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At least 19 recordsLinked to original sources
PubMed2026

A CRISPR-Cas9 screen identifies LAPTM4A (lysosomal protein transmembrane 4 alpha) as a key host barrier against PRRSV infection.

Porcine reproductive and respiratory syndrome virus (PRRSV) manipulates host intracellular processes, particularly macroautophagy/autophagy and lysosomal function, to facilitate its replication and spread. However, the precise host factors and molecular mechanisms by which PRRSV remodels the autophagy-lysosome axis remain poorly defined. Here, we performed a CRISPR-Cas9 knockout screen targeting 1,332 genes involved in protein degradation, metabolism, and vesicular trafficking, and identified LAPTM4A (lysosomal protein transmembrane 4 alpha) as a critical antiviral factor involved in the lysosomal pathway. A yeast two-hybrid screen identified LAPTM4A as an interactor of PRRSV GP5 (glycoprotein 5). Mechanistically, GP5 recruits the E3 ubiquitin ligase NEDD4 and the autophagy receptor SQSTM1/p62 to promote K63-linked polyubiquitination of LAPTM4A, leading to its autophagic degradation. This selective degradation activates the AMPK-ULK1-MAP1LC3/LC3 signaling cascade, initiating autophagy while facilitating MTOR-lysosome colocalization, thereby suppressing TFEB nuclear translocation and transcription of lysosome-related genes. The resulting incomplete autophagic flux enhances viral replication. Additionally, in terms of host defense, LAPTM4A maintains lysosomal homeostasis by restraining excessive autophagy through AMPK-ULK1-LC3 signaling and promoting TFEB-dependent lysosomal gene expression by impairing the binding of RPTOR/raptor to MTOR, thus providing broad antiviral protection against multiple RNA viruses. Collectively, our findings identify LAPTM4A as a central regulator of lysosome-autophagy homeostasis and reveal a viral strategy that dismantles this defense axis to facilitate infection.Abbreviations: ATG5: autophagy related 5; AMPK: adenosine 5'-monophosphate (AMP)-activated protein kinase; Baf A1: bafilomycin A1; CHX: cycloheximide; Co-IP: co-immunoprecipitation; DMVT library: protein degradation, metabolism, and vesicular trafficking library; LAPTM4A: lysosomal protein transmembrane 4 alpha; MAGeCK: model-based analysis of genome-wide CRISPR-Cas9 knockout; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; NC: negative control; PAMs: porcine alveolar macrophages; PRKAA/AMPKα: protein kinase AMP-activated catalytic subunit alpha; PRRSV: porcine reproductive and respiratory syndrome virus; qRT-PCR: quantitative real-time PCR; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TCID50: 50% tissue culture infective dose; TFEB: transcription factor EB; Ub: ubiquitin; ULK1: unc-51 like autophagy activating kinase 1; WT: wild type.

Animals↗
PubMed2026

YIPFα1A expression is regulated by multilayered molecular mechanisms.

Yip domain family (YIPF) proteins are five-pass transmembrane proteins that localize primarily to the Golgi apparatus. These proteins assemble into higher-order complexes with each α-subunit pairing specifically with a β-subunit to form a dimer which then assemble into complexes with two to four dimers. Notably, β-subunit expression depends on the corresponding α-subunit partner, and conventional transient overexpression of α-subunits has been extremely inefficient, hindering deeper analysis of YIPF complexes. To identify the cause of poor exogenous expression, we examined YIPF gene features and found two properties correlated with low expression: (i) rare-codon enrichment in the CDS and (ii) extended 3' UTRs. Experimental analyses focusing on YIPFα1A revealed that rare-codon enrichment suppresses expression mainly at the mRNA level, consistent with translation-coupled mRNA decay, whereas inclusion of the native 3' UTR enhances expression by increasing mRNA abundance. Deletion mapping further showed that a proximal 3' UTR segment (51-150) is necessary and sufficient for mRNA stabilization, thereby elevating both mRNA and protein levels. Conversely, a distal 3' UTR fragment (1116-2230) increased mRNA but not protein levels, suggesting translational repression resulting in a reduced protein-to-mRNA ratio. Together, these findings explain the discrepancy between endogenous and exogenous YIPFα1A expression and propose a multilayered regulatory model in which rare codons decrease mRNA, the proximal 3' UTR stabilizes mRNA, and the distal 3' UTR reduces translation. Impact statement Our work advances YIPF biology and identifies post‑transcriptional mechanisms governing multi‑pass membrane proteins. We show rare‑codon and 3' UTR‑based control of trafficking proteins-an area largely unexplored-and introduce a new paradigm for membrane‑traffic regulation that will guide future studies of complex assembly, localization, and homeostasis.

3' Untranslated Regions↗
PubMed2026

Dysregulated Ribonucleoprotein Granules Impair Mitochondrial Function in RBM20-Related Dilated Cardiomyopathy.

BACKGROUND: Pathogenic variants in RBM20 cause severe dilated cardiomyopathy. Loss-of-function variants disrupt splicing; neomorphic gain-of-function (GoF) variants also mislocalize RBM20 to cytoplasmic ribonucleoprotein granules and are associated with more aggressive disease. The mechanism by which RBM20 mislocalization drives cardiac dysfunction remains unknown. METHODS: We investigated the effects of Rbm20 GoF and loss-of-function (LoF) variants using proteomic profiling, protein solubility assays, mitochondrial respiration and calcium flux analyses, and ultrastructural imaging in mouse models. Human induced pluripotent stem cell-derived cardioids were used to validate variant-specific phenotypes. RESULTS: Rbm20 GoF, but not LoF, variants caused posttranscriptional downregulation of soluble mitochondrial proteins, including the calcium efflux regulator TMEM65 (transmembrane protein 65), and reduced solubility of mitochondrial membrane proteins. Electron microscopy revealed enlarged mitochondria with cristae disorganization. Functional assays confirmed impaired oxidative phosphorylation, reduced mitochondrial membrane potential, and abnormal calcium handling in Rbm20 GoF models. Human cardioids reproduced these findings, demonstrating that cytoplasmic mislocalization, rather than splicing deficiency, drives mitochondrial dysfunction. CONCLUSIONS: Cytoplasmic mislocalization of RBM20 disrupts mitochondrial function by reducing mitochondrial protein abundance, leading to oxidative phosphorylation failure and abnormal mitochondrial calcium handling. This mechanism distinguishes RBM20 GoF from LoF variants and may explain the more severe heart failure phenotype observed in patients with RBM20 GoF variants. These insights advance the mechanistic understanding of RBM20-related cardiomyopathy and identify mitochondrial mRNA/protein regulation as a key node in cardiac energetics.

cardiomyopathy, dilated↗
PubMed2026

Molecular Pathogenesis, Global Epidemiological Trends, and Treatment Strategies for Pteropine Orthoreoviruses: A Narrative Review.

Pteropine orthoreoviruses are emerging bat-borne zoonotic viruses of the genus Orthoreovirus (family Reoviridae), increasingly recognized as causes of acute respiratory disease in humans. Originally grouped with the largely non-pathogenic mammalian orthoreoviruses, they have challenged that view through their association with severe influenza-like illness, evidence of human-to-human transmission, and a broad geographic range across the Old World. Maintained primarily in fruit bats of the family Pteropodidae, they are now linked to neurological as well as respiratory disease. This narrative review synthesizes current knowledge of their molecular pathogenesis, zoonotic ecology, and global epidemiology, integrating recent advances in phylogeography, reassortment-driven evolution, spillover dynamics, and translational biomedical applications within a unified One Health framework. Genomic diversity, reassortment potential, and the unique fusion-associated small transmembrane proteins together underpin viral adaptability and pathogenicity. Major gaps nonetheless remain in transmission dynamics, host adaptation, shedding ecology, and pandemic potential. Future priorities should include integrated genomic surveillance, improved diagnostic strategies, validated experimental models, and interdisciplinary One Health approaches to strengthen outbreak preparedness and prevention.

Bat-borne viruses↗
PubMed2025

Development of a plant-based vaccine against brucellosis: stable expression of Brucella abortus OMP25 in transgenic tobacco.

Brucellosis, caused by Brucella species, is a global threat to livestock farming, resulting in economic losses and socio-economic challenges, particularly in rural areas. Despite its impact, no licensed human vaccines are available. Animal vaccination remains the most cost-effective control method, but traditional vaccine production is expensive. Edible vaccines, using plants as bioreactors to produce immunogenic antigens, offer a low-cost alternative by eliminating complex purification processes. This study developed a transgenic plant by expressing the Brucella abortus outer membrane protein OMP25 in tobacco plants. OMP25, a conserved transmembrane protein with high immunogenicity, was cloned into a Gateway pDONR vector via a Boundary Pairing reaction and transferred to a binary destination vector via a Left-Right reaction. The destination vector was introduced into Agrobacterium tumefaciens and subsequently used for Agrobacterium-mediated transformation of tobacco plants. Transgenic plants were selected on media containing kanamycin, and the expression of the transgene was verified through the fluorescence of green fluorescent protein. Microcallus formation and shoot development on selective media confirmed kanamycin resistance and the successful integration of the transgene. After phenotypic selection, genomic DNA was extracted from transgenic plants and analyzed by PCR (Polymerase Chain Reaction) using primers specific to the OMP25 gene. Positive PCR results validated the successful integration of the OMP25 gene into the plant genome. Gene expression was further confirmed at the RNA level through real-time quantitative PCR (qRT-PCR) and at the protein level via Western blot analysis. Future studies will evaluate immune responses in animal models. This approach demonstrates the potential for low-cost, effective vaccines to combat brucellosis, addressing critical economic and public health challenges.

Plants, Genetically Modified↗
PubMed2026

CRISPR/Cas9 loss-of-function screen in a neuronal model of AP-4 deficiency identifies ATG9A trafficking modulators.

Biallelic loss-of-function variants in adaptor protein complex 4 (AP-4) disrupt trafficking of transmembrane proteins at the trans-Golgi network, including autophagy-related protein 9A (ATG9A), leading to childhood-onset hereditary spastic paraplegia (AP-4-HSP). AP-4-HSP is characterized by features of both a neurodevelopmental and a degenerative neurological disease. To investigate the molecular mechanisms underlying AP-4-HSP and identify potential therapeutic targets, we conducted an arrayed CRISPR/Cas9 loss-of-function screen of 8,478 genes, targeting the "druggable genome," in a human neuronal model of AP-4 deficiency. Through this phenotypic screen and subsequent experiments, key modulators of ATG9A trafficking were identified, and complementary pathway analyses provided insights into the regulatory landscape of ATG9A transport. Knockdown of ANPEP and NPM1 enhanced ATG9A availability outside the trans-Golgi network, suggesting that they regulate ATG9A localization. These findings deepen our understanding of ATG9A trafficking in the context of AP-4 deficiency and offer a framework for the development of targeted interventions for AP-4-HSP.

Humans↗
PubMed2026

Proteomic analysis of ammonia-induced stress in Chinese hamster ovary (CHO) cell cultures.

Ammonia (NH₃) and its ionic form ammonium (NH₄+) are both metabolic waste products and essential nitrogen sources within Chinese hamster ovary (CHO) cell cultures. Although necessary for amino acid synthesis, excessive accumulation in the extracellular environment can exert stress, reducing cell proliferation and impairing the efficiency of recombinant protein production. Proper endoplasmic reticulum (ER) function is critical for CHO cells as biotherapeutic producers. Previous work has linked elevated ammonia concentrations to reduced productivity via altered N-glycosylation pathways, but its broader effects on ER biology remain unclear. In this study, we applied high-resolution mass spectrometry to perform a comprehensive analysis of changes in the ER proteome in CHO cells exposed to two ammonia concentrations, 10 mM and 30 mM, 48 and 120 h after supplementation. Both conditions suppressed cell growth and reduced product titre; however, the 10 mM supplementation resulted in a minor increase in specific cell productivity. Gene Ontology analysis revealed that ammonia strongly affected the tricarboxylic acid cycle, as well as key metabolic, catabolic and biogenetic processes. Several ER membrane proteins, including HMGCR and PREB, were consistently downregulated. In extended cultures, transmembrane proteins linked to Golgi-transport were upregulated, while vesicle transport associated proteins were downregulated, indicating altered intracellular trafficking. SIGNIFICANCE: This study provides a novel perspective on CHO cell biology under environmental stress by investigating the impact of ammonia accumulation in culture. Despite its presence in CHO culture, ammonia has been relatively under-investigated, compared to other culture conditions. Using high-throughput mass spectrometry for comprehensive proteomic profiling, we characterise the cellular response to ammonia build-up with a level of depth not previously applied to the study of this biological stressor. By specifically analysing proteins localised to the ER, we identify candidate pathways and molecular mechanisms that contribute to reduced CHO cell growth and productivity, offering insights directly relevant to industrial bioprocessing conditions. The link between ammonia concentration and a decrease in productivity has previously been linked to genes involved in N-glycosylation of the recombinant biotherapeutic, but the full extent of ammonia stress on ER function has not yet been investigated. These methods were applied to two IgG producing CHO cell lines to allow for comparison of cell line specific stress adaptations, as well as comparing the short- and long-term effects of excess ammonia.

Proteomics↗
PubMed2026

A conserved antioxidant defense at the endoplasmic reticulum membrane.

Oxidative protein folding in the endoplasmic reticulum (ER) is essential for eukaryotic cells yet generates hydrogen peroxide (H2O2), a reactive oxygen species. The ER-transmembrane protein that supports ER proteostasis and guards the cytosol for antioxidant defense remains unidentified. Here, we combine AlphaFold2 and functional screens in C. elegans to discover a previously uncharacterized and evolutionarily conserved protein ERGU-1 that fulfills these roles. Deleting ERGU-1 upregulates H2O2 and NRF2/SKN-1-dependent gene expression. ERGU-1 deficiency also impairs organismal reproduction and behavioral responses to H2O2. Both C. elegans ERGU-1 and human homolog TMEM161B localize to ER membranes, forming reticular networks. Human and Drosophila homologs of ERGU-1 rescue C. elegans mutant phenotypes, demonstrating ancient and conserved functions. In addition, purified ERGU-1 and TMEM161B exhibit redox-modulated oligomeric states. Together, our results reveal an ER-membrane-specific machinery, suggesting a conserved mechanism for maintaining ER redox homeostasis and proteostasis in animal cells.

Animals↗
PubMed2026

Bi-allelic loss-of-function variants in JKAMP cause a neurodevelopmental syndrome associated with dysregulation of GPR37 trafficking.

The endoplasmic reticulum (ER) serves as a key hub for protein homeostasis, maintaining a strict quality-control system that ensures only properly folded proteins reach their destinations, while misfolded proteins are degraded via ER-associated degradation (ERAD) or selective ER-phagy. JKAMP, which encodes an ER-resident transmembrane protein involved in ERAD, has not previously been associated with human disease. Here, we report bi-allelic loss-of-function variants in JKAMP in 14 affected individuals from 10 unrelated families presenting with a neurodevelopmental syndrome characterized by intellectual disability, developmental delay, seizures, hypotonia, microcephaly, and dysmorphic features. An in vivo zebrafish model lacking jkamp recapitulated key aspects of the human disorder, including developmental abnormalities and impaired myelin production, further corroborating its pathogenic role. Mechanistic studies identified GPR37, a brain-enriched orphan G protein-coupled receptor (GPCR) and known JKAMP interactor, as a critical downstream effector. GPR37 plays essential roles in dopaminergic signaling, inflammatory pain regulation, neuroprotection, and myelination. Loss of JKAMP resulted in defective folding and degradation of GPR37, leading to its accumulation within the ER and impaired trafficking to the plasma membrane, likely due to impaired ER quality control. These findings establish JKAMP as a previously unrecognized contributor to human neurodevelopment and uncover a pathogenic mechanism linking ER protein quality control to GPCR regulation and neurological disease.

Humans↗
PubMed2025

Analysis of stress-induced small proteins in Escherichia coli reveals that YoaI mediates cross-talk between distinct signaling systems.

Bacterial small proteins (≤ 50 amino acids) are an emerging class of regulators that modulate the activity of signaling networks that enable bacterial adaptation to stress. The Escherichia coli genome encodes at least 150 small proteins, most of which are functionally uncharacterized. We identified and characterized 17 small proteins induced in E. coli during magnesium (Mg2+) starvation using ribosome profiling, RNA sequencing, and transcriptional reporter assays. Several of these were transcriptionally activated by the PhoQ-PhoP two-component signaling system, which is crucial for Mg2+ homeostasis. Deletion or overexpression of some of these small proteins led to growth defects and changes in cell size under low-Mg2+ conditions, indicating physiological roles in stress adaptation. The small transmembrane protein YoaI, which was transcriptionally induced by the phosphate-responsive PhoR-PhoB signaling pathway, increased in abundance under Mg2+ limitation independently of yoaI transcription or PhoQ-PhoP signaling. YoaI activated a third signaling system, EnvZ-OmpR, which mediates responses to osmotic stress. Overall, this study establishes an initial framework for understanding how small proteins contribute to bacterial stress adaptation by facilitating cross-talk between different signaling systems. Our results suggest these proteins play broader roles in coordinating stress responses, reflecting the interconnected nature of cellular stress networks rather than strictly compartmentalized pathways responding to specific stressors.

Journal Article↗
PubMed2025

HIV-1 inhibits IFITM3 expression to promote the infection of megakaryocytes.

Despite an undetectable plasma viral load as a result of antiretroviral therapy, HIV-1-infected individuals with poor immune reconstitution harbor infectious HIV-1 within their platelets. Megakaryocytes, as platelet precursors, are the likely cellular origin of these HIV-1-containing platelets. To investigate the mechanisms that allow megakaryocytes to support HIV-1 infection, we established in vitro models of viral infection using hematopoietic stem cell-derived megakaryocytes and the megakaryocytic MEG-01 cell line. We observed HIV-1 DNA provirus integration into the megakaryocyte cell genome, self-limiting virus production, and HIV-1 protein and RNA compartmentalization, which are hallmarks of HIV-1 infection in myeloid cells. In addition, following HIV-1 infection of megakaryocyte precursors, the expression of interferon-induced transmembrane protein 3 (IFITM3), an antiviral factor constitutively expressed in megakaryocytes, was inhibited in terminally differentiated HIV-1-infected megakaryocytes. IFITM3 knockdown in MEG-01 cells prior to infection led to enhanced HIV-1 infection, indicating that IFITM3 acts as an HIV-1 restriction factor in megakaryocytes. Together, these findings indicate that megakaryocyte precursors are susceptible to HIV-1 infection, leading to terminally differentiated megakaryocytes harboring virus in a process regulated by IFITM3. Megakaryocytes may thus constitute a neglected HIV-1 reservoir that warrants further study in order to develop improved antiretroviral therapies and to facilitate HIV-1 eradication.

Humans↗
PubMed2026

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals↗
PubMed2026

Mapping cell-type- and age-dependent neuronal vulnerability through genome-wide in vivo CRISPRi screens in the mouse brain.

Current brain atlases are largely descriptive, cataloging correlative molecular snapshots such as gene expression signatures yet offering limited functional insight. Here, we develop a scalable, cell-type-resolved in vivo CRISPR interference (CRISPRi) platform enabling systematic gene function profiling in the mouse brain. Through genome-wide screens across four neuronal populations at three time points spanning youth to aging, we identify neuronal essential genes missed in vitro and define a consensus set of 269 neuronal core essential genes. The data reveal cell-type-specific genetic vulnerabilities, including divergent dependencies validated for exosome component 9 (Exosc9) and osteopetrosis-associated transmembrane protein 1 (Ostm1) between excitatory and inhibitory neurons. We uncover aging-specific dependencies enriched in mitochondrial and translational pathways, aligning with transcriptional changes in the aging human brain. Finally, we establish the CRISPRinvivo data portal as a community resource for in vivo screening. Altogether, this work provides a broadly applicable platform for in vivo functional genomics and a framework for building comprehensive gene-function brain atlases.

brain aging↗
PubMed2026

Hippocampal teneurin-4 knockdown promotes depression-like behavioral phenotypes by disrupting oligodendrocyte differentiation in mice.

Depression is one of the most prevalent mental disorders worldwide. The limited clinical efficacy of current antidepressants highlights identifying new therapeutic targets. Emerging evidence suggests that dysfunction of oligodendrocyte lineage cells contributes to the pathophysiology of depression. Teneurin-4 (Tenm4), a transmembrane protein that promotes oligodendrocyte differentiation and myelination, has been implicated in psychiatric disorders in genome-wide association studies; however, its causal role remains unclear. To determine whether Tenm4 contributes to depressive-like behavioral phenotypes, we examined Tenm4 protein expression in mice exposed to repeated forced swimming stress and generated hippocampal Tenm4 knockdown (Tenm4KD) mice. Chronic stress reduced Tenm4 expression levels in the hippocampus. Mice with hippocampus-specific Tenm4KD exhibited depressive-like behaviors, accompanied by reduced hippocampal myelin basic protein. Importantly, administration of clemastine, a myelin formation promoter, inhibited the reduction of myelin and attenuated depression-like behavioral phenotypes. Immunohistochemical analysis showed that Tenm4KD significantly decreased the number of mature oligodendrocyte cells and increased in the number of oligodendrocyte precursor cells, without changes in the total number of oligodendrocyte lineage cells. This study provides the first evidence that hippocampal Tenm4 deficiency induces depression-like behavior phenotypes through impaired oligodendrocyte differentiation and promoting demyelination. Our results identify Tenm4 as a molecular regulator of stress-induced behavioral phenotypes and suggest that it might represent a potential therapeutic target for mood disorders associated with demyelination.

Animals↗
PubMed2026

Genome-scale overexpression screening identifies product tolerance and efflux transport as key determinants of high-level L-tryptophan production in Escherichia coli.

L-tryptophan is a high-value aromatic amino acid widely used in the food, feed, and pharmaceutical industries. However, large-scale microbial production is constrained by insufficient precursor supply and limited strain tolerance to high product concentrations. In this study, modular metabolic engineering was first employed to enhance the availability of key precursors, including shikimate, serine, and glutamine, yielding strain TRPJ-13 with a 34.6% increase in L-tryptophan titer. To enhance strain tolerance, an indigo-based high-throughput reporter system was constructed and coupled with genome-scale overexpression library screening, leading to the identification of soxS as a tolerance-conferring target. Mechanistic analysis demonstrated that soxS upregulated lpxC to enhance lipopolysaccharide biosynthesis, thereby reinforcing membrane integrity and improving L-tryptophan tolerance. Combinatorial engineering of soxS and lpxC generated strain TRPJ-23, which increased L-tryptophan tolerance by 74.8% and L-tryptophan titer by 10.3%. Furthermore, YicL was identified as a novel transmembrane protein involved in L-tryptophan transport that effectively promoted L-tryptophan efflux, further increasing the titer by 9.0%. After fermentation optimization, strain TRPJ-28 produced 74.3 g/L L-tryptophan in a 5-L bioreactor, with a yield of 0.26 g/g and a productivity of 1.24 g/L/h. In a 1000-L pilot-scale bioreactor, TRPJ-28 reached a titer, yield, and productivity of 70.4 g/L, 0.25 g/g, and 1.17 g/L/h, respectively. This study provides new engineering insights for developing industrially promising L-tryptophan-producing strains.

Genome-scale overexpression screening↗
PubMed2003

Organic anion and cation transporters occur in pairs of similar and similarly expressed genes.

Organic anion and cation transporters (OATs, OCTs, OCTNs, and ORCTLs), transmembrane proteins essential to renal xenobiotic excretion, are encoded by a group of related genes. As yet there have been no studies of the transcriptional regulation of this important gene family. While such studies have traditionally been labor-intensive, comparative genomics approaches are now available that have proven reliable guides to critical regulatory elements. We report here the genomic sequencing of murine OAT1 (the cDNA of which was originally cloned by us as NKT) and OAT3 (Roct), and derivation of phylogenetic footprints (evolutionarily conserved non-coding sequences) by comparison to the human genome. We find binding sites within these footprints for several transcription factors implicated in kidney development, including PAX1, PBX, WT1, and HNF1. Additionally, we note that OATs and OCTs occur in the human and mouse genomes as tightly linked pairs (OAT1 and OAT3, UST3 and OAT5, OAT4 and URAT1/RST, OCT1 and 2, OCTN1 and 2, ORCTL3 and 4) that are also close phylogenetic relations, with Flipt1 and 2, and OAT2 the only unpaired family members. Finally, we find that pair-members have similar tissue distributions, suggesting that the pairing might exist to facilitate the co-regulation of the genes within each pair.

5' Flanking Region↗
PubMed2026

Protective TMEM106B-rs3173615 delays age at onset in GRN mutation carriers.

One of the major causative genes involved in Frontotemporal dementia (FTD) is Granulin (GRN), encoding for Progranulin (PGRN). GRN mutation carriers show a substantial heterogeneity with high variability in age at onset and pathological presentation, even within the same family or identical mutations, suggesting the presence of additional genetic factors. Single nucleotide polymorphisms in the Transmembrane protein 106B (TMEM106B) locus were identified as a genetic risk-associated factor for FTD. The top variant identified was the non-coding rs1990622, with the major allele (T) associated with an increased risk to develop FTD, while subjects with the minor allele (C) were less likely to develop disease, suggesting a protective effect. In this study, we investigate in a large Italian cohort of GRN mutation carriers, how the coding variant TMEM106B-rs3173615, in linkage disequilibrium with rs1990622, modulates age at onset, survival, and PGRN levels, including, up to date, the highest sample size of homozygous protective allele carriers. Genetic screening for TMEM106B-rs3173615 was performed on a total of 187 GRN mutation carriers, comprising 131 FTD patients and 56 pre-symptomatic subjects. Individuals with the protective genotype (GG) had a risk of FTD onset reduced by 80%, with a median age at onset of 77 years compared to a median age at onset of 63 years for individuals without the protective genotype. TMEM106B-rs3173615 acts as a genetic modifier of age at onset in the presence of GRN mutations and could be considered in clinical practice to optimize risk stratification for FTD.

Humans↗
PubMed2024

The Dectin-1 and Dectin-2 clusters: C-type lectin receptors with fundamental roles in immunity.

The ability of myeloid cells to recognize and differentiate endogenous or exogenous ligands rely on the presence of different transmembrane protein receptors. C-type lectin receptors (CLRs), defined by the presence of a conserved structural motif called C-type lectin-like domain (CTLD), are a crucial family of receptors involved in this process, being able to recognize a diverse range of ligands from glycans to proteins or lipids and capable of initiating an immune response. The Dectin-1 and Dectin-2 clusters involve two groups of CLRs, with genes genomically linked within the natural killer cluster of genes in both humans and mice, and all characterized by the presence of a single extracellular CTLD. Fundamental immune cell functions such as antimicrobial effector mechanisms as well as internalization and presentation of antigens are induced and/or regulated through activatory, or inhibitory signalling pathways triggered by these receptors after ligand binding. In this review, we will discuss the most recent concepts regarding expression, ligands, signaling pathways and functions of each member of the Dectin clusters of CLRs, highlighting the importance and diversity of their functions.

Lectins, C-Type↗