A conserved Drosophila transportin-serine/arginine-rich (SR) protein permits nuclear import of Drosophila SR protein splicing factors and their antagonist repressor splicing factor 1.

ABSTRACT: Members of the highly conserved serine/arginine-rich (SR) protein family are nuclear factors involved in splicing of metazoan mRNA precursors. In mammals, two nuclear import receptors, transportin (TRN)-SR1 and TRN-SR2, are responsible for targeting SR proteins to the nucleus. Distinctive features in the nuclear localization signal between Drosophila and mammalian SR proteins prompted us to examine the mechanism by which Drosophila SR proteins and their antagonist repressor splicing factor 1 (RSF1) are imported into nucleus. Herein, we report the identification and characterization of a Drosophila importin beta-family protein (dTRN-SR), homologous to TRN-SR2, that specifically interacts with both SR proteins and RSF1. dTRN-SR has a broad localization in the cytoplasm and the nucleus, where

SUBMITTER: Allemand E 

PROVIDER: S-EPMC117325 | biostudies-literature | 2002 Jul

REPOSITORIES: biostudies-literature