PHAX, a mediator of U snRNA nuclear export whose activity is regulated by phosphorylation

被引：285

作者：

Ohno, M ^{[1
]}

Segref, A ^{[1
]}

Bachi, A ^{[1
]}

Wilm, M ^{[1
]}

Mattaj, IW ^{[1
]}

机构：

[1] European Mol Biol Lab, D-69117 Heidelberg, Germany

来源：

CELL | 2000年 / 101卷 / 02期

关键词：

D O I：

10.1016/S0092-8674(00)80829-6

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

In metazoa, assembly of spliceosomal U snRNPs requires nuclear export of U snRNA precursors. Export depends upon the RNA cap structure, nuclear cap-binding complex (CBC), the export receptor CRM1/Xpo1, and RanGTP. These components are however insufficient to support U snRNA export. We identify PHAX (phosphorylated adaptor for RNA export) as the additional factor required for U snRNA export complex assembly in vitro. In vivo, PHAX is required for U snRNA export but not for CRM1-mediated export in general. PHAX is phosphorylated in the nucleus and then exported with RNA to the cytoplasm, where it is dephosphorylated. PHAX phosphorylation is essential for export complex assembly while its dephosphorylation causes export complex disassembly. The compartmentalized PHAX phosphorylation cycle can contribute to the directionality of export.

引用

页码：187 / 198

页数：12

共 51 条

[1] Identification of a nuclear export receptor for tRNA [J].