U1A及其互作蛋白CPL1/FRY2响应盐胁迫的转录后调控机制

盐胁迫影响植物生长发育和生态适应性。申请人近期研究发现剪接体特异性蛋白U1A调控ACO1的剪接从而影响植物耐盐性。然而，植物中如何调控U1A蛋白，以及U1A蛋白是否调控共转录剪接、无义介导的mRNA降解和选择性多聚腺苷化尚不明确。申请人前期工作通过酵母双杂交筛选到U1A互作蛋白CPL1/FRY2，且CPL1/FRY2介导U1A去磷酸化修饰影响U1A的细胞核定位。在此基础上，本项目综合运用phos-tag、RNA-蛋白酵母三杂交、RNA免疫沉淀和染色质免疫共沉淀等技术明确U1A和CPL1/FRY2的互作关系，解析U1A和CPL1/FRY2协同调控共转录剪接、无义介导的mRNA降解和选择性多聚腺苷化的分子机制。旨在揭示植物剪接体参与调控盐胁迫应答的机制，完善植物盐胁迫转录后调控网络，为培育新型耐盐植物提供新的潜在靶标和探索角度。

Salt stress seriously affects plant growth and ecological adaptability. Our previous research showed that the spliceosomal specific protein U1A regulated the splicing of ACO1 and thus affected the plant salt resistance. However, how U1A protein is regulated in planta, and whether U1A protein regulates co-transcriptional splicing, nonsense-mediated mRNA decay (NMD) and alternative polyadenylation (APA) remains unknown. Our preliminary work identified the U1A interacting protein CPL1/FRY2 through yeast two-hybrid, and U1A dephosphorylation affected its nuclear localization mediated by CPL1/FRY2. According to these data, we firstly clarify the interaction between U1A and CPL1/FRY2, and then explore the molecular mechanisms of co-transcriptional splicing, NMD and APA by using phos-tag, RNA-protein yeast three-hybrid, RNA immunoprecipitation and chromatin immunoprecipitation technology. Collectively, our study will reveal the molecular mechanism of plant spliceosome involvement in the post-transcriptional regulation of salt stress, and provide new insights and potential targets for salt-resistant crop breeding.