秀丽隐杆线虫中帕夏（Pasha）和德罗沙（Drosha）对于微处理器定位及功能的相互依赖性

Interdependence of Pasha and Drosha for localization and function of the Microprocessor in C. elegans.

作者信息

Knittel Thiago L, Montgomery Brooke E, Reed Kailee J, Chong Madeleine C, Isolehto Ida J, Cafferty Erin R, Smith Margaret J, Sprister Reese A, Magelky Colin N, Scherman Hataichanok, Ketting René F, Montgomery Taiowa A

机构信息

Department of Biology, Colorado State University, Fort Collins, CO, USA.

Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO, USA.

出版信息

Nat Commun. 2025 Jul 1;16(1):5595. doi: 10.1038/s41467-025-60721-5.

DOI:10.1038/s41467-025-60721-5

PMID:40595566

Abstract

Primary microRNA (pri-miRNA) transcripts are processed by the Microprocessor, containing the ribonuclease Drosha and its RNA-binding partner DGCR8/Pasha. In a forward genetic screen utilizing a fluorescence-based sensor that monitors pri-miRNA processing in live Caenorhabditis elegans, we identify a mutation in the conserved G179 residue adjacent to the namesake W180 of Pasha's WW domain that disrupts pri-miRNA processing. We show that both the G179 and W180 residues are required for Pasha dimerization and Microprocessor assembly. The WW domain also facilitates nuclear localization of Pasha, likely through its role in Microprocessor assembly, which in turn promotes nuclear enrichment of Drosha. Furthermore, depletion of Pasha mislocalizes Drosha to the cytoplasm, and vice versa, while deletion of Pasha's N-terminus causes both proteins to accumulate in nucleoli. Our results reveal a mutual dependency between Pasha and Drosha for their localization in C. elegans and highlight the role of Pasha's WW domain in maintaining Microprocessor integrity.

摘要

初级微小RNA（pri-miRNA）转录本由微处理器进行加工，微处理器包含核糖核酸酶Drosha及其RNA结合伴侣DGCR8/Pasha。在一项正向遗传学筛选中，我们利用一种基于荧光的传感器监测秀丽隐杆线虫活体中的pri-miRNA加工过程，鉴定出Pasha的WW结构域中与同名的W180相邻的保守G179残基发生突变，该突变破坏了pri-miRNA的加工。我们发现G179和W180残基都是Pasha二聚化和微处理器组装所必需的。WW结构域还促进Pasha的核定位，可能是通过其在微处理器组装中的作用，这反过来又促进了Drosha的核富集。此外，Pasha的缺失会使Drosha错误定位于细胞质，反之亦然，而删除Pasha的N端会导致两种蛋白质在核仁中积累。我们的结果揭示了Pasha和Drosha在秀丽隐杆线虫中的定位相互依赖，并突出了Pasha的WW结构域在维持微处理器完整性中的作用。