PNAS nexus最新文献_第3页

Animal-origin-free culture improves mitotic response for chromosome aberration analysis of human peripheral blood. 无动物源培养提高了人外周血染色体畸变分析的有丝分裂反应。

IF 3.8

PNAS nexus Pub Date : 2026-04-15 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag120

Yohei Fujishima, Donovan Anderson, Shara Kamakura, Renya Saito, Yuki Tsushima, Ayaka Okimoto, Valerie Swee Ting Goh, Tomisato Miura

{"title":"Animal-origin-free culture improves mitotic response for chromosome aberration analysis of human peripheral blood.","authors":"Yohei Fujishima, Donovan Anderson, Shara Kamakura, Renya Saito, Yuki Tsushima, Ayaka Okimoto, Valerie Swee Ting Goh, Tomisato Miura","doi":"10.1093/pnasnexus/pgag120","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag120","url":null,"abstract":"The lymphocyte culture method for chromosomal aberration analysis was established in the 1960s, and culture media supplemented with fetal bovine serum (FBS) have been routinely used. However, issues such as lot-to-lot variability, potential contamination risks, and the growing demand for animal-origin-free (AOF) systems have created a need for reliable alternatives. This study evaluated the suitability of serum-free culture media for human peripheral blood chromosome analysis under both clinical-cytogenetic and cytogenetic biodosimetry settings, including the dicentric chromosome (Dic) assay and the cytokinesis-block micronucleus (MN) assay. Cell proliferation markers of mitotic index (MI), binucleated cell frequency, and chromosomal aberration frequencies were compared between conventional RPMI 1640 medium and human plasma-like medium, each tested with or without FBS supplementation in phytohemagglutinin-stimulated blood cultures. Serum-free media demonstrated significantly higher MI values than in RPMI 1640-containing FBS, suggesting that serum supplementation may inhibit cell-cycle progression in 48- and 72-h cultures. While MI increased, the frequencies of Dics and MNs in serum-free conditions were not significantly different from those observed in serum-supplemented cultures. These findings indicate that serum supplementation may not be essential for blood culture media in human peripheral blood chromosome analysis, supporting the transition toward serum-free and AOF systems in cytogenetic applications.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag120"},"PeriodicalIF":3.8,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13123523/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791656","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}

引用次数: 0

Combined administration of interleukin-2 and 18 with anti-PD-L1 antibody induces CCL5-positive CD8 T cells to suppress liver tumors. 白细胞介素-2和白细胞介素- 18联合抗pd - l1抗体可诱导ccl5阳性CD8 T细胞抑制肝脏肿瘤。

IF 3.8

PNAS nexus Pub Date : 2026-04-15 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag113

Masamichi Kimura, Kenzaburo Yamaji, Kenichi Harada, Hideya Kawaji, Jun Imamura, Haruki Okamura, Yoshimasa Tanaka, Michinori Kohara, Kiminori Kimura

{"title":"Combined administration of interleukin-2 and 18 with anti-PD-L1 antibody induces CCL5-positive CD8 T cells to suppress liver tumors.","authors":"Masamichi Kimura, Kenzaburo Yamaji, Kenichi Harada, Hideya Kawaji, Jun Imamura, Haruki Okamura, Yoshimasa Tanaka, Michinori Kohara, Kiminori Kimura","doi":"10.1093/pnasnexus/pgag113","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag113","url":null,"abstract":"Remarkable progress has been made in cancer immunotherapy, partly because of the development of immune checkpoint inhibitors. However, their efficacy varies across cancer types, with limited response observed in solid tumors, such as hepatocellular carcinoma (HCC). The primary cause of this low efficacy is insufficient infiltration of effector cells, such as cytotoxic CD8+ T cells, into the tumor tissue. This study investigated whether recombinant interleukin (rIL)-2, rIL-18, and antiprogrammed cell death-ligand 1 (αPD-L1) antibody (Ab) could serve as novel immunotherapies for HCC. Multidrug resistance gene 2-deficient mice, a spontaneously occurring liver cancer model associated with aging, were administered rIL-2, rIL-18, and αPD-L1Ab. Antitumor effects were evaluated using computed tomography and serum alpha-fetoprotein levels. Significant tumor shrinkage was observed in the rIL-2+rIL-18+αPD-L1Ab group, but not in the rIL-2+αPD-L1Ab or rIL-18+αPD-L1Ab groups. Concurrent administration of αCD8-neutralizing antibody abolished the antitumor effect, indicating CD8+ T-cell dependency. Spatial gene expression profiling revealed that intratumoral CD8+ effector T cells express and secrete CCL5 after treatment, promoting CD8+ T-cell mobilization to the liver and enhancing antitumor efficacy. Pretreatment with a CCL5 neutralizing antibody suppressed CD8+ cell infiltration into the tumor, eliminating the antitumor effect. The triple combination therapy used in this study promotes the infiltration and maintenance of CD8+ T cells in the liver, suggesting a promising new immunotherapy for HCC.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag113"},"PeriodicalIF":3.8,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13096734/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791685","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}

引用次数: 0

Crystal structure of epidermal growth factor domain-specific O-linked N-acetylglucosamine transferase reveals a conserved N-R-R constellation for uridine diphosphate recognition in the GT61 family. 表皮生长因子结构域特异性o -连接n-乙酰氨基葡萄糖转移酶的晶体结构揭示了GT61家族中尿苷二磷酸识别的保守N-R-R星座。

IF 3.8

PNAS nexus Pub Date : 2026-04-15 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag115

Yuko Tashima, Masamichi Nagae, Jiaoyang Jiang, Tetsuya Okajima

{"title":"Crystal structure of epidermal growth factor domain-specific O-linked N-acetylglucosamine transferase reveals a conserved N-R-R constellation for uridine diphosphate recognition in the GT61 family.","authors":"Yuko Tashima, Masamichi Nagae, Jiaoyang Jiang, Tetsuya Okajima","doi":"10.1093/pnasnexus/pgag115","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag115","url":null,"abstract":"Epidermal growth factor (EGF) domain-specific O-linked N-acetylglucosamine transferase (EOGT), a glycosyltransferase (GT) 61 family member, catalyzes O-N-acetylglucosamine (O-GlcNAc) transfer from uridine diphosphate (UDP)-GlcNAc to serine or threonine residues within EGF domains in the endoplasmic reticulum. In this study, we determined the crystal structure of the EOGT-UDP complex and identified the critical residues mediating their interactions, which were validated via site-directed mutagenesis and enzyme activity assays. These residues were conserved in EOGT orthologs across metazoans, and UDP binding occurred independently of divalent metal ions and the canonical Asp-X-Asp motif. Although EOGT catalyzes O-GlcNAcylation, similar to O-GlcNAc transferase (OGT), it shares little sequence similarity with OGT and belongs to a distinct GT family. Instead, EOGT is more closely related to protein O-linked-mannose β1,4-N-acetylglucosaminyltransferase 2 (POMGNT2). Structural comparison with POMGNT2 revealed a conserved triad of one asparagine and two arginine residues, the N-R-R constellation. These elements were conserved across metazoans and green plants (Viridiplantae), suggesting a unifying mechanism of UDP recognition and providing a framework to interpret disease-associated EOGT mutations and assess the evolution of catalytically active GT61 family enzymes.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag115"},"PeriodicalIF":3.8,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13123520/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791668","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}

引用次数: 0

Neurodivergent influenceability in agentic AI as a contingent solution to the AI alignment problem. 代理人工智能中的神经发散影响能力作为人工智能对齐问题的偶然解决方案。

IF 3.8

PNAS nexus Pub Date : 2026-04-14 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag076

Alberto Hernández-Espinosa, Felipe S Abrahão, Olaf Witkowski, Hector Zenil

{"title":"Neurodivergent influenceability in agentic AI as a contingent solution to the AI alignment problem.","authors":"Alberto Hernández-Espinosa, Felipe S Abrahão, Olaf Witkowski, Hector Zenil","doi":"10.1093/pnasnexus/pgag076","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag076","url":null,"abstract":"Ensuring that AI systems, including artificial general intelligence and artificial superintelligence, behave in alignment with human values and interests presents significant challenges and is known as the AI alignment problem. As AI advances, concerns about control and existential risks become increasingly relevant. Here, we introduce the concept of agentic influenceability, behavioral neurodivergent diversity, opinion attack, associated opinion, and influenceability scores, and a mathematical proof of the inevitability of misalignment and the impossibility of full orchestrated controllability of agentic systems based on formal undecidability and irreducibility arguments. We explore whether embracing this inevitable misalignment can foster a dynamic ecosystem of adversarial and collaborative AI agents without central orchestration, which itself would constitute another agent, while still offering some degree of soft controllability. The investigation demonstrates that misalignment in foundation models can serve as a counterbalancing mechanism, enabling cooperation among agents most aligned with human interests to prevent divergent dominance by any single agent. Experiments with large language models show that open models exhibit greater behavioral diversity, whereas proprietary models, constrained by artificial guardrails, display more limited controllability. The findings advocate for neurodivergent influenceability as a contingent response to mathematically uncontrollable misalignment, leveraging agent divergence to improve AI safety.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag076"},"PeriodicalIF":3.8,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13077672/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147694003","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}

引用次数: 0

Extreme heat reduces and reshapes urban mobility. 极端高温减少并重塑了城市交通。

IF 3.8

PNAS nexus Pub Date : 2026-04-14 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag078

Andrew Renninger, Carmen Cabrera

{"title":"Extreme heat reduces and reshapes urban mobility.","authors":"Andrew Renninger, Carmen Cabrera","doi":"10.1093/pnasnexus/pgag078","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag078","url":null,"abstract":"Extreme heat is a problem in Southern European countries and cities, aggravated by rising temperatures and aging populations. Research on mobility during extreme heat remains limited to small samples and geographic contexts, leaving gaps in our systematic understanding of how populations adjust their day-to-day mobility patterns and how these adaptations vary across social groups. Here, we use mobile phone data from passive and active mobile network connections covering 13 million individuals in Spain (27% of the population) to examine extreme heat's impact on mobility at scale. We stratify by age, gender, economic class, and type of activity. Our findings show mobility falls by as much as 10% on hot days generally and 20% on hot afternoons specifically, when temperatures peak. Further differences emerge on hot days. Older adults cut travel to work and other activities, while those earning less are less able to avoid work; social mixing declines and spatial structure changes as activity falls in city centers. These disruptions have implications for urban economies, as curbed activity and interaction could threaten the dynamism of cities as hubs of social and economic exchange.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag078"},"PeriodicalIF":3.8,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13077673/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147693931","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}

引用次数: 0

Correction to: Conditions for the stable adsorption of lipid monolayers to solid surfaces. 修正：脂质单分子层在固体表面稳定吸附的条件。

IF 3.8

PNAS nexus Pub Date : 2026-04-13 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag098

引用次数: 0

Causal effect of school-entry age on long-run family formation: Quasi-experimental evidence from 14 million individuals in Vietnam. 入学年龄对长期家庭形成的因果影响：来自越南1400万人的准实验证据。

IF 3.8

PNAS nexus Pub Date : 2026-04-10 eCollection Date: 2026-05-01 DOI: 10.1093/pnasnexus/pgag119

Ishaan Busireddy, Janny Liao, Dat Hoang Vu, Tam Ngo Minh Tran, Jan-Walter De Neve

{"title":"Causal effect of school-entry age on long-run family formation: Quasi-experimental evidence from 14 million individuals in Vietnam.","authors":"Ishaan Busireddy, Janny Liao, Dat Hoang Vu, Tam Ngo Minh Tran, Jan-Walter De Neve","doi":"10.1093/pnasnexus/pgag119","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag119","url":null,"abstract":"School-entry age has been suggested to affect human capital development. Little is known, however, about the impacts of school-entry age on long-run outcomes, particularly in lower-income countries where most children and adolescents worldwide reside. We exploit a natural experiment based on school-entry rules in Vietnam to examine the causal effect of school-entry age on educational outcomes and family formation. Data on children's school-entry age, education, childbearing, marriage, and mortality in the next generation are extracted from the longitudinal Young Lives study conducted between 2001 and 2016 (n = 10,746) and the Population and Housing Censuses of 1989, 1999, and 2009 (n = 14,251,279). In adolescence, children who enter school at an older age stay in school longer and delay childbearing and marriage. In adulthood, women who enter school at an older age are 3.1 percentage points less likely to have given birth (P < 0.001, 95% CI: 3.0-3.3), have 0.1 fewer children (P < 0.001, 95% CI: 0.09-0.10), are 2.4 percentage points less likely to marry (P < 0.001, 95% CI: 2.3-2.5), and are 8% less likely (0.4 percentage points, P < 0.001, 95% CI: 0.3-0.5) to experience the death of a child. Decomposition analyses suggest that incapacitation mechanisms may play a larger role in shaping family formation outcomes than human capital pathways. These findings demonstrate how subtle shifts in early institutional timing can have profound and enduring impacts, with implications for education, health, and social policy globally.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 5","pages":"pgag119"},"PeriodicalIF":3.8,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13147269/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147847206","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}

引用次数: 0

Reversible and causal epigenetic information loss in liver aging and disease. 肝脏衰老和疾病的可逆和因果表观遗传信息丢失。

IF 3.8

PNAS nexus Pub Date : 2026-04-10 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag109

Roni B Shtark, Naor Sagy, Noga Korenfeld, Maayan Gal, Ido Goldstein, Daniel Z Bar

{"title":"Reversible and causal epigenetic information loss in liver aging and disease.","authors":"Roni B Shtark, Naor Sagy, Noga Korenfeld, Maayan Gal, Ido Goldstein, Daniel Z Bar","doi":"10.1093/pnasnexus/pgag109","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag109","url":null,"abstract":"The loss of epigenetic information has been proposed as a driver of aging and diseases, but the reversibility and causality of this process remain underexplored. Here, we analyze liver-unique methylation sites-genomic loci that show distinct methylation patterns in the liver compared to other tissues. Upon disease progression, these sites overwhelmingly regress toward the pan-tissue average. In addition, we demonstrate that this regression also occurs in a majority of these sites during normal aging. Using causal sites previously identified by Mendelian randomization analysis, we identify significant enrichment of liver-unique methylation sites in causal aging-associated loci, particularly sites that are highly methylated in healthy liver. Remarkably, repeated fasting, a metabolic intervention known to improve liver function, partially restores the DNA accessibility patterns at these sites. This restoration also occurs in isolated hepatocytes subjected to fasting-mimicking conditions, suggesting the effect is cell-autonomous rather than due to changes in tissue composition. The liver-unique methylation sites are enriched for binding sites of key metabolic transcription factors and show significant overlap with genetic variants associated with liver disease risk, suggesting a mechanistic link between epigenetic information loss and liver dysfunction. Our findings establish epigenetic information loss as both a marker and mediator of liver aging and disease, while demonstrating its potential reversibility through metabolic interventions.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag109"},"PeriodicalIF":3.8,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13101997/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791676","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}

引用次数: 0

Molecular basis for alternative charge separation pathways in type-II photosynthetic reaction centers. ii型光合反应中心电荷分离途径的分子基础。

IF 3.8

PNAS nexus Pub Date : 2026-04-09 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag111

Tomoyasu Noji, Keisuke Saito, Hiroyuki Tamura, Hiroshi Ishikita

{"title":"Molecular basis for alternative charge separation pathways in type-II photosynthetic reaction centers.","authors":"Tomoyasu Noji, Keisuke Saito, Hiroyuki Tamura, Hiroshi Ishikita","doi":"10.1093/pnasnexus/pgag111","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag111","url":null,"abstract":"In photosynthetic reaction centers from purple bacteria, bacteriochlorophyll a (the special pair PAPB and accessory bacteriochlorophyll BA) and bacteriopheophytin a (HA) form the active electron-transfer branch and uniquely contain a polar methyl-keto (3-acetyl) group. However, despite its importance in defining local polarity, even the currently available highest-resolution structures (∼2 Å) cannot unambiguously distinguish the methyl carbon from the keto oxygen, limiting insight into its functional role. Here, we investigate how the methyl-keto orientations of the PB and HA cofactors influence the energetics of charge-separated intermediates, using a quantum mechanical/molecular mechanical approach. We identify two kinetically isolated, metastable methyl-keto conformations of PB, Tyr-OH…BA and Tyr-OH…PB, each associated with a distinct charge-separation pathway: the canonical [PAPB]* → [PAPB]•+BA •- and alternative BA* → BA •+HA •- pathways, respectively. For HA, methyl-keto reorientation stabilizes HA •- when forward transfer to the primary quinone (QA) is inhibited. These results show that distinct methyl-keto conformations selectively tune charge-separation routes while also contributing to the oxidative robustness of bacteriochlorin macrocycles.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag111"},"PeriodicalIF":3.8,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112432/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791699","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}

引用次数: 0

Structural and biochemical basis of ROC-dependent activation of LRRK2. roc依赖性LRRK2活化的结构和生化基础。

IF 3.8

PNAS nexus Pub Date : 2026-04-09 eCollection Date: 2026-04-01 DOI: 10.1093/pnasnexus/pgag112

Yangshin Park, Chunxiang Wu, Kayla Tennessen, Li Wan, Neo C Hoang, Cardea W Hoang, Jingling Liao, Quyen Q Hoang

{"title":"Structural and biochemical basis of ROC-dependent activation of LRRK2.","authors":"Yangshin Park, Chunxiang Wu, Kayla Tennessen, Li Wan, Neo C Hoang, Cardea W Hoang, Jingling Liao, Quyen Q Hoang","doi":"10.1093/pnasnexus/pgag112","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgag112","url":null,"abstract":"Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson's disease, yet the molecular mechanism governing LRRK2 activation remains incompletely understood. LRRK2 is a large multidomain enzyme whose kinase activity is regulated by intramolecular interactions and by its Ras of complex proteins (ROC) GTPase domain. Here, we combine cryo-electron microscopy, X-ray crystallography, and structure-guided biochemical perturbations to define how ROC conformational switching regulates LRRK2 activation. Cryo-EM reconstructions reveal that monomeric full-length LRRK2 samples three distinct conformational states-autoinhibited, intermediate, and activated-indicating that large-scale activation-associated rearrangements can occur through an intrinsic intramolecular pathway, independently of Rab29 binding, higher-order oligomerization, or membrane association. A 1.6-Å crystal structure of an extended ROC construct reveals intrinsic conformational plasticity within the GTPase switch regions that likely underlies these transitions. Structure-guided disulfide engineering identifies a functional coupling between residue R1441 and switch II that directly modulates GTPase activity in both isolated ROC and full-length LRRK2. Disruption of this coupling phenocopies the disease-associated R1441H mutation. Together, these findings establish ROC as a dynamic conformational engine that drives a multistep intramolecular activation mechanism in LRRK2, providing mechanistic insight into how pathogenic mutations promote aberrant kinase activation.","PeriodicalId":74468,"journal":{"name":"PNAS nexus","volume":"5 4","pages":"pgag112"},"PeriodicalIF":3.8,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13102002/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147791064","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}

引用次数: 0