Sperm motility and morphology are indispensable for sperm-egg interaction and successful fertilization.However,the RNA splicing mechanisms in an m6A-dependent manner regulating spermiogenesis-related genes remain poor...Sperm motility and morphology are indispensable for sperm-egg interaction and successful fertilization.However,the RNA splicing mechanisms in an m6A-dependent manner regulating spermiogenesis-related genes remain poorly defined,and targeted therapy strategies to restore impaired sperm motility and morphology are lacking.In this study,we identify heterogeneous nuclear ribonucleoprotein R(hnRNPR)as a critical m6A-dependent splicing mediator.Pathogenic mutations in HNRNPR cause sperm motility decline,morphological abnormality,and male infertility in both humans and mice.Mechanistically,Hnrnpr mutation disrupts m6A-dependent splicing of Skap2 pre-mRNA,thus impairing cytoskeletal structure and mitochondrial organization in sperm.Consistently,specific knockout of Skap2 in male germ cells displays sperm abnormalities,which phenocopy those observed in humans and mice with Hnrnpr mutants,unveiling a functional hnRNPR-SKAP2 axis.Leveraging these insights,we developed a therapeutic strategy to restore sperm motility and morphology,relying on extracellular vesicle-mediated SKAP2 delivery to enter the efferent ductules of the testicles,which could promote sperm cytoskeletal remodeling and mitochondrial organization.Notably,the co-culture of extracellular vesicle SKAP2 with human and mouse sperms also significantly enhanced the sperm motility.Altogether,these findings identify hnRNPR as a pivotal regulator of m6A-mediated Skap2 splicing during spermiogenesis and highlight extracellular vesicle SKAP2 as a promising therapeutic target for poor sperm quality and male infertility.展开更多
Chromosome segregation in mitosis is orchestrated by the dynamic interactions between the kinetochore and spindle microtubules.Our recent studies show that mitotic motor CENP-E cooperates with SKAP and forms a link be...Chromosome segregation in mitosis is orchestrated by the dynamic interactions between the kinetochore and spindle microtubules.Our recent studies show that mitotic motor CENP-E cooperates with SKAP and forms a link between kinetochore core MIS13 complexand spindle microtubule plus-ends to achieve accurate chromosome alignment in mitosis. However, it remains elusive how SKAP regulates kinetochore attachment from lateral association to end-on attachment during metaphase alignment. Here, we identify a novel interaction between Aurora B and SKAP that orchestrates accurate interaction between the kinetochore and dynamic spindle microtubules. Interestingly, SKAP spontaneously phase-separates in vitro via weak, multivalent interactions into droplets with fast internaldynamics. SKAP and Aurora B form heterogeneous coacervates in vitro, which recapitulate the dynamics and behavior of SKAP cometsin vivo. Importantly, SKAP interaction with Aurora B via phase separation is essential for accurate chromosome segregation and alignment. Based on those findings, we reason that SKAP–Aurora B interaction via phase separation constitutes a dynamic pool of Aurora Bactivity during the lateral to end-on conversion of kinetochore–microtubule attachments to achieve faithful cell division.展开更多
基金supported by the National Natural Science Foundation of China(82088102)CAMS Innovation Fund for Medical Sciences(2019-I2M-5-064)+5 种基金Collaborative Innovation Program of Shanghai Municipal Health Commission(2020CXJQ01)Key Discipline Construction Project(2023-2025)of Three-Year Initiative Plan for Strengthening Public Health System Construction in Shanghai(GWVI-11.1-35)Shanghai Clinical Research Center for Gynecological Diseases(22MC1940200)Shanghai Urogenital System Diseases Research Center(2022ZZ01012)Shanghai Frontiers Science Research Center of Reproduction and Development,the Shenzhen portion of the Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone(program grant#HZQSWS-KCCYB2024031)China Postdoctoral Science Foundation under Grant Number 2025M782263。
文摘Sperm motility and morphology are indispensable for sperm-egg interaction and successful fertilization.However,the RNA splicing mechanisms in an m6A-dependent manner regulating spermiogenesis-related genes remain poorly defined,and targeted therapy strategies to restore impaired sperm motility and morphology are lacking.In this study,we identify heterogeneous nuclear ribonucleoprotein R(hnRNPR)as a critical m6A-dependent splicing mediator.Pathogenic mutations in HNRNPR cause sperm motility decline,morphological abnormality,and male infertility in both humans and mice.Mechanistically,Hnrnpr mutation disrupts m6A-dependent splicing of Skap2 pre-mRNA,thus impairing cytoskeletal structure and mitochondrial organization in sperm.Consistently,specific knockout of Skap2 in male germ cells displays sperm abnormalities,which phenocopy those observed in humans and mice with Hnrnpr mutants,unveiling a functional hnRNPR-SKAP2 axis.Leveraging these insights,we developed a therapeutic strategy to restore sperm motility and morphology,relying on extracellular vesicle-mediated SKAP2 delivery to enter the efferent ductules of the testicles,which could promote sperm cytoskeletal remodeling and mitochondrial organization.Notably,the co-culture of extracellular vesicle SKAP2 with human and mouse sperms also significantly enhanced the sperm motility.Altogether,these findings identify hnRNPR as a pivotal regulator of m6A-mediated Skap2 splicing during spermiogenesis and highlight extracellular vesicle SKAP2 as a promising therapeutic target for poor sperm quality and male infertility.
基金supported in part by grants from the National Natural Science Foundation of China(32090040,31621002,21922706,91854203,91853115,81630080,31430054,31471275,31871359,31970655,and 31671405)the National Key Research and Development Program of China(2017YFA0503600,2016YFA0100500,and 2017YFA0102900)+3 种基金the Ministry of Education(IRT_17R102)The Strategic Priority Research Program of Chinese Academy of Sciences(XDB19000000)the Fundamental Research Funds for the Central Universities(WK2070000066 and WK2070000194)National Institutes of Health Grants(CA164133,DK115812,and DK56292).
文摘Chromosome segregation in mitosis is orchestrated by the dynamic interactions between the kinetochore and spindle microtubules.Our recent studies show that mitotic motor CENP-E cooperates with SKAP and forms a link between kinetochore core MIS13 complexand spindle microtubule plus-ends to achieve accurate chromosome alignment in mitosis. However, it remains elusive how SKAP regulates kinetochore attachment from lateral association to end-on attachment during metaphase alignment. Here, we identify a novel interaction between Aurora B and SKAP that orchestrates accurate interaction between the kinetochore and dynamic spindle microtubules. Interestingly, SKAP spontaneously phase-separates in vitro via weak, multivalent interactions into droplets with fast internaldynamics. SKAP and Aurora B form heterogeneous coacervates in vitro, which recapitulate the dynamics and behavior of SKAP cometsin vivo. Importantly, SKAP interaction with Aurora B via phase separation is essential for accurate chromosome segregation and alignment. Based on those findings, we reason that SKAP–Aurora B interaction via phase separation constitutes a dynamic pool of Aurora Bactivity during the lateral to end-on conversion of kinetochore–microtubule attachments to achieve faithful cell division.
