A novel transcriptional coactivator, p52, functionally interacts with the essential splicing factor ASF/SF2.
Increasing evidence suggests that pre-mRNA splicing can take place cotranscriptionally in vivo. However, insight into how these two processes are linked has been lacking. Here, we describe that a novel transcriptional coactivator, p52, interacts not only with transcriptional activators and general transcription factors to enhance activated transcription but also with the essential splicing factor ASF/SF2 both in vitro and in vivo to modulate ASF/SF2-mediated pre-mRNA splicing. Furthermore, immunofluorescence studies indicate that the majority of endogenous p52 is colocalized with ASF/SF2 in the nucleoplasm of HeLa cells. Together, these observations suggest that, in addition to functioning as a transcriptional coactivator, p52 may also act as an adaptor to coordinate pre-mRNA splicing and transcriptional activation of class II genes.
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Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA. geh@box-g.nih.gov
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Wolffe
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D048868:Adaptor Proteins, Signal Transducing; D002474:Cell-Free System; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D009687:Nuclear Proteins / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D016601:RNA-Binding Proteins; D000068103:Serine-Arginine Splicing Factors; D016329:Sp1 Transcription Factor / Q000494:pharmacology; D015534:Trans-Activators / Q000378:metabolism* / Q000494:pharmacology; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation / Q000187:drug effects
D048868:Adaptor Proteins, Signal Transducing; D009687:Nuclear Proteins; C504649:PSIP1 protein, human; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D000068103:Serine-Arginine Splicing Factors