Sudo Haruka, Nozaki Aya, Uno Hideaki, Ishida Yo-Ichi, Nagahama Masami
Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan.
FEBS Lett. 2016 Sep;590(17):2963-72. doi: 10.1002/1873-3468.12314. Epub 2016 Aug 6.
In yeast, the Trf4/5-Air1/2-Mtr4 polyadenylation (TRAMP) complex acts as a cofactor for the nuclear exosome to promote degradation of various RNAs. However, the corresponding machinery in mammals is less characterized. We analyzed the interactions of the human TRAMP-like proteins, PAPD5, ZCCHC7, and MTR4, with the nuclear exosome. PAPD5 and ZCCHC7 exhibited mutual interactions in presence of the exosome catalytic subunit RRP6, whereas MTR4 was dispensable for their assembly. Furthermore, the human TRAMP-like proteins were involved in the RRP6-catalyzed turnover of pre-rRNA 5'ETS fragments. These results suggest the significant role for RRP6 in the assembly of TRAMP-like proteins during nucleolar RNA surveillance.
在酵母中，Trf4/5-Air1/2-Mtr4多聚腺苷酸化（TRAMP）复合体作为核外切体的辅因子，促进各种RNA的降解。然而，哺乳动物中的相应机制却鲜为人知。我们分析了人类TRAMP样蛋白PAPD5、ZCCHC7和MTR4与核外切体的相互作用。在核外切体催化亚基RRP6存在的情况下，PAPD5和ZCCHC7表现出相互作用，而MTR4对它们的组装并非必需。此外，人类TRAMP样蛋白参与了RRP6催化的前体rRNA 5'ETS片段的周转。这些结果表明RRP6在核仁RNA监测过程中TRAMP样蛋白的组装中发挥着重要作用。
