p54nrb/NonO and PSF promote U snRNA nuclear export by accelerating its export complex assembly

作者：Izumi Hiroto; McCloskey Asako; Shinmyozu Kaori; Ohno Mutsuhito^*

来源：Nucleic Acids Research, 2014, 42(6): 3998-4007.

DOI：10.1093/nar/gkt1365

The assembly of spliceosomal U snRNPs in metazoans requires nuclear export of U snRNA precursors. Four factors, nuclear cap-binding complex (CBC), phosphorylated adaptor for RNA export (PHAX), the export receptor CRM1 and RanGTP, gather at the m(7)G-cap-proximal region and form the U snRNA export complex. Here we show that the multifunctional RNA-binding proteins p54nrb/NonO and PSF are U snRNA export stimulatory factors. These proteins, likely as a heterodimer, accelerate the recruitment of PHAX, and subsequently CRM1 and Ran onto the RNA substrates in vitro, which mediates efficient U snRNA export in vivo. Our results reveal a new layer of regulation for U snRNA export and, hence, spliceosomal U snRNP biogenesis.

• 单位
  RIKEN