Splicing factors SRp20 and 9G8 promote the nucleocytoplasmic export of mRNA.
We have uncovered a novel function for two members of the SR protein family in mRNA export. Using UV cross-linking, transient transfection, and Xenopus oocyte microinjection, we find that the nucleocytoplasmic shuttling proteins SRp20 and 9G8 interact specifically with a 22-nt RNA element from the histone H2a gene to promote the export of intronless RNAs in both mammalian cells and Xenopus oocytes. Antibodies to SRp20 or 9G8 eliminate RNA binding and significantly inhibit the export of RNAs carrying the element from oocyte nuclei. Our observation that SRp20 and 9G8 can be UV cross-linked to polyadenylated RNA in both the nucleus and cytoplasm of HeLa cells suggests a more general role for these SR proteins in mRNA export.
Huang
Y
Y
Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06536, USA.
Steitz
J A
JA
D021581:Active Transport, Cell Nucleus / Q000502:physiology*; D000818:Animals; D000918:Antibody Specificity; D019556:COS Cells; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008322:Mammals; D009500:Neutralization Tests; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D009865:Oocytes / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors; D014981:Xenopus
D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C491388:SRSF3 protein, human; D000068103:Serine-Arginine Splicing Factors