Biology subjects

Zhang, K.

Publications and source records attributed to Zhang, K..

At least 109 records · Page 6Linked to original sources

bioRxiv2025

Chryseobacterium indologenes mediates resistance to osimertinib by activating the IGF1R pathway in EGFR-mutant lung adenocarcinoma

IntroductionLung cancers harboring sensitizing epidermal growth factor receptor (EGFR) mutations typically exhibit an initial response to osimertinib; however, the development of resistance is inevitable, and there are currently no approved targeted therapies available once resistance emerges. Accumulating evidence indicates that intra-tumoral bacteria can influence tumor biology and contribute to therapy resistance in several cancer types, including pancreatic and colorectal cancer. Despite these findings, whether intra-tumoral bacteria play a role in modulating response and resistance to osimertinib in EGFR-mutant lung adenocarcinoma remains largely unexplored. This study aims to investigate the contribution of intra-tumoral bacteria to osimertinib resistance, thereby providing new insights into resistance mechanisms and identifying potential therapeutic strategies. MethodsBacteria previously identified in lung cancer tissue samples were cultured in liquid growth medium, and their preconditioned medium (PCM) was collected. PC9 cells were treated with PCM in the presence or absence of osimertinib to screen for bacteria capable of mediating resistance. Cell viability was assessed using Cell Counting Kit-8 assays. To investigate potential mechanisms, Western blotting and receptor tyrosine kinase (RTK) phosphorylation arrays were performed. Control groups included cells treated with osimertinib alone, PCM alone, or vehicle. Statistical analyses were conducted using Students t-test as appropriate, with p < 0.05 considered statistically significant. Data represent mean {+/-} SD from at least three independent experiments. ResultsThe addition of PCM from Chryseobacterium indologenes restored cell viability in EGFR-mutant lung adenocarcinoma cells treated with osimertinib. PCM exposure markedly increased insulin-like growth factor-1 receptor (IGF1R) phosphorylation levels. PCM did not enhance cell viability when IGF1R was silenced or inhibited with linsitinib, demonstrating the pathways essential role. Proteinase K treatment abolished the ability of PCM to protect cells from osimertinib, and removal of proteins potentially interacting with IGF1R further diminished its efficacy. Finally, PCM also conferred resistance to osimertinib in patient-derived EGFR-mutant lung adenocarcinoma cell lines. ConclusionOur study demonstrates that the intra-tumoral bacteria C. indologenes may significantly influence sensitivity to osimertinib or impart resistance in EGFR-mutant lung adenocarcinoma by activating the IGF1R signaling pathway.

cancer biology↗

bioRxiv2025

Lineage Tracing Reveals a Shared Cellular Origin for Supraclavicular Brown and Inguinal Beige Adipocytes

The metabolic importance of brown adipose tissue (BAT) has been recognized, but the origins of BAT, particularly supraclavicular BAT (scBAT), are less clear. Here, we traced the origin of scBAT to Mef2c-anterior heart field (AHF)-marked cells. Mef2c-AHF-marked cells isolated from scBAT can spontaneously differentiate into brown adipocytes, express mesenchymal stem cell markers, and can be isolated from the stromal-vascular fraction (SVF) of wild-type scBAT as [CD31-CD45-SCA-1+CD29+CD34-CD24-] (CD34-) cells. Mef2c-AHF-marked cells substantially overlap with Prrx1-marked cells in scBAT, which also contribute to beige adipocytes in inguinal white adipose tissue (iWAT) during development. Similarly, CD34- cells isolated from the SVF of iWAT can spontaneously differentiate into beige adipocytes in vitro. Using intersectional tracing, we revealed that common progenitors of Mef2c-AHF- and Prrx1-marked cells in scBAT emerge from the developing heart. Thus, these studies reveal a common origin for scBAT and cardiac tissue and a close lineage relationship between scBAT and beige adipocytes of the iWAT.

developmental biology↗

bioRxiv2025

A New Aneurysm Rupture-Prone Marfan Mouse Model with FBN1Q2467X Nonsense Mutation Reveals Adventitial Inflammation

Marfan syndrome (MFS) is a genetic disorder caused by mutations in fibrillin-1(FBN1), which encodes FBN1, a key structural component of the extracellular matrix. Mutations in FBN1 influence the severity of aortic disease and therapeutic responses, with aortic aneurysm being the leading cause of mortality in patients with MFS. To investigate the mechanisms driving aneurysm progression, we generated a mouse model (Fbn1Q2469X/+) carrying the FBN1Q2467X nonsense mutation identified in MFS patients. This mutation results in FBN1 deficiency. Although Fbn1Q2469X/+ mice appear normal, showing only mild, nonprogressive dilation of the aortic root and ascending aorta with minor reductions in blood pressure, homozygous Fbn1Q2469X/Q2469X mice develop spontaneous thoracic aortic aneurysms (TAA) that progress to rupture between 10 and 25 days of age, with 100% penetrance. Histopathology shows progressive vessel wall degeneration characterized by disorganized vascular smooth muscle cells, collagen loss, and elastic fiber fragmentation from early to late stages. RNA-seq analysis identifies inflammation as the dominant process in late-stage aneurysms. Immunofluorescence assay reveals inflammatory cells prominently localized to the adventitia near rupture sites, linking adventitial inflammation to aneurysm progression. This genetically modified Fbn1Q2469X/Q2469X mouse model consistently develops progressive aortic aneurysms and provides a reliable, cost-effective platform to investigate the molecular mechanisms of aneurysm progression and to evaluate therapeutic strategies in aneurysm diseases, including Marfan syndrome and related disorders.

genetics↗

bioRxiv2025

Shugoshin holds the potential to inhibit APC/C and thereby prevents separase activation

Accurate chromosome segregation during mitosis and meiosis depends on shugoshin protein which localizes at the centromere of chromosomes. Sgo1, a meiosis-specific shugoshin in fission yeast, collaborates with the PP2A phosphatase enzyme to remove phosphate groups from Rec8 cohesin, thereby preventing its cleavage by separase during meiosis. Here we show that ectopic expression of Sgo1 causes chromosome segregation errors during mitosis, especially in cut1-206 separase mutant cells, but that the D-box mutant Sgo1 has no effect in cut1-206 cells. Our molecular genetic analyses suggest that the D-box of Sgo1 directly binds Slp1/CDC20 and inhibits APC/C-dependent separase activation, thereby preventing cleavage of Rad21 cohesin. In contrast, during meiosis, the Sgo1 D-box mutant makes the cut1-206 mutant more difficult to cleave Rec8 cohesin. This is because the D-box mutation increases the amount of Sgo1 protein during meiosis, thereby enhancing its canonical protective ability against Rec8 cohesin. Thus, our studies using a separase mutant have revealed that Sgo1 has multiple faces to protect coheisn.

cell biology↗

bioRxiv2025

Protection and deprotection of the Rec8 cohesin complex during meiosis

In the first meiotic division, the cohesin Rec8 is cleaved by separase along the chromosome arms but is protected at the centromere by shugoshin (Sgo1), maintaining centromeric cohesion throughout meiosis I. Another meiotic regulator, meikin (Moa1), supports the protective function of Sgo1 primarily by phosphorylating S450 of Rec8. Both Sgo1 and Moa1 are meiosis I-specific proteins. Unlike fission yeast Sgo1, mammalian shugoshin (SGO2) persists at centromeres throughout meiosis I and II, but REC8 cohesin is protected only during meiosis I. Here, we show that fission yeast Moa1 and Sgo1 appear at kinetochores/centromeres from prophase I to metaphase I and are degraded during anaphase I by the APC/C-Slp1 pathway. We expressed non-degradable versions of Moa1 and Sgo1 in meiosis II and investigated how these proteins protect the cohesin Rec8 during meiosis II. Our analyses suggest that the localization of Sgo1 and the phosphorylation of Rec8 at S449 and S450 are necessary and sufficient events for protecting Rec8 cohesin during meiosis II. The absence of either event leads to deprotection at meiosis II.

cell biology↗

bioRxiv2025

Embryonic Atrial Injury Programs an Anti-Fibrotic Atrial Fibrillation Substrate

Atrial myopathy is associated with atrial fibrillation in adults, yet the role of embryonic atrial injury in predisposing individuals to atrial fibrillation remains unclear. Using an inducible, cardiomyocyte-specific diphtheria toxin A-mediated injury mouse model, we found that injured embryonic atria exhibited upregulation of apoptosis and TNF signaling pathways, alongside downregulation of calcium handling and atrial fibrillation-associated genes. Single-cell RNA sequencing revealed two distinct cardiomyocyte populations with differential injury responses. Importantly, although myofibroblasts increased in the fibroblast population, these cells displayed an extracellular matrix gene expression profile distinct from the pro-fibrotic phenotype typically observed in fibrillating adult atria and showed no evidence of fibrosis. Concurrently, monocytes/macrophages were activated and showed upregulated expression of the anti-fibrotic factor GPNMB. These findings suggest that adaptive tissue remodeling is counterintuitively prevented from progressing to fibrosis, potentially through GPNMB-mediated mechanisms. This study elucidates molecular pathways linking developmental atrial injury to myopathy and proposes novel strategies to attenuate atrial fibrillation progression.

pathology↗

bioRxiv2025

Improved cryo-EM reconstruction of sub-50 kDa complexes using 2D template matching

Visualizing the structures of small proteins and complexes has been a longstanding challenge in single-particle cryo-EM. Some of these targets have been successfully resolved by binding to antibody fragments (Fabs) or fusing with external scaffolds to increase their size. Recent advances in conventional single-particle techniques have enabled the determination of an increasing number of structures smaller than 100 kDa, achieving resolutions relevant to drug research. Compared to X-ray crystallography, cryo-EM preserves the near-native states of biomolecules, can resolve structural heterogeneity, and has the potential to apply to a wide range of targets. In this work, we demonstrate that the alignment and reconstruction of small macromolecular complexes can be improved using high-resolution structures as priors combined with 2D template matching. Using this method, we reconstructed a previously intractable [~] 43 kDa protein kinase and improved the density of its ligand-binding site. Our theoretical analysis predicts that this method can further extend single-particle cryo-EM to important drug-binding complexes well below 50 kDa. Cryo-EM | 3D reconstruction | signal detection | template matching 61

biophysics↗

bioRxiv2025

Loss of presenilin 2 function age-dependently increases susceptibility to kainate-induced acute seizures and blunts hippocampal kainate-type glutamate receptor expression

Presenilin 2 (PSEN2) variants increase risk of Alzheimers disease (AD) and unprovoked seizures. Yet, age-related PSEN2 contributions to seizure susceptibility are understudied. Critically, PSEN proteolytic capacity may regulate hippocampal kainate-type glutamate receptor (KARs) availability. Kainic acid (KA) is a KAR agonist that evokes severe seizures in mice. We hypothesized that PSEN2 knockout (KO) mice would show reduced latency to KA-induced seizures, increased seizure burden, worsened 7-day survival, and altered hippocampal KAR expression compared to wild-type (WT) controls. Using repeated low-dose systemic KA administration to 3-4- and 12-15-month-old PSEN2 KO versus WT mice, we quantified acute seizure latency and neuropathology. GluK2 and GluK5 KAR subunit expression was colocalized in astrocytes 7 days after seizures or sham to assess the impact of PSEN2 loss and seizures on hippocampal KARs. Young PSEN2 KO mice were more seizure-prone than WTs, while genotype did not change latency to first seizure. Aged females seized faster than young females and experienced greater mortality, unlike males. There was no difference in KAR subunit expression between young mouse genotypes and regardless of seizure history. In both genotypes, hippocampal CA3 astrocytes expressed GluK5 after seizures, however, astrocytic GluK2 upregulation only occurred in WTs. GluK5 expression was significantly reduced in aged seizure-naive PSEN2 KO versus WT mice, while total GluK2 expression did not differ. Seizure-induced astrocytic GluK5 expression only occurred in WT mice in CA3, while astrocytic GluK2 expression occurred in both. Thus, PSEN2 loss may impair age-related hippocampal KAR expression, implicating KARs as understudied contributors to AD-related seizures. Highlights.- Alzheimers disease (AD) and epilepsy share many pathophysiological links, but the contributions of distinct AD-risk factors are understudied. - Loss of normal presenilin 2 function is associated with AD; its role in late-life seizures and neuropathology have been minimally evaluated. - Loss of presenilin 2 increases susceptibility to kainic-acid induced acute seizures in young adult mice, mirroring late life risk. - Increased susceptibility to kainic acid induced acute seizures due to loss of PSEN2 is lost in late life, suggesting earlier senescence. - Loss of presenilin 2 function in aged mice is associated with reduced GluK5 expression and greater astrogliosis under basal conditions.

neuroscience↗

bioRxiv2025

Clinical and molecular features of primary gliosarcoma with digital spatial whole-transcriptome analysis of glial and mesenchymal components

Gliosarcoma is a rare subtype of IDH-wildtype glioblastoma defined by mixed malignant glial and high-grade sarcomatous histological elements. Gliosarcoma is clinically managed similarly to glioblastoma and has a poor clinical outcome. The sarcoma-like regions of gliosarcoma are thought to represent extreme mesenchymal metaplasia of neoplastic glial cells. Factors contributing to this phenomenon are not completely understood. Here we report a single-institution series of 37 gliosarcomas including next-generation sequencing data on 25 cases and digital spatial whole-transcriptome analysis on 4 cases to characterize differential gene expression between glial and mesenchymal components. Gliosarcoma demographic and genetic features were compared to a cohort of 75 primary adult hemispheric IDH-wildtype non-sarcomatous glioblastomas. Patient age, tumor location, sex, and overall survival in gliosarcoma were similar to glioblastoma. Gliosarcomas showed a significantly lower rate of EGFR amplification and a higher rate of NF1 mutation compared to glioblastomas in next-generation sequencing analysis. Digital spatial whole-transcriptome analysis showed a distinct transcriptomic profile in sarcomatous regions with over-expression of genes involved in extracellular matrix development and remodeling. Selected differentially expressed transcripts were examined further by immunohistochemistry. The glial elements of gliosarcomas showed higher immunoreactivity for Chitinase-3-like protein 1 (CHI3L1) than glioblastomas, but low to absent expression within the sarcomatous elements. Lymphoid Enhancer-Binding Factor 1 (LEF1) immunoreactivity was identified within sarcomatous regions of gliosarcoma without detectable nuclear {beta}-catenin, suggesting a role for {beta}-catenin independent wingless (WNT) effector signaling in sarcomatous transformation. This study adds to the growing literature demonstrating differences in the genetic underpinning of gliosarcoma and glioblastoma, establishes feasibility of spatial transcriptomic approaches in gliosarcoma, and validates digital spatial profiling-based results as a discovery platform to identify pathways and immunohistochemical markers for further study.

pathology↗

bioRxiv2025

Hypoimmunogenic human motor neurons induced from iPSCs in vivo substantially ameliorate ALS disease in large animal models

Stem cell-based therapy holds great potential for substituting degenerated motor neurons (MNs) in amyotrophic lateral sclerosis (ALS). Missing protocols for advanced differentiation of transplanted cells into MNs, immune rejection, and the lack of suitable ALS models for preclinical trials have slowed the development of effective therapies. Here, we employed multiplex genetic-editing to generate a novel human pluripotent stem cell line containing doxycycline (Dox)-inducible MNs-specific transcription factors and comprehensively modified immunomodulatory genes. We transplanted these cells into the spinal cord of ALS large animal models (SOD1G93A pigs and TIA1P362L rabbits), which faithfully recapitulate pathologies and symptoms observed in ALS patients. The transplanted cells could efficiently differentiate into functional MNs upon Dox treatment in vivo, distribute throughout the spinal cord and motor cortex via extensive migration, survive long-term without the need for immunosuppression. Notably, these MNs integrated into host neural circuits, as evidenced by their long projection of peripheral axons to target muscle and reformation of neuromuscular junctions. As result, pathologies and motor deficits were substantially ameliorated in both animal models. One Sentence SummaryHypoimmunogenic human motor neurons induced from iPSCs in vivo reform neuromuscular junctions and ameliorate ALS disease in pig and rabbit models.

neuroscience↗

bioRxiv2025

Real-Time Viability Assessment of Ex Vivo Mouse Kidneys for Transplant Applications Using Dynamic Optical Coherence Tomography

Kidney transplantation remains the preferred treatment for patients with end-stage kidney disease. However, the ongoing shortage of donor organs continues to limit the availability of transplant treatments. Existing evaluation methods, such as the kidney donor profile index (KDPI) and pre-transplant donor biopsy (PTDB), have various limitations, including low discriminative power, invasiveness, and sampling errors, which reduce their effectiveness in organ quality assessment and contribute to the risk of unnecessary organ discard. In this study, we explored the dynamic optical coherence tomography (DOCT) as a real-time, non-invasive approach to monitor the viability of ex vivo mouse kidneys during static cold storage over 48 hours. The dynamic metrics logarithmic intensity variance (LIV), early OCT correlation decay speed (OCDSe), and late OCT correlation decay speed (OCDSl) were extracted from OCT signal fluctuations to quantify temporal and spatial tissue activity and deterioration. Our results demonstrate that DOCT provides complementary functional information to morphological assessment offered by conventional OCT imaging, showing potential to improve pre-transplant organ evaluation and clinic decision-making.

bioengineering↗

bioRxiv2025

EBNA1 SUMOylation by PIAS1 Suppresses EBV Lytic Replication and Enhances Episome Maintenance

Epstein-Barr virus nuclear antigen 1 (EBNA1) is essential for the replication and stable maintenance of the viral episome in infected cells. Here, we identify the SUMO E3 ligase PIAS1 as a key regulator of EBNA1 through site-specific SUMOylation. Our Chromatin-Immunoprecipitation Sequencing (ChIP-seq) analysis revealed that PIAS1 is enriched at the viral origin of plasmid replication (oriP), where it physically associates with EBNA1 and catalyzes its SUMOylation. Using mutational analysis, we identified three lysine residues on EBNA1 (K17, K75, and K241) as major SUMOylation sites. Disruption of these sites compromises EBNA1s ability to restrict EBV lytic replication. In addition, both PIAS1 depletion and the disruption of EBNA1 SUMOylation lead to reduced retention of EBNA1-OriP-based EBV mini-replicon, indicating the importance of EBNA1 SUMOylation in viral episome maintenance. Together, these results uncover a conserved post-translational mechanism by which PIAS1-mediated SUMOylation modulates EBNA1 function and EBV episome maintenance and suggests a broader role for SUMOylation in viral latency, lytic replication and persistence. IMPORTANCEEpstein-Barr virus (EBV) persists in infected cells by maintaining its episome through the viral protein EBNA1. We discovered that PIAS1 SUMOylates EBNA1 at specific sites, a process essential for EBNA1 to retain viral episome and suppress reactivation. When SUMOylation is disrupted, EBV-based replicon becomes less stable and EBV is more likely to reactivate. These findings reveal a new layer of host control of EBV latency and reactivation, and highlight PIAS1-mediated EBNA1 SUMOylation as a key mechanism regulating viral persistence.

microbiology↗

bioRxiv2025

Visual Regularities Underlie Hierarchical Object Representations in the Human Brain and Self-supervised DNN

NeuroAI develops the interplay of neuroscience and artificial intelligence, especially on visual processing. Human visual system organizes objects based on a representational hierarchy. However, it remains unclear whether this hierarchy arises from visual or semantic information. One hypothesis posits that the visual system is structured around statistical regularities of visual information. Here, we test this hypothesis using the THINGS datasets and pure-visual deep neural networks (DNN). We constructed a low-dimensional object space based on multiple abstract object properties, reflecting statistical patterns of visual regularities. By applying voxelwise encoding models, we identified clusters in the higher visual cortex based on their property tuning, and they were found to support specific object categories. These clusters serve as the middle level to reveal a property-cluster-object hierarchical organization. Subsequently, we investigated whether this hierarchical structure could be captured by a self-supervised DNN. Through activity similarity analysis, we mapped the brain clusters onto the DNN and independently found that the DNNs clusters exhibited distinct property tuning and influenced the classification accuracy of corresponding object categories, mirroring the effects observed in the human brain. Our results demonstrate similar hierarchical structures in the human brain and self-supervised DNN, suggesting that the visual regularities shape neural architecture of visual system. This study highlights the great potential of neural computational model in neuroscience study. Index Terms Visual Processing, Abstract Property, Hierarchical Representation, Self-supervised Visual DNN

neuroscience↗

bioRxiv2025

Multi-modal characterization of transcriptional programs that drive metastatic cascades to solid sites and ascites in ovarian cancer

Ovarian high-grade serous carcinoma (HGSC) is characterized by extensive intra-peritoneal dissemination and tumor heterogeneity. In the metastatic cascade, tumors utilize several transcriptional programs to translocate and survive in distant tissues. Here, we analyzed multi-modal, real-world data from 350 tumor samples across 160 patients with HGSC to identify transcriptional programs that drive intra-peritoneal metastasis and heterogeneity. We identified nine transcriptional programs, including those regulating epithelial-mesenchymal transition and immune modulation and cytoskeletal reorganization, which shape distinct metastatic trajectories to solid and ascitic environments and are associated to treatment response. Our results reveal pronounced intra-patient transcriptional heterogeneity, which in some cases surpassed inter-patient heterogeneity, highlighting the importance of multi-site sampling for accurate prognostication and combinatorial treatments in HGSC. Our extensive characterization offers novel insights into intra-peritoneal metastasis with significant prognostic implications, reveals histomorphological biomarkers for patient stratification and paves the way for innovative therapeutic strategies aimed at impairing cancer cell adaptability and limiting metastasis.

cancer biology↗

bioRxiv2025

Comparative Temporal Transcriptomic Analysis of SOD1 Mutations in iPSC-Motor Neurons

Mutations in the SOD1 gene are among the most significant genetic contributors to amyotrophic lateral sclerosis (ALS), with different variants linked to varying disease severity. To investigate the molecular mechanisms driving this variability, we conducted RNA sequencing on spinal motor neurons (MNs) differentiated from isogenic human induced pluripotent stem cell (iPSC) lines engineered via CRISPR/Cas9. These lines carried two representative SOD1 heterogenous mutations, D91A and G94A, and were analyzed at Days 10 and 20 of neuronal maturation stage to capture the temporal changes of gene expression. We aim to explore how these mutations affect MN function, identify distinct molecular pathways that may explain the variable severity of ALS, and investigate the role of translation and metabolic dysregulation in disease progression.

bioinformatics↗

bioRxiv2025

Bottlebrush Polymer Conjugates for Enhanced Antisense Oligonucleotide Therapy in Myotonic Dystrophy Type 1

Oligonucleotides are a promising genetic medicine for myotonic dystrophy type 1 (DM1), the most common adult-onset muscular dystrophy. However, poor muscle distribution of nucleic acid drugs after systemic administration has hindered drug development, and no curative treatment exists. Additionally, DM1 pathology requires drug localization to the nucleus, where pathogenic mutant RNA is trapped, posing challenges after endocytosis and endosomal escape. Here, we show that a locked nucleic acid oligonucleotide targeting mutant CUGexp RNA tracts, conjugated to a bottlebrush polymer, exhibited improved muscle distribution and potent correction of DM1-associated splicing at low nanomolar doses in a DM1 mouse model. Significant improvements in myotonia, body weight, and grip strength were observed. The conjugates were well tolerated after 12 weeks of weekly intravenous dosing. These results suggest that bottlebrush polymer bioconjugates may overcome key limitations of traditional antisense drugs for muscular dystrophies, with the potential as potent, durable, and cost-efficient DM1 therapies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/668589v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@e3961corg.highwire.dtl.DTLVardef@194225dorg.highwire.dtl.DTLVardef@5c470dorg.highwire.dtl.DTLVardef@3cc46a_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2025

Single-cell multiomic human brain atlas reveals regulatory drivers of cortical regionality

Distinct regional functionality of the human cortex is orchestrated by diverse cellular and molecular processes, yet the underlying regulatory mechanisms remain poorly understood. We performed multiomic single-cell and spatial characterization of nine regions of the human cortex to define the gene regulatory networks and transcription factors that govern cell-type and region specificity. With the combined data of over three million cells, two striking patterns of cortical neuron specialization were uncovered: a rostral-caudal gradient of calcium regulatory machinery, and subunit switching of multiple signaling receptor families across the transmodal-sensory axis. Gene regulatory network analysis revealed putative transcriptional regulators of cortical neuron specialization with cell-type- and region-specific gene regulation patterns. While regionalization was observed in gene expression, chromatin accessibility, and spatial distributions, these modalities exhibited distinct cortical patterns. Our findings illuminate critical neuronal pathways that vary throughout the cortex and the gene regulatory networks that establish cortical regionalization in the human brain.

neuroscience↗

bioRxiv2025

Organelle membrane-associated proteins recruit cGAS via phase separation to facilitate its membrane localization

Double-stranded DNA is recognized as a danger signal by cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS), triggering innate immune responses in mammals. As a DNA sensor, cGAS is generally believed to distribute in the cytoplasm, whereas alternative subcellular localization of cGAS, including cytoplasmic membrane and nucleus, is important to regulate its activity. However, it remains obscure whether cGAS could localized to organelle membrane and the mechanism has yet to be uncovered. Our study reveals that cGAS could localize to the endoplasmic reticulum, Golgi apparatus, and endosomes upon DNA challenge. We identified that the post-translational modification enzymes ZDHHC18 and MARCH8, through their intrinsically disordered regions (IDRs), facilitate the binding of cGAS to the Golgi and endosome, respectively. These IDRs phase separated to recruit cGAS and double-stranded DNA (dsDNA) into biomolecular condensates, suppressing cGAS activity and downstream signaling pathways. These findings highlight the regulatory mechanisms of cGAS activity through the spatial organization, providing new insights into the modulation of innate immune responses.

cell biology↗