Research square最新文献

{"title":"Genetic Variation Disrupts RNA Structural Repression of Cryptic Splice Sites.","authors":"Jiuyong Xie, Samuel Ogunsola, Jian Yang, Roby Joehanes, Daniel Levy, Chunyu Liu","doi":"10.21203/rs.3.rs-11246309/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11246309/v1","url":null,"abstract":"<p><p>Interpreting how genetic variants alter RNA processing remains a major challenge in human genetics. Using Framingham Heart Study data and genome-wide and mutational analyses, we show that G-tract-disrupting variants activate cryptic 3' splice sites in association with predicted local RNA structural destabilization, while compensatory mutations restoring structural stability re-establish splicing repression. Approximately 1.6 million such sites occur genome-wide, revealing RNA structural disruption as a candidate mechanism of variant-induced cryptic splicing.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692680/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"\"Make sure you involve us\" - Youth experiences, care needs, and areas for intervention across the TB care journey in East Africa: a qualitative study.","authors":"Leslie A Enane, Lameck Diero, Winnie Muyindike, MaKayla Waugh, Kirsten Prabhudas-Strycker, Sylvia Kitur, Julia Omondi, Elyne Rotich, Sarah Namwanje, Lillian Ayesiga, Alexis Byaruhanga, Bob Ssekyanzi, Harold Kooreman, Suzanne Goodrich, Helen Byakwaga, Aggrey Semeere, Neelima Navuluri, Kara Wools-Kaloustian","doi":"10.21203/rs.3.rs-10969224/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-10969224/v1","url":null,"abstract":"<p><p>Background Tuberculosis (TB) is a major cause of morbidity and mortality for youth (ages 15-24) globally. We comprehensively investigated youth experiences, care needs, and areas for intervention across the TB diagnosis, treatment, and post-TB care cascade. Methods Youth with pulmonary TB and healthcare workers providing TB care in Eldoret, Kenya, and Mbarara, Uganda, were purposively sampled. In-depth semi-structured interviews examined factors influencing youth TB care engagement, care needs, and areas for intervention before, during, and after TB treatment. Reflexive thematic analysis was conducted. A youth advisory board supported study implementation. Results We conducted 39 interviews, including 25 healthcare workers and 14 youth with TB. Youth median age was 22, 8 (57%) were male, and one was living with HIV. Youth experiences were driven by poor access to care, including for TB testing, treatment support, and post-TB sequelae. School-related factors included risks for TB acquisition, delayed diagnosis, and barriers to adherence, but also opportunities for treatment support. Stigma and limited TB awareness resulted in delayed diagnosis, inadequate treatment adherence, social isolation, and mental health burdens. Experiences of severe illness, post-treatment morbidity, and TB recurrence impacted physical and mental wellbeing. Treatment support and social support were essential, yet were critically undermined by stigma, economic insecurity, and family circumstances. Areas for intervention centered on accessible, person-centered, youth-friendly care, including after TB treatment. Conclusions Youth and healthcare workers detailed the landscape of gaps in care, opportunities, and solutions for youth with TB. Dedicated youth-led interventions may improve TB care access, outcomes, and quality of life.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692575/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subsecond Terahertz Spectroscopic Mapping of Corneal Hydration Gradients.","authors":"Zachery Harris, Arash Karimi, Sarah Weissbart, Robert Honkanen, M Hassan Arbab","doi":"10.21203/rs.3.rs-11271533/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11271533/v1","url":null,"abstract":"<p><p>Terahertz time-domain spectroscopy (THz-TDS) is sensitive to tissue water content, but slow acquisition and stringent alignment requirements have hindered its <i>in vivo</i> applications, particularly in corneal imaging. We present a compact spherical-scanning THz imaging system that acquires 100-ps time-domain waveforms at a rate of 2 kHz and generates a 10 × 10-pixel image over a 40° × 40° field of view in 0.8 s. Time-of-arrival measurements across the image are used to estimate and automatically correct lateral and axial misalignments. The system was evaluated using a drying contact-lens corneal phantom and seven <i>ex vivo</i> porcine eye globes while sample mass was recorded continuously. In both models, the reflected THz signal exhibited strong correlations with gravimetrically measured hydration changes. Sparse deconvolution of the THz pulses reflected from the contact lens separated echoes from the anterior and posterior interfaces, enabling simultaneous mapping of interfacial reflectivity and optical thickness. The longitudinal sample hydration and optical thickness maps also revealed complementary spatially heterogeneous drying patterns, potentially indicating a limitation of using thickness as a surrogate for hydration evaluation in clinical practice. Finally, we evaluated the sensitivity of THz spectroscopy to hydration change in <i>ex vivo</i> eye globes and found a median 0.7% decrease in THz reflectivity per 1% hydration loss. These results demonstrate rapid, motion-tolerant THz spectral imaging of corneal-scale spherical surfaces and support its further development for noncontact <i>in vivo</i> assessment of corneal hydration.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cell-type-resolved mRNA 3'-end remodeling in Alzheimer's disease.","authors":"Panos Roussos, Yeon Choi, Jaroslav Bendl, Gabriel Hoffman, James Vicari, Prashant N M, Roman Kosoy, Xinyi Wang, Seon Kinrot, Hui Yang, Kiran Girdhar, Donghoon Lee, John Fullard, Pengfei Dong","doi":"10.21203/rs.3.rs-11143166/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11143166/v1","url":null,"abstract":"<p><p>Alternative polyadenylation diversifies messenger RNAs by altering coding sequences and 3' untranslated regions, but its organization across human brain cell types and disruption in neurodegeneration remain poorly understood. By analyzing 3'-capture single-nucleus RNA sequencing data of 6.3 million nuclei from the prefrontal cortex of 1,494 human donors, we defined 108,768 polyadenylation sites across 25,274 genes, most of which were absent from the GENCODE polyadenylation-site annotation. Polyadenylation-site usage was strongly cell-type-specific and revealed regulatory differences not captured by gene expression. With increasing Alzheimer's disease clinicopathological severity, excitatory neurons, oligodendrocytes and immune cells showed increased distal-site preference, including reduced relative usage of intronic sites and increased distal 3' untranslated region usage in synaptic and RNA-processing genes. External single-nucleus data supported neuronal and oligodendrocyte patterns, while complementary analyses of purified microglia supported selected immune-cell findings. Integrative analyses of cleavage and polyadenylation factor expression, co-regulated usage networks, sequence motifs and published perturbations prioritized the cleavage factor Im complex as a candidate regulator. These findings identify cell-type-specific messenger RNA 3'-end remodeling as a reproducible dimension of Alzheimer's disease molecular pathology that is only partly captured by gene-level analyses.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692583/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"1H, 13C, and 15N chemical shift assignments of monomorphic Aβ1-40 at 100 kHz MAS in a diamond rotor.","authors":"Nicolas Matthey, Ravi Shankar Palani, Jiaming Liu, Salima Bahri, Robert Silvers, Brian Michael, Neil Gershenfeld, Sara Linse, Robert G Griffin","doi":"10.21203/rs.3.rs-11089530/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11089530/v1","url":null,"abstract":"<p><p>Amyloid-β (Aβ) fibrils are the principal component of the senile plaques that characterize Alzheimer's disease, and fibrils formed from the Aβ _1-40 alloform are strongly polymorphic, which has long complicated their structural characterization. We recently reported a reproducible, unseeded, monomorphic Aβ _1-40 fibril grown at neutral pH from supersaturated monomer, together with its atomic-resolution structure and its ¹³ C and ¹⁵ N chemical shift assignments (PDB 12GB; BMRB 31300). Here we extend that reference to ¹ H. From a 3D ¹ H-detected hCCH (RFDR) experiment and a 2D hNH experiment recorded at 18.8 T and ω _r /2π = 100 kHz on approximately 0.5 mg of hydrated fibrils packed in a home-built 0.7 mm single-crystal diamond rotor, we assign 123 ¹ H resonances, corresponding close to 90% of the distinct ¹ H sites of the rigid core (residues Q15→V40), together with sixteen ¹ H of the dynamic N-terminal segment. The ¹ H-detected data additionally yield six previously unassigned ¹³ C and three previously unassigned ¹⁵ N resonances, predominantly in aromatic side chains and in the mobile N-terminus, and nine ¹ H- ¹³ C and twenty ¹ H- ¹⁵ N inter-residue contacts that are consistent with the published structure. These assignments provide a residue-level reference for fingerprinting Aβ _1-40 polymorphs and for mapping the binding of antibodies, chaperones and small molecules to this fibril.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692587/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scalable Hydrogel Nanoparticle Enrichment for Enhanced Mass Spectrometry-based Proteomic Analysis of Plasma or Volumetric Dried Blood Samples.","authors":"Amanda Campbell, Lindsey Becker, Simion Kreimer, Mitzi Gonzales, Koen Raedschelders, Jennifer Van Eyk","doi":"10.21203/rs.3.rs-11053241/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11053241/v1","url":null,"abstract":"<p><p>Discovery-based proteomics for translational research requires workflows that reveal deep proteomes with a high degree of analytical precision, are scalable across large sample cohorts, and that can be adapted to different sample matrices. In our work, these sample matrices often extend beyond plasma to include volumetric dried blood samples (VDBS) that offer a minimally invasive alternative to standard venipuncture and enable remote, self-directed sampling. We describe the development and validation of a one-day, 96-well plate-based workflow built on the Ceres Nanotrap Protein Enrichment Affinity (PEAK) nanoparticle platform, optimized independently for both plasma and VDBS ahead of liquid chromatography-tandem mass spectrometry (LC-MS/MS). We benchmarked a tube-based Ceres workflow against both a Seer-encrichment and an unenriched SP3 workflow, assessed its suitability for VDBS, and translated this workflow to a plate-based protocol with a 2-hour digestion. The adapted workflow demonstrated robust reproducibility for both matrices: plasma yielded 4,937 unique proteins with a median inter-day CV of 11% whereas VDBS yielded 3,613 proteins with a median inter-day CV of 19%. Plasma and VDBS proteomes were highly concordant, with 75% of shared proteins quantified within one order of magnitude between matrices. We preliminarily evaluated the biological utility of this platform against a curated panel of 20 Alzheimer's Disease-associated proteins. Our results reveal the Ceres PEAK platform as a flexible, laboratory-adaptable workflow capable of deep and reproducible proteomic profiling of both plasma and VDBS.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692578/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain-Targeted Epigenome-Wide Association Study of Childhood Internalizing and Externalizing Behaviors: Evidence from a Monozygotic Twin Cohort.","authors":"Moira Semple, Taena Hanson, Dominique Hughes, Mary Davis, Kathryn Lemery Chalfant, Candace Lewis","doi":"10.21203/rs.3.rs-11156962/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11156962/v1","url":null,"abstract":"<p><p>Background Identifying biologically meaningful epigenetic signatures of childhood internalizing and externalizing behaviors has been challenging because conventional epigenome-wide association studies are limited by small effect sizes, genetic confounding, and uncertain tissue relevance. We therefore combined a brain-targeted epigenome-wide association study (BEWAS) with a monozygotic twin difference design to improve biological specificity while isolating environmentally driven DNA methylation patterns. Methods Buccal-derived DNA methylation was analyzed in 415 children from the Arizona Twin Project, including 102 monozygotic twin pairs. DNA methylation analyses were restricted to genes with elevated brain expression or established roles in neurotransmission. Linear mixed-effects models were conducted in the full sample, followed by within-pair MZ difference analyses. Nominally associated CpG sites underwent pathway enrichment analyses, and gene-level findings were compared with previous pediatric DNA methylation studies. Results Although no individual CpG sites survived epigenome-wide correction, nominally associated loci converged on robust neurodevelopmental pathways involved in neurogenesis, neuronal differentiation, synaptic organization, and neuronal projection development. Internalizing behaviors demonstrated pathway enrichment in both the population-based and MZ analyses, whereas externalizing enrichment emerged only in the MZ analyses despite the substantially smaller sample size. Gene-level overlap with previous pediatric methylation studies was greater in the MZ analyses, with recurrent associations observed for neurodevelopmental genes including <i>PTPRN2</i> , <i>SHANK2</i> , <i>CACNA1C</i> , and <i>ADCY8</i> . Overall, convergence emerged primarily at the level of genes and biological pathways rather than individual CpG sites. Conclusions These findings suggest that childhood internalizing and externalizing behaviors are characterized by distributed epigenetic regulation across neurodevelopmental systems. More broadly, they demonstrate how biologically informed epigenomic restriction combined with genetically informative study designs can improve detection and interpretation of molecular signatures relevant to developmental psychopathology, providing a foundation for future biomarker discovery and precision mental health approaches.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692597/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuity of Care, Structural Inequities and Neonatal Outcomes among Pregnant Women with Sickle Cell Disease in Uganda: A Mixed-Methods Study.","authors":"Jackline Akello, Savio Mwaka, Annettee Nakimuli, Grace Ndeezi, Musa Sekikubo, Ian Munabi, Ruth Namazzi, Deogratias Munube, David Mukunya, Pebalo Francis, Kenneth Mugabe, Sarah Kiguli, Joseph Rujumba","doi":"10.21203/rs.3.rs-10153606/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-10153606/v1","url":null,"abstract":"<p><p>Pregnancy among women with sickle cell disease (SCD) is high-risk and shaped by clinical vulnerability and systemic barriers. We examined how continuity of care, equity, and social support influence neonatal outcomes and reproductive experiences among women with SCD in Uganda. We conducted a convergent mixed-methods study among 140 enrolled pregnant women with SCD, of whom 135 completed follow-up and were included in the final analysis. Quantitative data included measures of continuity of care (antenatal attendance, follow-up adherence, ease of access), equity indicators (education, employment, marital status, partner support), and clinical vulnerability (haemoglobin, Vaso-occlusive crises). Logistic regression and generalized structural equation modelling assessed associations and mediation. Qualitative data from 34 in-depth interviews and 5 focus group discussions with women and healthcare providers were analysed thematically and integrated with quantitative findings. Continuity of care was strongly protective against adverse fetal or neonatal outcomes (AOR 0.48, 95% CI 0.27-0.87). Adequate antenatal attendance, ease of access, and consistent follow-up adherence were individually protective. Clinical severity, particularly at least three Vaso-occlusive crises, substantially increased risk (AOR 6.33, 95% CI 1.18-33.96). Education, employment, and marital status were not significantly associated with outcomes. Partner support was associated with higher continuity scores (β 0.65, 95% CI 0.13-1.16). Qualitative findings converged with quantitative results, revealing threats to reproductive autonomy, stigma and social abandonment, structural health system barriers (costs, referrals, shortages), and provider moral distress. These systemic constraints undermined care continuity and compounded clinical risk. Continuity of care is a critical protective factor for neonatal outcomes among women with SCD, while socio-demographic advantage alone does not confer protection. Policies should prioritize strengthening care continuity, enhancing social support, and addressing structural health system inequities to improve outcomes in this high-risk population.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692612/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proximity Iodo-labeling of Human Cervical Mucus with an Endogenous Peroxidase.","authors":"John Tsibris","doi":"10.21203/rs.3.rs-11194466/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11194466/v1","url":null,"abstract":"<p><p>A calcium-dependent guaiacol peroxidase (GPx) was detected in the cervix and cervical mucus. Daily measurements of cervical mucus GPx can predict the day of ovulation by 4-5 days, since GPx activity drops significantly as 17beta-estradiol levels peak before ovulation. After ovulation, the concomitant rise of progesterone and GPx mark the end of the optimal time for conception. Cervical mucus was radiolabeled with hydrogen peroxide and Na125I, instead of guaiacol, to detect proteins iodinated by GPx in the follicular and luteal phases of the menstrual cycle. Based on the promising preliminary results, I describe the use of the non-radioactive Na127I and mass spectrometry to detect iodinated peptides and identify the autoiodinated GPx protein and its nearest neighbors. Among them enzymes and signaling proteins will help untie the Gordian knot of multicomponent protein complexes and transient interactions coordinated in the cervix during ovulatory menstrual cycles. Future studies could reveal whether different iodinated mucus proteins and their expression levels are associated with clinical symptoms and conditions during the menstrual cycle prompting research for new markers and therapy targets.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692610/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure of human V-ATPase with the a2-isoform reveals a proton-release gate in the luminal half-channel.","authors":"Stuti Sharma, Caitlin Bricault, Andrew Hillowe, Diksha Parwana, Ivet Bahar","doi":"10.21203/rs.3.rs-11211323/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-11211323/v1","url":null,"abstract":"<p><p>V-ATPases are ATP-dependent proton pumps that acidify intracellular organelles in eukaryotic cells. In mammals, the V0 a-subunit has four isoforms, a1-a4, with a2 enriched in the Golgi and early endosomes. Mutations in a2 are implicated in cutis laxa, male infertility and cancer. Here, we have used cryo-EM to determine the structures of human V-ATPase with the a2-isoform in both the disassembled (a2V0) and assembled (a2V-ATPase) states. We found that in vitro, a2V-ATPase disassembles more readily than a4 containing V-ATPase. The structure of a2V0 allows visualization of proposed lipid binding motifs, a unique luminal extension hypothesized to sense pH in early endosomes, and the location of missense mutations that cause cutis laxa. Most strikingly, the structure of a2 reveals a salt bridge impeding the luminal half-channel that is conserved in vertebrates, but not in yeast. We propose that this salt bridge functions as a gating mechanism to regulate the flow of protons, and thereby V-ATPase activity in higher eukaryotes.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13692625/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149280330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}