiza development | Npt | RMH | Scoop.it

Cross-kingdom RNA interference is an emerging concept in plant–pathogen interactions. Here we provide evidence that cross-kingdom RNA interference also occurs in a beneficial plant symbiosis called arbuscular mycorrhiza AMF. The arbuscular mycorrhizal fungus Rhizophagus irregularis transfers small RNAs into plant cells, promoting the colonization of host roots. This finding establishes inter-organismal RNA communication as a new regulatory mechanism of this ancient and widespread symbiosis. The authors provide evidence that symbiotic fungi forming widespread arbuscular mycorrhiza symbioses use cross-kingdom RNA interference to silence plant genes and promote their colonization of host roots.

mhryu@live.com's insight:

2st

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Engineered TnpB genome editors for plants and human cells identified by ribonucleoprotein mutational scanning | Nbt

Engineered TnpB genome editors for plants and human cells identified by ribonucleoprotein mutational scanning | Nbt | RMH | Scoop.it

TnpB is a diverse family of RNA-guided endonucleases associated with prokaryotic transposons. Because of their small size and putative evolutionary relationship to CRISPR–Cas12, TnpB enzymes hold great potential for genome editing. However, most TnpBs lack robust gene-editing activity. Here, we mapped comprehensive sequence–function landscapes of a TnpB ribonucleoprotein using deep mutational scanning and we discovered activating mutations in both the RNA and the protein. Leveraging the protein’s mutational landscape, we constructed a combinatorial library of activating mutations, from which we identified two enhanced TnpB variants. These variants increased editing in human cells, Nicotania benthamiana, pepper and rice. While editing efficiencies varied by target site, engineered variants achieved up to 55% insertion and deletion frequencies (a 50-fold increase over wild type) in N. benthamiana, surpassing ISYmu1 (<7%), AsCas12f-HKRA (<9%) and other compact editors. These findings highlight elements critical for regulating TnpB endonuclease activity and demonstrate latent activity accessible through mutation. TnpB endonucleases are engineered for improved genome editing.

mhryu@live.com's insight:

savage df, doudna, 2st, methods for Combinatorial mutations: Using nicking mutagenesis, we generated a library of ~5 × 103 variants with an average of ~5 of the 33 possible mutations per variant

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Advance Microbiota Transplantation: A Novel Addition–Subtraction Paradigm for Optimising Faecal Microbiota Transplantation | mbt

Faecal microbiota transplantation (FMT) is highly effective for recurrent Clostridioides difficile infection but yields inconsistent benefits in chronic indications. As a crude whole-microbiota transplant, FMT contains numerous undefined active components, complicating efforts to ensure treatment predictability and stability. Therefore, we propose Advance Microbiota Transplantation (AMT), a comprehensive, phase-based hypothesis that employs an addition–subtraction strategy throughout the pre-, peri- and post-transplant stages. AMT comprises donor and recipient pre-treatment, procedural optimization and post-transplant adjuvant interventions to mitigate donor variability, ecological resistance, procedural heterogeneity and unstable engraftment. Through a systematic synthesis of current evidence-based FMT research, we explored how the addition–subtraction strategy can be operationalised to shape the AMT concept and define testable, phase-specific levers, thereby providing a foundation for future clinical translation. In parallel, we appraised the reporting quality using the Preferred Reporting Items for Microbiotherapy (PRIM) and identified six persistently under-reported items that limit the interpretability, comparability, and reproducibility of FMT research. This review aims to facilitate the integration of AMT into clinical practice.

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The interplay between temperature and growth phase shapes the transcriptional landscape of Pseudomonas aeruginosa | jbac

The interplay between temperature and growth phase shapes the transcriptional landscape of Pseudomonas aeruginosa | jbac | RMH | Scoop.it
Pseudomonas aeruginosa is a highly versatile bacterium capable of surviving and often thriving in stressful environmental conditions. Here, we report the effect of two environmental conditions, temperature and growth phase, on the P. aeruginosa PAO1 transcriptome. As P. aeruginosa is well-known for its growth phase dependent phenotypes and gene regulation, our goal was to determine how temperature altered global gene expression at exponential versus stationary phase and to characterize how growth phase affects thermoregulation. To do this, we grew PAO1 in parallel at 25°C and 37°C and sampled the same populations first at exponential phase and then again at stationary phase and assessed gene expression by RNA-sequencing. We found that temperature regulated hundreds of genes at, and unique to, exponential and stationary phases. We also grew PAO1 and an isogenic ΔlasR mutant at 25°C and 37°C and sampled populations at stationary phase to define LasR-regulated genes at each temperature by RNA-sequencing. LasR regulated most of its target genes similarly at 25°C and 37°C, although we identified a subset of genes whose regulation by LasR was affected by temperature. This work provides a comprehensive assessment of thermoregulation for PAO1 at two distinct growth phases, as well as growth phase transcriptomics at two temperatures, and expands our understanding of quorum sensing regulation under different environmental conditions that P. aeruginosa encounters.
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Yeast species resource exploration and application in cell factories | ssb

Yeast species resource exploration and application in cell factories | ssb | RMH | Scoop.it
Yeasts serve as important industrial hosts, contributing significantly to sustainable and green biomanufacturing efforts in the pursuit of global carbon neutrality, alongside other vital microorganisms. This review systematically summarizes recent advances in yeast cell factories, focusing on the exploration of yeast species resources, innovation in enabling technologies, and efficient biosynthesis strategies. The characteristics and industrial applications of commonly used industrial yeast chassis were reviewed. The advent of synthetic and systems biology tools has resulted in a significant enhancement of the efficiency of yeast manipulation and regulation. Key strategies for enhancing the titter, yield, and productivity (TRY) of yeast cell factories are elaborated, including dynamic regulation of metabolic pathways, transcription factor engineering for global metabolic regulation, GEM-driven optimization, dynamic trade-off between growth and production, and cofactor engineering for redox and energy balance. In the future, yeast cell factories will advance green biomanufacturing by leveraging AI-guided design and dynamic metabolic control to utilize C1 and recalcitrant carbon sources with high efficiency.
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mCSM-metal: A Deep Learning Resource to Predict Effect of Mutations on Metal Ion Binding | jmb

mCSM-metal: A Deep Learning Resource to Predict Effect of Mutations on Metal Ion Binding | jmb | RMH | Scoop.it
Metal ions play critical structural, regulatory, and enzymatic roles in proteins, making their binding essential for biological processes. Experimental identification of metal-binding sites is resource-intensive and limited in scalability. Recent advances in protein language models have transformed computational predictions, yet current tools do not address how residue-level metal-binding probabilities change upon mutation. To fill this gap, mCSM-metal leverages embeddings from ESMBind with our graph-based structural signatures to accurately predict the effects of single or multiple point mutations on the binding of seven essential ions (Zn2+, Ca2+, Mg2+, Mn2+, Fe3+, Co2+, Cu2+). Our model achieves accuracies, F1-scores, and Matthews Correlation Coefficient values up to 0.97, 0.97, and 0.95, outperforming other approaches. The webserver provides an interactive platform to assess and visualize local and long-range impacts of mutations on metal-ion binding, offering new avenues for applications in structural biology, disease modelling, and protein engineering. The web application is freely available at: https://biosig.lab.uq.edu.au/mcsm_metal/.
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Roles of microbial interactions in determining the establishment and function of synthetic consortium inoculants for soil applications | isme

Roles of microbial interactions in determining the establishment and function of synthetic consortium inoculants for soil applications | isme | RMH | Scoop.it

Synthetic microbial consortium inoculants are emerging nature-based solutions for promoting sustainable agriculture and mitigating environmental challenges. However, despite promising results in simpler lab-scale trials, many inoculants fail to establish or perform satisfactorily in field conditions. One most critical yet least understood factor influencing inoculant effectiveness is the complex microbial interactions, both within consortium inoculants (“within-community” interactions) and between consortium inoculants and native soil communities (“cross-community” interactions). Here, we first discuss major negative and positive “within-community” interactions and highlight the importance to design consortium inoculants with positive interactions for improved stability and functionality. We then examine the bidirectional “cross-community” interactions once introducing consortium inoculants to soils. Soil native communities often create strong resistance to the invasion of inoculants. We discuss major drivers controlling the invasibility of native communities and various strategies increasing the invasiveness of consortium inoculants. We then discuss how consortium inoculants can reshape native communities, with implications for long-term ecosystem resilience and functioning. We propose future research efforts including advancing strategies for harnessing natural species from relatively untapped soil reservoirs and using high-throughput interaction profiling with computational tools to build compatible synthetic consortia with desirable functions; leveraging positive interactions and prebiotics to facilitate inoculant establishment; and assessing fully soil functional resilience over longer terms, including recognizing the importance of rare keystone taxa. By integrating with ecological theory, this review provides a comprehensive insight into microbial interactions to advance the design, application, and monitoring of synthetic consortium inoculants for enhancing soil health and ecosystem sustainability.

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