Hyponastic Leaves 1 protects pri-miRNAs from nuclear exosome attack
Shuai Gao, Jingyu Wang, Ning Jiang, Shiting Zhang, Yuan Wang, Jun Zhang, Ning Li, Yixiao Fang, Yang Lin, Susu Chen, Bingbing Yan, Tian Huang, Benke Kuai, Yingxiang Wang, Fang Chang, Guodong Ren
Abstract
Significance MicroRNAs (miRNAs) are indispensable regulators of gene expression. Hyponastic Leaves 1 (HYL1) is a core component of the microprocessor that processes primary miRNAs (pri-miRNAs) into mature miRNAs. Here we report a noncanonical function of HYL1 in protecting pri-miRNAs from unwanted nuclear exosome activities during processing. Our observations also suggest that HYL1 may contribute differently to the Dicer-like 1 (DCL1)-mediated maturation of loop-to-base– and base-to-loop–processed pri-miRNAs. This study thus integrates the RNA surveillance system to the miRNA biogenesis pathway and sheds light on the multifaced roles of HYL1 in miRNA biogenesis.