Regulation of alternative splicing by SRrp86 and its interacting proteins.
SRrp86 is a unique member of the SR protein superfamily containing one RNA recognition motif and two serine-arginine (SR)-rich domains separated by an unusual glutamic acid-lysine (EK)-rich region. Previously, we showed that SRrp86 could regulate alternative splicing by both positively and negatively modulating the activity of other SR proteins and that the unique EK domain could inhibit both constitutive and alternative splicing. These functions were most consistent with the model in which SRrp86 functions by interacting with and thereby modulating the activity of target proteins. To identify the specific proteins that interact with SRrp86, we used a yeast two-hybrid library screen and immunoprecipitation coupled to mass spectrometry. We show that SRrp86 interacts with all of the core SR proteins, as well as a subset of other splicing regulatory proteins, including SAF-B, hnRNP G, YB-1, and p72. In contrast to previous results that showed activation of SRp20 by SRrp86, we now show that SAF-B, hnRNP G, and 9G8 all antagonize the activity of SRrp86. Overall, we conclude that not only does SRrp86 regulate SR protein activity but that it is, in turn, regulated by other splicing factors to control alternative splice site selection.
Li
Jun
J
Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA.
Hawkins
Ian C
IC
Harvey
Christopher D
CD
Jennings
Jennifer L
JL
Link
Andrew J
AJ
Patton
James G
JG
D000251:Adenosine Triphosphatases / Q000378:metabolism; D017398:Alternative Splicing; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D053487:DEAD-box RNA Helicases; D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism; D006801:Humans; D036961:Matrix Attachment Region Binding Proteins / Q000378:metabolism; D051379:Mice; D051839:NFI Transcription Factors; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D011485:Protein Binding; D020365:RNA Helicases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D011960:Receptors, Estrogen; D000068103:Serine-Arginine Splicing Factors; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D036961:Matrix Attachment Region Binding Proteins; D051839:NFI Transcription Factors; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011960:Receptors, Estrogen; C109132:SAFB protein, human; C458841:SREK1 protein, human; C491388:SRSF3 protein, human; C106161:Srsf3 protein, mouse; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D000068103:Serine-Arginine Splicing Factors; D000251:Adenosine Triphosphatases; C102004:DDX17 protein, human; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases