Open AccessOverexpression of the arginine-rich carboxy-terminal region of U1 snRNP 70K inhibits both splicing and nucleocytoplasmic transport of mRNA.
Author(s) -
Joelle Romac,
J. D. Keene
Publication year - 1995
Publication title -
genes and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.136
H-Index - 438
eISSN - 1549-5477
pISSN - 0890-9369
DOI - 10.1101/gad.9.11.1400
Subject(s) - snrnp , rna splicing , biology , spliceosome , sr protein , microbiology and biotechnology , intron , protein splicing , rna binding protein , splicing factor , precursor mrna , nuclear transport , messenger rna , cell nucleus , rna , biochemistry , nucleus , gene
Transient transfection of the U1 snRNP 70K protein into COS cells induced nuclear reorganization and redistribution of the splicing factor SC-35, whereas hnRNP proteins were not affected. Correspondingly, splicing and nucleocytoplasmic transport of a coexpressed mRNA substrate was reduced by overexpression of U1-70K. The carboxy-terminal portion of U1-70K-encompassing repeats of Arg/Ser, Arg/Glu, and Arg/Asp localizes to the nucleus independently of U1 RNA and was responsible for these inhibitory effects. This region of U1-70K contains amino acid residues similar to those found in splicing factors SC-35, U2AF, su(wa), and in other SR proteins suggesting that U1-70K protein may serve as a focus of assembly for functional components of the splicing/transport machinery. These findings are compatible with models that propose that direct interaction between U1-70K and SR proteins play a regulatory role in early events of spliceosome assembly.