Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA.
FEBS Lett. 2019 May;593(10):1102-1112. doi: 10.1002/1873-3468.13391. Epub 2019 Apr 29.
The Paip2 protein is a factor regulating mRNA translation and stability in the cytoplasm. It has also been found in the nuclei of several cell types in Drosophila. Here, we aim to elucidate the functions of Paip2 in the cell nucleus. We find that nuclear Paip2 is a component of an ~300-kDa protein complex. Paip2 interacts with mRNA capping factor and factors of RNA polymerase II (Pol II) transcription initiation and early elongation. Paip2 functionally cooperates with the Cbp80 subunit of the cap-binding complex, with both proteins ensuring proper Pol II C-terminal domain (CTD) Ser5 phosphorylation at the promoter. Thus, Paip2 is a novel player at the stage of mRNA capping and early Pol II elongation.
Paip2 蛋白是一种在细胞质中调节 mRNA 翻译和稳定性的因子。它也在果蝇的几种细胞类型的细胞核中被发现。在这里，我们旨在阐明 Paip2 在细胞核中的功能。我们发现核 Paip2 是一个~300kDa 大小的蛋白质复合物的组成部分。Paip2 与 mRNA 加帽因子以及 RNA 聚合酶 II（Pol II）转录起始和早期延伸的因子相互作用。Paip2 与帽结合复合物的 Cbp80 亚基在功能上相互协作，这两种蛋白都确保了 Pol II C 末端结构域（CTD）在启动子处 Ser5 的正确磷酸化。因此，Paip2 是 mRNA 加帽和早期 Pol II 延伸阶段的一个新的参与者。
