Extending the L1 region in canonical double-stranded RNA-binding domains impairs their functions  

作　　者：Xiaoxiao Zhang Peng Li Huanhuan Zhong Fanming Yang Fanzhou Liu Gabriel Yedid Yan Zeng 

机构地区：[1]Department of Zoology,College of Life Sciences,Nanjing Agricultural University,Nanjing 210095,China

出　　处：《Acta Biochimica et Biophysica Sinica》2021年第4期463-471,共9页生物化学与生物物理学报（英文版）

基　　金：This work was supported in part by the grants from the National Natural Science Foundation of China(Nos.31470435 and 31570843).

摘　　要：A large number of proteins involved in RNA metabolism possess a double-stranded RNA-binding domain(dsRBD),whose sequence variations and functional versatilities are still being recognized.All dsRBDs have a similar structural fold:α1-L1-β1-L2-β2-L3-β3-L4-α2(αrepresents anα-helix,βaβ-sheet,and L a loop conformation between the well-defined secondary structures).Our recent work revealed that the dsRBD in Drosha,which is involved in animal microRNA(miRNA)biogenesis,differs from other dsRBDs by containing a short insertion in its L1 region and that this insertion is important for Drosha function.We asked why the same insertion is excluded in all other dsRBDs and proposed that a longer L1 may be detrimental to their functions.In this study,to test this hypothesis,we inserted the Drosha sequence into several well-known dsRBDs from various organisms.Gel mobility shift assay demonstrated that L1 extension invariably reduced RNA binding by these dsRBDs.In addition,such a mutation in Dicer,another protein involved in miRNA biogenesis,impaired Dicer’s ability to process miRNAs,which led to de-repression of reporter expression,in human cells.Taken together,our results add to the growing appreciation of the diversity in dsRBDs and suggest that dsRBDs have intricate structures and functions that are sensitive to perturbations in the L1 region.

关 键 词：double-stranded RNA-binding domain DROSHA microRNA DICER 

分 类 号：Q51[生物学—生物化学]