Biology subjects

Yang, G.

Publications and source records attributed to Yang, G..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Opposing regulatory logics converge on ABA receptors to govern the trade-off between growth and drought acclimation

Plants dynamically balance growth with stress responses through abscisic acid (ABA). How ABA signaling, but how ABA sensitivity is finely tuned is unclear. Here, we uncover a regulatory network of leucine-rich repeat receptor-like kinases (LRR-RLKs) that directly controls ABA receptors stability. We identify GASSHO1 (GSO1) as a core component that phosphorylates the PYL2 and PYL4 receptors, targeting them for degradation and thus serving as a brake on ABA signaling. Under drought stress, ABA accumulates and suppresses expression of GSO1-activating CIF peptides, releasing this brake to increase PYLs and sensitivity. This mechanism opposes our previously identified CEPR2 pathway, where drought-induced CEP peptides inhibit the kinase to stabilize PYLs. The integration of these two antagonistic modules within an LRR-RLK network enables precise, dynamic control of ABA perception. This work reveals a molecular framework explaining how plants calibrate the critical balance between growth and drought acclimation.

molecular biology↗

bioRxiv2026

STING safeguards epithelial genome integrity and protects from carcinogenesis via mitotic checkpoint control

STING is canonically known for mediating interferon responses to cytosolic DNA, yet its cell-intrinsic role in genome maintenance beyond the immune context is unknown. Here we show that epithelial STING functions as a type I interferon-independent genome-integrity checkpoint. STING loss impairs homologous recombination repair, attenuates ATM-associated damage signaling, elevates CDK1 activity, and causes chromosomal instability revealed by single-cell Strand-seq, culminating in spontaneous intestinal adenocarcinoma. These defects arise before tumor formation and confer selective vulnerability to CDK inhibition in tumor organoids and human colorectal cancer cells. Our findings identify STING as a cell-autonomous guardian of epithelial genome stability that restrains chromosomal instability-driven tumor evolution beyond its canonical immune function.

cancer biology↗

bioRxiv2026

IFN gamma-induced IRF1 synergizes with TLR7 signals to tune the IRF4-IRF8 axis and drive pathogenic effector B cell fate

Interferon regulatory factor 1 (IRF1), a transcription factor encoded within the 5q31 locus harboring systemic lupus erythematosus (SLE) associated variants, promotes inflammatory responses by T and myeloid cells. Although IFN{gamma}-activated B cells also express IRF1, its role in B cell biology and SLE is unclear. Here, we use a mouse SLE model, single-cell multiomics, and human B cells to show that IRF1 intrinsically regulates Irf4 gene chromatin accessibility and expression in B cells to control the balance between the antibody secreting cell (ASC) lineage commitment factor, IRF4, and the B cell identity factor, IRF8. We demonstrate that IRF1, through its integration of IFN{gamma} and TLR7 induced transcriptional programs, tips B cells toward a terminal effector inflammatory AC fate at the expense of preserving more stem-like, resting and regulatory B cells that do not elicit autoantibody-associated pathology in SLE. Thus, IRF1 serves as a central node controlling B cell-driven autoimmune disease.

immunology↗

bioRxiv2026

G3DCT: An Interpretable Spatial Grid-based Framework with Temporal Convolution-Transformer for EEG Artifact Identification

Electroencephalography (EEG) serves as a fundamental tool in modern neurology, cognitive neuroscience, and brain-computer interfaces, but its practical application is often compromised by artifacts. Physiological artifacts are particularly intractable due to overlapping spectral features with neural signals, hindering reliable EEG interpretation. In this work, we propose Grid-based 3D Convolution-Transformer (G3DCT), an interpretable deep learning framework for EEG artifact identification. The framework embeds multi-channel EEG signals into fixed grids to leverage electrode spatial topology, employs parallel multi-branch temporal convolutions and Transformers to handle complex artifacts, and incorporates an attention module to visualize scalp activation patterns, which enhances physiological interpretability. Our evaluation on three datasets demonstrates that G3DCT outperforms existing state-of-the-art models. For challenging combined artifacts, it secures a gain of 2.8% in F1-score over the second-best model. These results demonstrate that G3DCT provides an efficient and robust solution for EEG artifact identification, which has the potential to enhance the reliability of EEG-based applications in practice.

neuroscience↗

bioRxiv2026

Near completely reversing the γ- to β-globin switch by enhancer release, retargeting and reinforcing

The {gamma}- to {beta}-globin switch is intricately regulated during human ontogeny, and this process is manipulated for therapeutic approaches to treat {beta}-hemoglobinopathies by activating {gamma}-globin expression. Several genetic strategies to reactivate HbF have partially reversed the {gamma}- to {beta}-globin switch and ameliorated the clinical symptoms of {beta}-hemoglobinopathies. However, whether the {gamma}- to {beta}-globin switch can be completely reversed remains unknown. Completely reversing the {gamma}- to {beta}-globin switch requires a thorough redirection of the locus control region (LCR) from interacting with the {beta}-globin gene (HBB) to interacting with the {gamma}-globin gene (HBG). Here, we found that disrupting the KLF1-mediated HBB-LCR interaction by mutating the CACCC motif in HBB leads to the release of the LCR and its retargeting to other {beta}-like globin genes. Moreover, simultaneously disrupting the KLF1-mediated HBB-LCR interaction and the epigenetic repression of HBG by combined editing of the CACCC motif in HBB and the TGACCA motif in HBG reinforces the HBG-LCR interaction, resulting in almost exclusive {gamma}-globin expression while nearly absent {beta}-globin expression, achieving near complete reversal of the {gamma}- to {beta}-globin switch. This finding demonstrates the comprehensive regulation of the {gamma}- to {beta}-globin switch by gene competition and gene silencing mechanisms. This finding also suggests that silenced genes can be fully activated through the redirection of enhancer-promoter contacts and that the specificity of enhancer-promoter contact within chromosomal domains is achieved through the transcription factor clusters binding to enhancers and promoters. Combined editing of the CACCC&TGACCA motifs also offer a more optimal therapeutic strategy for {beta}-hemoglobinopathies.

molecular biology↗

bioRxiv2026

Human T Cells From Resistant Hypertension Patients Promote Hypertension via TNF in humanized mice

ObjectivePreclinical studies suggest a pivotal role of adaptive immunity, particularly T cells, in hypertension. However, due to the multifactorial pathogenesis, there is still no definitive evidence for a causal role of T cells in the development of hypertension in humans. We sought to determine whether T cells from patients with treatment-resistant hypertension (TRH) directly modulate blood pressure and vascular function in vivo. MethodsPeripheral blood mononuclear cells (PBMCs) from TRH patients and healthy controls (HC) were adoptively transferred into immunodeficient NSG-(KbDb)^null mice. Hypertension was induced by angiotensin II infusion for 14 days and monitored continuously by radiotelemetry. ResultFollowing T cell engraftment, blood pressure was assessed at baseline and during AngII infusion in both groups of recipient mice. At baseline, systolic blood pressure did not differ between both groups. However, mice receiving TRH-PBMCs developed a significantly higher systolic blood pressure following AngII compared with HC-PBMC recipients. Endothelial dysfunction in isolated perfused kidneys was more pronounced in AngII-challenged TRH-PBMC recipients compared to HC-PBMC recipients. TRH-PBMC recipients displayed elevated effector memory CD4 T cells and Th17 frequencies in spleen and kidney, along with markedly increased renal expression of human T cell-derived TNF. Overnight incubation of mouse aortic rings with human TNF induced endothelial dysfunction, indicating a causal role of T cell-derived TNF. As a proof of concept, TNF inhibition attenuated AngII-induced hypertension in TRH-PBMC-engrafted mice. ConclusionT cells from patients with treatment-resistant hypertension promote an exaggerated hypertensive response and endothelial dysfunction in PBMC-engrafted humanized mice, promoted by TNF-mediated mechanisms. These findings provide evidence that T cell-derived TNF may contribute to the pathogenesis of human hypertension.

immunology↗

bioRxiv2026

Iron Deficiency Drives Sarcopenia in the Elderly: HIF-1α-Mediated Fibro-Adipogenic Progenitor Differentiation Induces Fat Infiltration and Impairs Muscle Function

Abnormal iron metabolism is closely linked to sarcopenia; however, the specific iron metabolism features of fat-infiltrating sarcopenia remain poorly understood. Proteomic sequencing revealed that in skeletal muscle with severe fat infiltration, the expression of iron utilization-related proteins was significantly downregulated, whereas that of iron uptake and storage proteins was markedly upregulated, thereby presenting an abnormal iron deficiency (ID) phenotype. Nevertheless, the mechanism by which ID drives intramuscular fat infiltration has not been fully elucidated. Using clinical samples, aged murine ID models, and in vitro cell assays, this study is the first to demonstrate that ID stabilizes hypoxia-inducible factor-1 (HIF-1), promoting aberrant adipogenic differentiation of fibro-adipogenic progenitors (FAPs), disrupting the homeostatic balance between satellite cells (SCs) and FAPs, exacerbating skeletal muscle fat infiltration, and impairing muscle repair capacity. Notably, treatment with the HIF-1 inhibitor PX478 reversed these pathological alterations and improved muscle function. Collectively, our findings identify the ID-HIF-1-FAPs axis as a key driver of intramuscular fat infiltration, offering a novel therapeutic target for the clinical management of fat-infiltrating sarcopenia.

cell biology↗

bioRxiv2025

PARP1 Writes N3-Cytidine ADP-Ribosylation in DNA

Recent evidence indicates that mono - and poly-ADP ribosylation (MARylation and PARylation) are not limited to proteins but extend to DNA. Notably, in vitro base PARylation by PARP1 in single stranded DNA (ssDNA) was demonstrated at N1-deoxyadenosine (N1-dA). Here, we report that PARP1 catalyzes N3-specific ADP-ribosylation of deoxycytidine (N3-dC) in single-stranded DNA. Analogous to N1-dA PARylation, which is prone to spontaneous adenine-to-inosine deamination, N3-dC PARylation promotes cytosine deamination, yielding N3-PARylated-deoxyuridine. These deamination products yield diagnostic PARylation signatures in LC-MS/MS, namely N1-ribosyl-deoxyinosine (N1-r-dI) and N3-ribosyl-deoxyuridine (N3-r-dU). We synthesized both N1-r-dI and N3-r-dU as diagnostic standards and established absolute quantification of base ADP-ribosylations by LC-MS/MS. Quantitative analysis of PARylated dA and dC in ssDNA reveals pronounced sequence preferences of PARP1. Removal of these base modifications differs markedly, since ADP-ribose glycohydrolase TARG1 removes PAR from both dA and dC, whereas PARG acts exclusively on dA. Our results establish cytidine ADP-ribosylation as a novel DNA modification, with potential roles in DNA metabolism, epigenetic regulation, or genome stability.

biochemistry↗

bioRxiv2025

Dissecting Epstein-Barr Virus Dependence Across Diverse Infected Cell Models

Epstein-Barr virus (EBV) is maintained clonally in a wide array of tumors and cells of lymphoproliferative disorders, yet the degree to which these infected cells continuously depend on EBV remains unresolved. To directly assess EBV dependence, we used two complementary Cas9-based viral eviction strategies: 1) targeting EBNA1 to promote episome dilution during cell division, and 2) targeting repetitive viral genomic regions to rapidly degrade EBV episomes. Using these approaches, we evaluated EBV-loss sensitivity across newly-derived, phenotypically diverse EBV-positive Burkitt lymphoma lines. We also evaluated cell lines from patients with EBV-associated T/NK and epithelial malignancies. We included the Burkitt Lymphoma cell line, Akata-GFP, as our EBV-loss-tolerant control and a lymphoblastoid cell line as our EBV-loss-sensitive control. We observed EBV-loss sensitivity in all the EBV-positive Burkitt Lymphoma cell lines and the chronic active EBV disease cell line. In contrast, the EBV-positive gastric adenocarcinoma lines were markedly less sensitive to EBV loss. EBV latency type did not predict EBV dependence, indicating that viral gene expression programs alone do not dictate reliance on the virus. These findings demonstrate that EBV dependence is prevalent across multiple EBV-associated disease models and is especially pronounced in early-state or newly derived lymphoid malignancies. AUTHOR SUMMARYEpstein-Barr virus (EBV) infects most people worldwide and is linked to many malignancies. Although EBV is present in cancer cells, it is unclear whether these cells require the virus to survive. To answer this question, we used CRISPR/Cas9-based methods to remove EBV from infected cells. Using these tools, we studied many different EBV-positive cell lines, including new Burkitt lymphoma cell lines. We found that most EBV-positive lymphoid cells required EBV for growth. In contrast, EBV-positive gastric cells were more tolerant of viral loss. These results show that many EBV-associated malignancies, especially early or newly established diseases, rely on EBV to survive.

microbiology↗

bioRxiv2025

The urinary pathobiont Actinobaculum massiliense generates androgens via the dirAB pathway

While overlooked during the Human Microbiome Project, characterizing the urinary microbiota in health and disease is a new frontier in microbiome science. Recent studies have associated differential abundance of bacterial taxa including Propionimicrobium lymphophilum and Actinobaculum/Actinotignum spp. with prostate cancer. In this study, we collected urine from subjects prior to prostate biopsy and applied a novel Human Sterolbiome Discovery High-throughput (HSDH) assay to identify culturable urinary bacteria with the ability to generate androgens. Application of the HSDH assay to urine samples led to the isolation of eight P. lymphophilum strains positive for cortisol side-chain cleavage (steroid-17,20-desmolase), 17{beta}-HSDH activity, or both. In addition, we isolated three strains of Actinobaculum massiliense that encode DHEA isomerase reductase (dir) genes. The dirA gene encodes a novel 3{beta}/17{beta}-hydroxysteroid dehydrogenase/{Delta}4,5-isomerase and the dirB gene encodes a novel 17{beta}-hydroxysteroid dehydrogenase isoform. Structural prediction and molecular dynamics reveal probable catalytic mechanisms based on the shared catalytic triad but distinct binding pocket geometries of the DirA and DirB that describe their respective reactions. Phylogenetic analysis of DirA and DirB revealed homologs in urinary tract commensals as well as bacteria associated with steroid degradation found in aquatic and terrestrial environments. Taken together, the development of the HSDH assay and the identification of the dir pathway genes is a significant advance in microbial endocrinology, laying the methodological foundation and providing the molecular basis for understanding the role of urinary tract bacteria in host endocrine physiology.

microbiology↗

bioRxiv2025

A neuron type-specific microexon in Ank3/ankyrin-G modulates calcium activity and neuronal excitability

Recent studies have revealed many alternative exons differentially spliced across diverse neuron types in the mammalian brain, but their links to neuronal physiology remain unclear. Here we characterize a deeply conserved microexon E35a in Ank3 encoding ankyrin-G (AnkG), a multifaceted adaptor protein best known as a master organizer of the axon initial segment (AIS) and as a leading genetic risk factor for bipolar disorder. E35a is predominantly skipped in cortical glutamatergic neurons but included in cortical GABAergic neurons and cerebellar neurons, which is dictated by multiple neuronal splicing factors. In E35a-deletion mice we generated, interneurons show increased excitability and somatic Ca2+ activity, without disruption in AIS. Biochemical analyses suggest that E35a inclusion facilitates AnkG interaction with a protein complex involving inositol trisphosphate receptors (InsP3Rs) important for intracellular Ca2+ signaling. Alternative splicing therefore allows AnkG to modulate neuron type-specific excitability in addition to its ubiquitous pan-neuronal role in organizing the AIS.

neuroscience↗

bioRxiv2025

snoCLASH Reveals Extensive snoRNA-mRNA Interaction Networks

Small nucleolar RNAs (snoRNAs) are classically defined as guides for modification of ribosomal RNA (rRNA) and small nuclear RNA (snRNA), yet increasing evidence suggests that box C/D snoRNAs also interact with non-canonical transcripts. Systematic discovery of such interactions has been hindered by overwhelming rRNA abundance and technical limitations in RNA-RNA capture. Here, we present snoCLASH, an optimized snoRNA:RNA binding protein (RBP)-based crosslinking, ligation, and sequencing framework that integrates phenol-toluol extraction, polyA enrichment, nuclear fractionation, rRNA depletion, and dual-reference chimeric read analysis to enable transcriptome-scale identification of snoRNA-non-rRNA interactions. Applying this approach reveals thousands of snoRNA-associated mRNA regions spanning coding and regulatory elements and enriched for RBPs linked to epitranscriptomic regulation. Using this framework, we identify high-confidence snoRNA-mRNA interactions and functionally validate OGA mRNA as a snoCLASH-discovered target undergoes snoRNA-dependent 2-O-methylation with downstream effects on protein expression. Together, this work establishes snoCLASH as a platform for discovering and validating non-canonical snoRNA targets beyond rRNA. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=56 SRC="FIGDIR/small/693487v2_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@13d9a4corg.highwire.dtl.DTLVardef@15d12fdorg.highwire.dtl.DTLVardef@189ac06org.highwire.dtl.DTLVardef@17ceeea_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

Dual Transcriptional Drivers of Immune Suppression in SACC: NOTCH1 for Cellular and MYB for Humoral Immunity

As a classic immune-"cold" tumor, salivary adenoid cystic carcinoma (SACC) represents a significant clinical challenge. Through sequencing analyses, we identify profound systemic immune dysregulation in SACC, characterized by suppressed hematopoiesis, T-cell exhaustion, compensatory myelopoiesis, and an expanded immature B-cell compartment. While lung metastases exhibit a relatively immune-engaged microenvironment enriched in tissue-resident T cells, these sites remain dominated by immature B cells. Mechanistically, this hematopoietic dysfunction originates from direct disruption of tumor-derived signaling entering the circulation, supported by detection of the SACC-signature MYB-NFIB fusion gene in peripheral plasma and blood cells. At the molecular level, we discover that IL17RB/OLIG1/NOTCH1 signaling pathways engage in multicellular crosstalk via IL33 or TP53 to suppress T-cell activation in primary tumors. Moreover, at lung metastatic sites, the MYB/MYBL2-NOTCH1-CXCL13-CXCR5 axis is blocked through CD24 or IL17RB, thereby inhibiting B-cell maturation. Single-cell transcriptomic profiling further identifies cancer stem cells (CSCs) exhibiting dual characteristics of cell-cycle activity and immune progenitor features, a finding that clarifies the fundamental mechanism by which these cells evade immune surveillance. In conclusion, we propose that stem cell camouflage constitutes the core mechanism underlying bone marrow hematopoietic dysfunction and drives immune evasion in SACC. These findings highlight the IL17RB-NOTCH1 signaling axis as a promising therapeutic target, offering potential to overcome the long-standing challenges associated with NOTCH1-targeted therapies in this malignancy. SignificanceOur novel transcriptomic analysis revealed a key G2M/CLP dual-progenitor state in SACC immunocold tumors. Tracing its origin to hematopoietic differentiation, we uncovered a NOTCH1-mediated dual-hit mechanism: restricting antigen presentation to silence T cells while partnering with MYB to block B-cell maturation. This finding pinpoints a root cause of immune evasion and establishes this pathway as a central therapeutic target. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=107 SRC="FIGDIR/small/688163v2_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@18c22a2org.highwire.dtl.DTLVardef@135e381org.highwire.dtl.DTLVardef@eb4eadorg.highwire.dtl.DTLVardef@7a51c4_HPS_FORMAT_FIGEXP M_FIG C_FIG Dichotomous gene mapping and single-cell interactome reveal the microenvironmental specificity of NOTCH1/MYB regulation of T/B-cell differentiation and its distinct signaling flows.

immunology↗

bioRxiv2025

The Cortical Temporal Axis: MEG-Based Cross-Frequency Gradients with Biological Anchors

Neural oscillations have long been used to characterize the temporal dynamics of individual brain regions, yet a parsimonious, system-level representation that integrates multi-rhythmic activity has been lacking. Using source-localized resting-state magnetoencephalography (MEG) data, we computed regional power spectra and assessed spectral similarity, then applied diffusion map embedding to construct cross-frequency neurophysiological gradients that place whole-brain oscillations within a unified, low-dimensional coordinate system. We found the first three gradients accounted for over 40% of the variance, remained stable across individuals, and aligned with established functional, structural, and geometric cortical axes. Computational modeling showed that these gradients reflect local excitation-inhibition balance, while multimodal analyses revealed strong associations with neurotransmitter receptor distributions, cytoarchitecture, and cell-type-specific gene expression. Lifespan analyses further demonstrated systematic gradient reorganization, with distinct cognitive mappings onto functions such as language, memory, and multisensory integration. Clinically, Parkinsons disease patients displayed disrupted gradients, particularly in regions linked to language and social cognition. Finally, these gradient patterns exhibited high test-retest reliability. These findings establish MEG-derived neurophysiological gradients as robust, low-dimensional representations of cortical organization, offering a biologically grounded framework for studying brain aging and disease.

neuroscience↗

bioRxiv2025

Normative models of individualized functional brain networks reveal language network expansion in autism

Autism spectrum disorder is a highly heterogeneous neurodevelopmental disorder, hindering mechanistic insights and the identification of biomarkers for clinical diagnosis. Recently, precision functional mapping has been developed to identify abnormalities in brain network topologies associated with various psychiatric disorders, yet its application in autism remains limited. Here, we utilized precision functional mapping and a large, multisite neuroimaging dataset (N = 1,182) to construct individualized functional networks in individuals with autism. We developed normative models using network surface area from healthy controls (n = 628) to characterize typical brain network organization across age, allowing for the quantification of individual-specific deviations in individuals with autism (n = 554). We found widespread and heterogeneous deviations from the normative model, with the language network emerging as the most significantly altered region, thereby emerging as an epicenter of functional disruption in autism. Individuals with autism were clustered into three subtypes involving distinct functional network topologies, associated with behavioral profiles marked by impairments in perception, language processing, or socio-emotional functioning. We further linked these atypical brain features to cortical gene expression patterns, revealing enriched pathways related to neurodevelopment, language, and signaling processes. Together, these findings reveal autism-specific deviations in individualized functional brain networks, offering potential clinical relevance for understanding and stratifying autism.

neuroscience↗

bioRxiv2025

Mucosal delivery of influenza antigens using a replication deficient adenovirus supports broadly reactive antibody responses and heterologous viral immunity in the respiratory tract of animals

Systemically administered influenza vaccines provide strain-limited protection, while influenza infection of the respiratory epithelium supports development of lung resident memory B and T cells and more broadly reactive antibody responses. To test whether local antigen delivery is critical for establishing broad immunity, we directly compared respiratory tract and systemic delivery of influenza antigens to mice and hamsters using a replication-deficient adenovirus serotype 5 vector (Ad5[E1-,E2b-,E3-]). Both immunization routes elicited antibody responses in the lower respiratory tract and antigen-specific B and T cells in the draining lymph node. However, only intranasal immunization established lung-resident memory B and T cells, induced IgA responses in the upper respiratory tract directly at the site of viral entry and supported generation of IgA and IgG antibodies that bound antigenically drifted and distantly related influenza strains, including those of avian origin. Intranasal immunization accelerated viral clearance following heterologous virus challenge and was associated with limited pulmonary inflammation and fibrosis. Thus, intranasal immunization with the immunologically stealthy Ad5[E1-,E2b-,E3-] platform supports respiratory and systemic immunity to divergent influenza strains in the absence of overt lung immunopathology, suggesting that local antigen delivery may be key to development of more broadly protective "universal" flu vaccines.

immunology↗

bioRxiv2025

The evolution and mechanistic versatility of the bacterial NADH dehydrogenases type II

Type II NADH dehydrogenases (NDH-2s) are accessory enzymes of the bacterial electron transport chain (ETC). While they functionally overlap with Complex I, their main role is not proton translocation but maintaining the intracellular NADH/NAD+ balance. Although often non-essential, NDH-2 become crucial in species lacking complex I, serving as the primary electron entry point into the ETC. Their virtual absence in mammals makes these enzymes attractive targets for antimicrobial drug development and mitochondrial functional restoration. NDH-2s catalyze electron transfer from NADH to quinones, yet two distinct catalytic mechanisms have been described for members of the family: a classical ping-pong mechanism and an atypical ternary mechanism involving the formation of a charge transfer complex (CTC). The molecular basis of these mechanisms remains unclear. Also, their occurrence among NDH-2s from different bacterial lineages in unknown. Here we combined molecular phylogenetics, ancestral sequence reconstruction, expression and biochemical characterization of ancestral and modern enzymes and, molecular dynamics simulations to explore the mechanistic versatility of NDH-2s across Bacteria. Our results show the atypical ternary mechanism is restricted to the Firmicutes (Bacillota) lineage and it is defined by the presence of a single substitution located at the bottom of the active site. This work provides an evolutionary framework for understanding NDH-2 mechanistic versatility. Besides, it establishes a basis for drug discovery targeting pathogenic strains and opens avenues to develop innovative strategies to complement dysfunctional mitochondria.

biochemistry↗

bioRxiv2025

PRRT2 as an auxiliary regulator of Nav channel slow inactivation

During sustained activity, voltage-gated sodium (Nav) channels enter a slow-inactivated state to limit cellular hyperexcitability. Disruption of this regulatory process has been implicated in skeletal, cardiac and neurological disorders. While the kinetics of this process are well characterized, its endogenous modulators remain unclear. Here, we identify Proline-Rich Transmembrane Protein 2 (PRRT2) as a native regulator of Nav channel slow inactivation. We show that PRRT2 facilitates the entry of Nav channels into the slow-inactivated state and delays their recovery, a regulatory effect conserved from zebrafish to humans. PRRT2 forms molecular complexes with Nav channels both in vitro and in vivo. In the mouse cortex, PRRT2 deficiency impairs the slow inactivation of Nav channels in neuronal axons, leading to reduced cortical resilience in response to hyperexcitable challenges. Together, these findings establish PRRT2 as a physiological modulator of Nav channel slow inactivation and reveal a mechanism that supports cortical resilience to pathological perturbations.

neuroscience↗