In the fission yeast Schizosaccharomyces pombe,Mei2,an RNA-binding protein essential for entry into meiosis,regulates meiosis initiation.Mei2 binds to a specific non-coding RNA species,meiRNA,and accumulates at the sm...In the fission yeast Schizosaccharomyces pombe,Mei2,an RNA-binding protein essential for entry into meiosis,regulates meiosis initiation.Mei2 binds to a specific non-coding RNA species,meiRNA,and accumulates at the sme2 gene locus,which encodes meiRNA.Previous research has shown that the Mei2 C-terminal RNA recognition motif(RRM3)physically interacts with the meiRNA 5'region in vitro and stimulates meiosis in vivo.However,the underlying mechanisms still remain elusive.We first employed an in vitro crosslinking and immunoprecipitation sequencing(CLIP-seq)assay and demonstrated a preference for U-rich motifs of meiRNA by Mei2 RRM3.We then solved the crystal structures of Mei2 RRM3 in the apo form and complex with an 8 mer RNA fragment,derived from meiRNA,as detected by in vitro CLIP-seq.These results provide structural insights into the Mei2 RRM3-meiRNA complex and reveal that Mei2 RRM3 binds specifically to the Uuc(U)sequence.Furthermore,a structure-based Mei2 mutation,Mei2F644A causes defective karyogamy,suggesting an essential role of the RNA-binding ability of Mei2 in regulating meiosis.展开更多
基金This work was financially supported by grants from the Ministry of Science and Technology of China(2019YFA0508403)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB39010300)+2 种基金the National Natural Science Foundation of China(32090040,31870760,32171222,92149302,U1932122,and 32100958)the China Postdoctoral Science Foundation(2019M662182)the Fundamental Research Funds for the Central Universities(WK2340000097).
文摘In the fission yeast Schizosaccharomyces pombe,Mei2,an RNA-binding protein essential for entry into meiosis,regulates meiosis initiation.Mei2 binds to a specific non-coding RNA species,meiRNA,and accumulates at the sme2 gene locus,which encodes meiRNA.Previous research has shown that the Mei2 C-terminal RNA recognition motif(RRM3)physically interacts with the meiRNA 5'region in vitro and stimulates meiosis in vivo.However,the underlying mechanisms still remain elusive.We first employed an in vitro crosslinking and immunoprecipitation sequencing(CLIP-seq)assay and demonstrated a preference for U-rich motifs of meiRNA by Mei2 RRM3.We then solved the crystal structures of Mei2 RRM3 in the apo form and complex with an 8 mer RNA fragment,derived from meiRNA,as detected by in vitro CLIP-seq.These results provide structural insights into the Mei2 RRM3-meiRNA complex and reveal that Mei2 RRM3 binds specifically to the Uuc(U)sequence.Furthermore,a structure-based Mei2 mutation,Mei2F644A causes defective karyogamy,suggesting an essential role of the RNA-binding ability of Mei2 in regulating meiosis.
