Biology subjects

Yang, Z.

Publications and source records attributed to Yang, Z..

At least 181 records · Page 10Linked to original sources

bioRxiv2025

Two high-quality rose genomes underpin a novel Rosa pangenome to advance rose genomics, phylogenetics, and breeding

Rosa, belonging to the family Rosaceae, encompasses more than 150 species which are widely distributed in the northern hemisphere. Renowned for their beauty, roses are cultivated throughout the world for ornamental purposes and the production of essential oils and perfumes. Despite their cultural and commercial significance, the genomic resources of wild Rosa species have not been studied comprehensively, hampering the understanding of their genetic diversity, evolutionary history, and breeding potential. Here we report on high-quality de novo genomes for Rosa sericea and Rosa rugosa. By integrating these two de novo genomes with existing public genomic resources, we have built a Rosaceae panproteome and a Rosa pangenome (spanning wild, traditional garden, and modern rose lineages) using a De Bruijn graph (DBG)-based approach. A maximum likelihood (ML) phylogeny of 18 Rosa haplotypes based on 4,367 single-copy core homology groups (genes) provided robust evolutionary inference, confirming the basal position of R. sericea, and enabled a gene-based macrosynteny analysis across the pangenome. Our analyses revealed significant genomic diversity among species, extensive variation in core gene content, and lineage-specific transposable element (TE) expansion patterns that contribute to the variation in Rosa genome size and to species-specific adaptations. The pangenome also revealed biased diversification of homology groups potentially linked to phenotypic plasticity in Rosa. Specifically, our analysis of the rose scent-related gene family, NUDX1, uncovered its evolutionary trajectory in Rosa, in which TEs insertions provided putative novel regulatory elements that facilitated adaptive evolution in metabolic pathways. This pangenomic study deepens our understanding of the genetic diversity and evolution of traits within the Rosa genus. In addition, the findings lay the foundation for future efforts to understand the genetic mechanisms driving trait evolution, which can support rose breeding.

genomics↗

bioRxiv2025

All-Atom Modeling and Simulation of Biopolymer Interface: Dual Role of Antifouling Polymer Brushes

Antifouling polymers are highly valuable in a variety of applications, including antiviral coatings, targeted drug delivery, and marine coatings, where preventing unwanted protein adsorption is critical. Although extensive experimental studies have characterized polymer-protein interactions, computational studies remain limited due to the inherent difficulty of modeling and integrating these distinct components within a unified system. This study presents molecular modeling and simulation of polyelectrolyte and polyzwitterionic brushes--poly(dimethylaminoethyl methacrylate) (PDMAEMA), poly(2-(N-oxide-N,N-dimethylamino)ethyl methacrylate) (PNOMA), and poly(2-(N-3-sulfopropyl-N,N-dimethylammonium)ethyl methacrylate) (PSBMA)--grafted onto -quartz substrates in the presence of lysozyme protein. The brush models were developed to closely replicate experimentally synthesized brush samples and to provide detailed insights into structural and dynamical changes at the molecular level during protein adsorption. Using steered molecular dynamics simulations, we show that the PSBMA brush, due to its high local density, exhibits the greatest resistance to protein insertion. C root-mean-square deviation and interaction patterns analyses further reveal that PSBMA also induces the most significant destabilization of lysozyme, while PDMAEMA brush enhances protein stability through ion-mediated interactions. The PNOMA brush, while requiring the lowest force for protein adsorption, induces greater protein destabilization than the PDMAEMA brush primarily due to electrostatic repulsion caused by a short carbon spacer length. To the best of our knowledge, this study presents the first comprehensive and realistic model system--comprising nanomaterials, polymers, and proteins, specifically antifouling polyzwitterions and polyelectrolytes grafted onto -quartz substrates via linkers. These findings highlight the dual role of antifouling polymer brushes: resisting protein adsorption and modulating protein structural dynamics, offering valuable insights for the rational design of next-generation antifouling materials. TOC GRAPHICS O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/651893v1_ufig1.gif" ALT="Figure 1"> View larger version (72K): org.highwire.dtl.DTLVardef@9620b8org.highwire.dtl.DTLVardef@3e395dorg.highwire.dtl.DTLVardef@1282169org.highwire.dtl.DTLVardef@1a997f7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2025

Follistatin-like protein 1 interacts with programmed cell death 4 to promote vascular mimicry in hepatocellular carcinoma by activating the PI3K/AKT/mTOR signaling pathway

Hepatocellular carcinoma (HCC), the most common type of liver cancer, is highly prone to recurrence and metastasis after curative treatment. However, the molecular mechanisms governing these post-management setbacks remain largely unknown. Previous studies found that the high expression of follistatin-like protein 1 (FSTL1) in tumors is implicated in recurrence, metastasis, and poor patient prognosis. In this study, we aimed to investigate the role of FSTL1 in HCC. We found that FSTL1 overexpression was positively correlated with vascular mimicry and poor prognosis. In vitro experiments confirmed that the interaction between FSTL1 and programmed cell death 4 (PDCD4) activates epithelial-to-mesenchymal transition and promotes the proliferation, invasion, and migration of liver cancer cells. The protein-protein interaction between FSTL1 and PDCD4 significantly promotes VM as well as the expression of the pro-angiogenic vascular endothelial growth factor by activating AKT/mTOR signaling. Our data suggest that FSTL1 may be a potential target for the treatment of HCC. Implications: Our findings indicate that the protein FSTL1 may be a novel therapeutic target for managing patients with HCC.

cancer biology↗

bioRxiv2025

A Non-canonical Role for Hepatocyte MLKL in Promoting Mitochondrial Dysfunction and Senescence in the Aging Liver

Liver aging is characterized by chronic inflammation and metabolic dysfunction that contributes to the progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Necroptosis, a form of inflammatory cell death, is activated in aging livers, and genetic (Ripk3-/-or Mlkl-/- mice) or pharmacological (RIPK1 inhibitor necrostatin-1s) inhibition of necroptosis attenuates liver inflammation and pathology. However, the cell type-specific role of necroptosis in liver aging remains unclear. Given that MLKL is expressed in hepatocytes, and its expression increases with age, we generated hepatocyte-specific MLKL-overexpressing mice (MLKLHepOE) to determine its role in liver aging. Unexpectedly, MLKL overexpression in hepatocytes did not induce necroptosis, but instead upregulated markers of cellular senescence (cell cycle arrest genes and SASP factors), increased macrophage infiltration, and elevated M1 macrophage marker expression. Electron microscopy and mitochondrial analyses revealed abnormal mitochondrial morphology, elevated oxidative stress, and disrupted mitochondrial dynamics, while lipidomics demonstrated alterations in hepatic lipid metabolites. In agreement with our observations in MLKLHepOE mice, MLKL overexpression in AML12 hepatocytes impaired mitochondrial respiration, increased proinflammatory extracellular vesicle (EV) release, and induced senescence markers, without triggering cell death. Together, these findings reveal a non-lethal, non-necroptotic role for MLKL in promoting hepatocyte senescence and metabolic dysfunction via mitochondrial impairment and EV-mediated inflammation. Our study highlights MLKL as a novel driver of liver inflammaging and a potential therapeutic target for age-related liver disease.

cell biology↗

bioRxiv2025

Digital Twin Brain Predicts rTMS Effects on Brain State Dynamics in Chronic Tinnitus

Predicting repetitive transcranial magnetic stimulation (rTMS) effects on whole-brain dynamics in clinical populations is crucial for developing personalized therapies and advancing precision medicine in brain disorders. This study provides the first proof-of-concept demonstrating that the Digital Twin Brain (DTB) can forecast rTMS effects on brain state dynamics in individuals with brain disorders (chronic tinnitus). First, we identified two aberrant brain states that predominantly overlapped with the somatomotor and default mode networks, respectively. Subsequently, we developed DTB for patients and derived regional responses for each brain region, revealing distinct roles of the parieto-occipital and frontal regions. Mechanistically, we examined the biological plausibility using tinnitus-specific risk genes and investigated the multi-scale neurobiological relevance. Clinically, we found that DTB can predict rTMS effects in an independent, longitudinal dataset (all r > 0.78). Particularly, the predictive capacity exhibits a state-specific nature. Overall, this work proposes a novel DTB-based framework for predicting rTMS effects in clinical populations and provides the first empirical evidence supporting its clinical utility. This approach may be generalizable to other brain disorders and neuromodulation techniques, promoting broader advancements in brain health.

neuroscience↗

bioRxiv2025

Dual MYC and GSPT1 Protein Degrader for MYC-Driven Cancers

Direct targeting of the oncoprotein MYC has long been attempted in cancer therapy, with limited success. We here identify a novel co-regulatory feedback loop of MYC and G1 to S phase transition protein 1 (GSPT1), where MYC promotes transcription of GSPT1, and GSPT1 senses stop codon of MYC to promote its translation. We report on the first-in-class dual MYC/GSPT1 protein degrader, GT19630. GT19630 significantly induced integrated stress response, abrogated oxidative phosphorylation through inhibition of the TCA cycle and induced cell death. Protein degradation of MYC was critical for efficacy of GT19630. GT19630 induced profound anti-proliferative effects and apoptosis agnostic to TP53 in a broad range of cancer cells, and is highly active in vivo in multiple, therapy-resistant hematologic and solid tumor models. Dual MYC/GSPT1 degradation was well tolerated in humanized CrbnI391V mice. In conclusion, we propose a novel treatment approach by directly targeting the MYC-GSPT1 axis in MYC-driven cancers. Statement of significanceMYC has been considered an undruggable protein. We found a targetable, novel positive co-regulatory feedback of MYC and GSPT1, a key translation terminator. The dual MYC/GSPT1 degrader GT19630 is highly active in MYC-driven tumors, with moderate effects on humanized Crbn mice, providing opportunities to improve treatment outcome of MYC-driven cancers.

cancer biology↗

bioRxiv2025

Exploring Population Differences in the Human Gut Microbiome: from Microbial Abundance to Single Nucleotide Polymorphisms

The human gut microbiota exhibits significant diversity across populations, influenced by factors such as geography, diet, and lifestyle, particularly between the Han Chinese and non-Chinese populations. While previous studies have predominantly focused on the taxonomic abundance of the gut microbiome, the impact of single nucleotide polymorphisms (SNPs) in driving population-specific differences remains largely underexplored. In this study, we systematically investigated gut microbial differences between the Han Chinese and non-Chinese populations using the Human Gut Microbiome Reference Genome Catalog (HGMRGC). HGMRGC includes 271,480 non-redundant genomes from 5,785 prokaryotic species, which was generated by metagenomic sequencing data from 9,320 publicly available samples across 22 countries and 3,584 newly sequenced samples from Han Chinese individuals across 29 provinces and regions in China. We observed geography was the primary driver of microbial variation of abundance and SNPs. We identified 625 novel population-specific genome clusters from HGMRGC with functional differences in carbohydrate utilization and 126 species exhibiting distinct prevalence related to vitamin biosynthesis, antibiotic resistance, and carbohydrate metabolism. Beta diversity analysis highlighted significant inter-population differences in both microbial abundance and SNPs, while alpha diversity analysis revealed that non-Chinese populations exhibited higher diversity in microbial abundance, and Han Chinese populations displayed greater diversity in SNPs. These results provide valuable insights into population-specific microbial diversity, laying the groundwork for future research on its functional and health implications.

microbiology↗

bioRxiv2025

ERK and PKA signaling drive the evolutionary expansion of the cortex

The human cerebral cortex, essential for intelligence, cognition, and language, evolved its uniqueness through mechanisms that drive neuronal expansion. Here, we demonstrate that ERK and PKA signaling cooperatively preserve the neurogenic capacity of cortical radial glia (RGs) by inhibiting gliogenic YAP/TAZ and SHH signaling. YAP/TAZ signaling drives cortical RGs toward ependymal fate, while SHH signaling facilitates the generation of cortical tripotential intermediate progenitor cells that produce cortical astrocytes, oligodendrocytes, and olfactory bulb interneurons. During evolution, cortical outer radial glia (oRGs) acquire dominant ERK/PKA signaling through a self-reinforcing feedback mechanism that suppresses both YAP and SHH pathways, thereby significantly enhancing oRG self-renewal capacity and extending the neurogenic period. These findings reveal that cortical neurogenesis, gliogenesis, and evolutionary expansion are coordinately regulated by an integrated ERK, PKA, YAP/TAZ, and SHH signaling, identifying a unifying principle of mammalian cortical development and evolution.

developmental biology↗

bioRxiv2025

Accurate DNA Methylation Predictor for C9orf72 Repeat Expansion Alleles in the Pathogenic Range

The hexanucleotide (G4C2) repeat expansion in the promoter region of C9orf72 is the most frequent genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). In this study, we conducted a genome-wide DNA methylation (DNAm) analysis using EPIC version 2 (EPICv2) arrays on an FTD cohort comprising 27 carriers and 250 non-carriers of the pathogenic C9orf72 repeat expansion from the Amsterdam Dementia Cohort. We identified differentially methylated CpGs probes associated with the pathogenic C9orf72 expansion and used these findings to create a DNAm Least Absolute Shrinkage and Selection Operator (LASSO) predictor to identify repeat expansion carriers. Eight CpG sites at the C9orf72 locus were significantly differentially hypermethylated in repeat expansion carriers compared to non-carriers. The LASSO model predicted repeat expansion status with an average accuracy of 98.6%. The LASSO predictor was further validated in an independent cohort of 2,548 subjects with available EPICv2 data, identifying four C9orf72 repeat expansion carriers, subsequently confirmed by repeat-primed PCR. This result not only illustrates the accuracy of the DNAm predictor of C9orf72 repeat expansion carriers but also suggests that repeat expansion carriers may be more prevalent than expected. The identification of a highly accurate DNAm biomarker for a repeat expansion locus associated with neurodegenerative disorders may provide great value for studying this locus. The approach holds significant promise for investigating this and other repeat expansion loci, particularly given the growing interest in epigenetic epidemiological studies involving large cohorts with available DNAm data. Graphical abstract (optional) O_FIG O_LINKSMALLFIG WIDTH=155 HEIGHT=200 SRC="FIGDIR/small/643775v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@9d7879org.highwire.dtl.DTLVardef@505560org.highwire.dtl.DTLVardef@154720org.highwire.dtl.DTLVardef@f0c063_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

bioRxiv2025

A novel enterococcus phage endolysin Lys22 with a wide host range against mixed biofilm of Enterococcus faecalis, Staphylococcus aureus and Acinetobacter baumannii

The global surge in multidrug-resistant (MDR) bacterial pathogens has created an urgent imperative for innovative antimicrobial strategies. Enterococcus faecalis, Staphylococcus aureus, and Acinetobacter baumannii demonstrate remarkable antibiotic resistance and dominate hospital-acquired infections. These bacteria often form biofilms, a complex community structure that shields them from immune system phagocytosis, resists antibiotic penetration, and enhances their survival in harsh environments. In clinical cases, these bacteria often form mixed biofilms and lead to treatment failures. Phages and their derivatives have emerged as promising candidates in the fight against drug-resistant bacteria. Lys22, an endolysin derived from an enterococcus phage, has been cloned and demonstrated to possess a broad host range, effectively targeting E. faecalis, various Staphylococcus species, and A. baumannii. When applied to the biofilms formed by these bacteria, Lys22 was found to significantly inhibit both simple and complex biofilms in vitro. Virulent genes, including agrA, sarA, and icaA in S. aureus; asa1, cylA, and hyl in E. faecalis; and OmpA and lpsB in A. baumannii were also downregulated by Lys22. Notably, Lys22 also exhibited a robust protective effect against dual or triple infections involving E. faecalis, S. aureus, and A. baumannii in a zebrafish eggs model, highlighting its potential as a therapeutic agent in combatting multi-bacterial infections.

microbiology↗

bioRxiv2025

Silicon regulation of pectin methyl-esterification and cellulose microfibril organization modulates FERONIA-mediated cell wall integrity signaling for rice adaption to salt stress

The beneficial element silicon (Si) plays a crucial role in mitigating salt stress in plants and can activate intracellular signal transduction pathways that reprogram the transcriptome of salt-stressed plants. However, the mechanisms by which plants perceive Si nutrition, induce the expression of Si-responsive genes, and regulate the activity of Si-responsive proteins remain inadequately understood. In this study, we found that Si enhances cell wall integrity by increasing the degree of pectin methyl-esterification and changing the cellulose microfibril arrangement and functions as a regulatory switch for the activities of cell wall integrity sensors (FER homologs OsFLR1 and OsFLR2) during rice plant adaptation to high salinity. Furthermore, the inhibition of OsFLR1 and OsFLR2 through FER-specific inhibitors could negate the beneficial effects of Si and affect the uptake and accumulation of Si in rice seedlings. In conclusion, these findings suggest that Si signaling initiation involves FER-mediated cell wall integrity signaling pathways during salt stress adaptation in rice.

plant biology↗

bioRxiv2025

Early-peaking caspase-7 activity at the plasma membrane drives apoptotic phosphatidylserine exposure

Apoptosis is an immunologically silent form of regulated cell death executed by caspase1. Caspase cleaves hundreds of substrates throughout the cell to regulate apoptotic processes2, including phosphatidylserine (PS) externalization3-5. However, spatio-temporal regulation of caspase activity in dying cells remains unclear. Here, we show that caspase activity peaks earlier at the plasma membrane (PM) during apoptosis by establishing a Dual Forster resonance energy transfer (Dual FRET) imaging system that combines subcellularly targeted FRET-based caspase biosensors with a cytosolic reference counterpart6,7. Genetic analysis identified caspase-7, an executioner caspase considered an inefficient backup for caspase-3, the major executioner caspase8,9, as a caspase responsible for the Early-Peaking Caspase Activity at the PM (EP-CAP). Mechanistically, EP-CAP is mediated via electrostatic interactions between PS in the inner leaflet of the PM and polybasic residues in the N-terminal intrinsically disordered region (IDR) of caspase-7, which are liberated by the caspase-mediated removal of polyacidic residues. Physiologically, EP-CAP facilitates the efficient cleavage of phospholipid scramblases for the rapid externalization of PS and subsequent efferocytosis. Accordingly, we propose that caspase-7, but not caspase-3, is a bona fide immunologically silent death caspase reinforcing the non-inflammatory nature of apoptosis via EP-CAP.

cell biology↗

bioRxiv2025

Continuous FACS sorting of double emulsion picoreactors with a 3D printed vertical mixer.

High-throughput screening and directed evolution using microfluidic picoreactors have produced high-activity enzymes. In this approach, a substrate is co-encapsulated with a candidate enzyme and individual picoreactors are sorted based on an activity reporter. While many approaches use water-in-oil droplets (single emulsions) for fluorescence-activated droplet sorting (FADS) on custom-fabricated microfluidic devices that require integrated optics and electronics, recent approaches have lowered the engineering barriers to adoption by using simple microfluidic droplet generators to produce water-in-oil-in-water droplets (double emulsion picoreactors, DEs) that can be sorted with commercial FACS (fluorescence-activated cell sorting). Despite the simplified engineering requirements, high variability in loading rates and low yield during loading are barriers to efficient DE FACS sorting. Here, we optimized surfactants to enhance DE stability and demonstrated that a 3D-printed corkscrew on the sample line acts as a vertical mixer to enable more continuous loading. With these optimized loading conditions, we analyzed 1.17 million DEs in four 10-minute sorting rounds with a mean frequency of 480 Hz (390 Hz including sample exchanges); in a mock sort of 10% fluorescent DEs, we achieved 89.2{+/-}1.1% accuracy and 78{+/-}0.9% recovery with our optimized loading protocol. Overall, improved ease-of-use and throughput for FACS sortable DEs should expand the accessibility of directed evolution in controlled in vitro environments.

bioengineering↗

bioRxiv2025

Cell-Type-Specific Surfaceome Profiling of 100-500 Isolated Cells using a Droplet-Based Magnetic Affinity Purification System

Cell surface proteins (CSPs) represent an important source of biomarkers and therapeutic targets. However, due to the inherent sensitivity limitations of existing technologies, tissue and cell-type-specific surfaceomes remain poorly characterized, especially in the context of human diseases. Herein, we develop nanoMAPS (nanoscale Magnetic Affinity Purification System), a miniaturized proteomic sample preparation method for surfaceome profiling of as few as 100-500 cells (1000x to 100,000x lower than existing technologies). We demonstrate that the miniaturization of magnetic bead-based affinity purification inside a single droplet can efficiently improve the recovery of surface proteins and reduce non-specific absorption of intracellular proteins. By applying nanoMAPS to human immune cells isolated from PBMCs, we demonstrate robust identification of both well-known cell-type-specific surface markers and candidate proteins. We establish nanoMAPS as a promising platform to expand surface proteomics from cultured cells to primary cells isolated from patients or mouse models.

systems biology↗

bioRxiv2025

Physical Activity and Depressive Mood Shared the Structural Connectivity between Motor and Reward Network: a population-based study from the UK Biobank

BackgroundExercise has been revealed to leave a positive effect on alleviating depressive symptoms by various existing studies. However, the neural basis behind this phenomenon remains unknown, as well as its underlying biological mechanism.AimsUsing a large neuroimaging cohort from UK Biobank, this study aimed to identify structural connectivity (SC) patterns simultaneously linked with physical activity and depression, as well as its biological interpretation.Method492 participants with major depression disorder (MDD) and 535 healthy controls (HC) were extracted from the UK Biobank dataset. Partial least squares regression was first utilized to explore a replicable SC pattern simultaneously associated with physical activity and depressive mood. The neuromaps toolbox was applied to interpret the biological ontologies of the identified SC pattern. Neuroimaging-transcriptome association and enrichment analyses were conducted to explore its underlying genetic basis, pathways and cell types. The reproducibility and generalizability were tested on another independent MDD dataset (N=3,496) and bipolar disorder (BD) dataset (N=81).ResultsA SC pattern linked with exercise was identified to be both significantly correlated with depressive mood and group discriminative between MDDs and HCs, which primarily located between the motor-related regions and reward-related regions. This pattern was associated with multiple neurotransmitter receptors, such as serotonin and GABA receptors, and enriched in pathways like synaptic signaling and astrocytes cell type. The SC pattern and genetic results were also replicated in another independent MDD dataset and present commonalities with BD.ConclusionsThis study not only initially identified a reproducible shared SC pattern between physical activity and depressive mood, but also elucidated the underlying biological mechanisms, which enhanced our understanding of how exercise helps alleviate depression and may inform the development of novel neuromodulation targets.

neuroscience↗

bioRxiv2025

Quantitative and large-scale investigation of human TCR-HLA Cross-Reactivity

The interaction between Human leukocyte antigens (HLA) and T cell receptor (TCR) is essential for adaptive immune recognition. While it is known that one TCR can map to multiple HLA alleles, the extent of this cross-reactivity remains poorly understood. Here, we introduce THNet, a TCR-based HLA similarity inference method, and performed a comprehensive analysis of HLA-TCR cross-reactivity. This method is built upon clustering over 47 million TCRs to identify over 9 million significant HLA-TCR pairs. We created similarity networks for both class I and class II HLA alleles, illustrating how peptide cross-presentation contributes to HLA-TCR cross-reactivity. This analysis revealed novel disease-susceptibilities missed by single-HLA enrichment analyses, especially in the Black populations. Finally, we demonstrated that THNet prioritized optimal HLA mismatch candidates for organ transplantation, thereby improving patient survival rates. Our investigation of HLA-TCR cross-reactive network might provide useful insights for autoimmune risk prediction and better transplantation outcomes. One Sentence SummaryWe introduced THNet, a large-scale TCR-based HLA similarity mapping network that uncovers previously unrecognized cross-reactivity patterns across HLA alleles and provides valuable insights into their influence on disease susceptibility and graft rejection.

bioinformatics↗

bioRxiv2025

NtLLG4-mediated unconventional polar exocytosis of NtPPME1 coordinates cell wall rigidity and membrane dynamics to control pollen tube integrity

Plant fertilization relies on controlled pollen tube growth that integrates membrane dynamics and cell wall expansion. We previously identified an unconventional exocytic pathway wherein Golgi-derived secretory vesicles (GDSVs) bypass the trans-Golgi network to deliver Nicotiana tabacum pectin methylesterase 1 (NtPPME1), thereby modulating cell wall rigidity. However, the mechanisms linking this patwhay with membrane dynamics and signaling remain elusive. Here, we used cryo-FIB-SEM and 3D tomography to identified GDSVs as a distinct vesicle population at the pollen tube tip. We further demonstrated that tobacco LORELEI-like-GPI-anchored protein 4 (NtLLG4), a key signaling molecule controlling membrane dynamics and integrity, functions as a receptor for NtPPME1, regulating its polar exocytosis via GDSVs to control cell wall stiffness. Furthermore, we identified trafficking signals which direct the unconventional exocytosis of NtPPME1 across intracellular organelles. Our findings reveal a crucial mechanism coupling cell wall rigidity with membrane signaling to control pollen tube growth and integrity during fertilization. TeaserWe reveal a mechanism coupling cell wall rigidity with member signaling to control pollen tube growth and integrity during plant fertilization.

plant biology↗

bioRxiv2025

Dynamic early recruitment of GAK-Hsc70 regulates coated pit maturation

Clathrin-mediated endocytosis (CME) is the process by which clathrin assembles on the plasma membrane to form clathrin-coated pits (CCPs), which then invaginate, accumulate cargo and are released by fission from the membrane to form clathrin-coated vesicles (CCVs). A transition of nascent CCPs from flat-to-curved has been observed by various methods. However, what drives this transition remains unknown and controversial. GAK and its chaperone protein, Hsc70, are well-known to mediate clathrin release from CCVs and several studies have observed a late burst of GAK recruitment as CCVs form. Other studies have proposed that early recruitment of GAK-Hsc70 could function to provide the necessary energy source to remodel nascent flat clathrin lattices, replacing hexagons with pentagons and enabling a gain of curvature and invagination of the growing CCP; however, direct functional evidence is lacking. Here we show that GAK knockdown inhibits CCP formation and invagination. Furthermore, mutations in the J domain of GAK that abolish Hsc70 recruitment to and activation at CCPs, lead to the accumulation of GAK at CCPs, hinder CCP stabilization and invagination and result in a striking increase in the proportion of short-lived, abortive CCPs. These findings support the hypothesis that GAK-Hsc70 promotes the turnover and remodeling of nascent clathrin assemblies required for curvature development during CME. Significance StatementGAK and its chaperone protein, Hsc70, are known to be recruited to clathrin-coated vesicles (CCVs) to mediate clathrin uncoating. Previous studies have proposed that early recruitment of GAK-Hsc70 to CCPs could function to remodel nascent flat clathrin lattices, replacing hexagons with pentagons and enabling a gain of curvature of the assembling polymeric coat. However, there are conflicting views, and direct functional evidence is lacking. Here we show that GAK knockdown inhibits CCP formation and invagination. A detailed domain-specific mutational analysis of GAK pinpointed the importance of J domain-Hsc70 interactions in regulating crucial early steps of CME including CCP stabilization and invagination. These findings support a hypothesis that GAK-Hsc70 promotes turnover of clathrin at nascent CCPs required for curvature development.

cell biology↗