Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.
Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA 91766, USA.
Plant Physiol. 2023 Aug 31;193(1):537-554. doi: 10.1093/plphys/kiad352.
Cleavage and polyadenylation specificity factor (CPSF) is a protein complex that plays an essential biochemical role in mRNA 3'-end formation, including poly(A) signal recognition and cleavage at the poly(A) site. However, its biological functions at the organismal level are mostly unknown in multicellular eukaryotes. The study of plant CPSF73 has been hampered by the lethality of Arabidopsis (Arabidopsis thaliana) homozygous mutants of AtCPSF73-I and AtCPSF73-II. Here, we used poly(A) tag sequencing to investigate the roles of AtCPSF73-I and AtCPSF73-II in Arabidopsis treated with AN3661, an antimalarial drug with specificity for parasite CPSF73 that is homologous to plant CPSF73. Direct seed germination on an AN3661-containing medium was lethal; however, 7-d-old seedlings treated with AN3661 survived. AN3661 targeted AtCPSF73-I and AtCPSF73-II, inhibiting growth through coordinating gene expression and poly(A) site choice. Functional enrichment analysis revealed that the accumulation of ethylene and auxin jointly inhibited primary root growth. AN3661 affected poly(A) signal recognition, resulted in lower U-rich signal usage, caused transcriptional readthrough, and increased the distal poly(A) site usage. Many microRNA targets were found in the 3' untranslated region lengthened transcripts; these miRNAs may indirectly regulate the expression of these targets. Overall, this work demonstrates that AtCPSF73 plays important part in co-transcriptional regulation, affecting growth, and development in Arabidopsis.
剪接多聚腺苷酸化特异性因子（CPSF）是一种在 mRNA 3'端形成中发挥重要生化作用的蛋白复合物，包括多聚腺苷酸化信号识别和在多聚腺苷酸化位点切割。然而，在多细胞真核生物中，其在生物体水平上的生物学功能大多未知。由于拟南芥（Arabidopsis thaliana）AtCPSF73-I 和 AtCPSF73-II 纯合突变体的致死性，植物 CPSF73 的研究受到了阻碍。在这里，我们使用 poly(A) 标签测序来研究 AtCPSF73-I 和 AtCPSF73-II 在经疟原虫 CPSF73 特异性抗疟药物 AN3661 处理的拟南芥中的作用，该药物与植物 CPSF73 同源。在含有 AN3661 的培养基上直接进行种子萌发是致命的；然而，用 AN3661 处理的 7 天大的幼苗存活下来。AN3661 靶向 AtCPSF73-I 和 AtCPSF73-II，通过协调基因表达和多聚腺苷酸化位点选择抑制生长。功能富集分析表明，乙烯和生长素的积累共同抑制主根生长。AN3661 影响多聚腺苷酸化信号识别，导致 U 丰富信号使用减少，引起转录通读，并增加远端多聚腺苷酸化位点使用。在延长的 3'UTR 中发现了许多 microRNA 靶标；这些 miRNA 可能间接调节这些靶标的表达。总的来说，这项工作表明 AtCPSF73 在共转录调控中发挥重要作用，影响拟南芥的生长和发育。
