Splicing factors SF1 and U2AF associate in extraspliceosomal complexes.

ABSTRACT: Splicing factors SF1 and U2AF associate cooperatively with pre-mRNA and play a crucial role in 3' splice site recognition during early steps of spliceosome assembly. Formation of the active spliceosome subsequently displaces SF1 in a remodeling process that stabilizes the association of U2 snRNP with pre-mRNA. Fluorescence microscopy shows SF1 and U2AF distributed throughout the nucleoplasm, where transcription occurs, with additional concentration in nuclear speckles, where splicing factors accumulate when not engaged in splicing. Fluorescence recovery after photobleaching analysis in live cells shows that the mobilities of SF1 and the two subunits of U2AF (U2AF(65) and U2AF(35)) are correlated with the abilities of these proteins to interact with each other. Direct binding of SF1 to U2AF

SUBMITTER: Rino J 

PROVIDER: S-EPMC2293075 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature