The switch in alternative splicing of cyclic AMP-response element modulator protein CREM{tau}2{alpha} (activator) to CREM{alpha} (repressor) in human myometrial cells is mediated by SRp40.
The transcription factor cAMP-response element modulator (CREM) protein, plays a major role in cAMP-responsive gene regulation. Biological consequences resulting from the transcriptional stimuli of CREM are dictated by the expression of multiple protein isoforms generated by extensive alternative splicing of its precursor mRNA. We have previously shown that alternative splicing enables the expression of the CREM gene to be "switched" within the human myometrium during pregnancy from the production of CREMtau(2alpha), a potent transcriptional activator to the synthesis of CREMalpha, a transcriptional repressor. Furthermore we have recently reported that this change in the expression of CREM spliced variants is likely to have important ramifications on the regulation of downstream cAMP-response element-responsive target genes involved in uterine activity during gestation. We have investigated the splicing factors involved in controlling the expression of myometrial CREM splice variants. Data presented here from transient transfections indicate that the switch in the synthesis of CREMtau(2)alpha to CREMalpha that occurs during pregnancy is regulated primarily by an SR protein family member, SRp40. We also show that expression of this splicing factor is tightly regulated in the myometrium during pregnancy. SRp40 regulates the splicing of CREM via its interactions with multiple ESE motifs present in the alternatively exons of CREM. In vitro splicing and electrophoretic mobility shift assays were employed to confirm the functionality of the SRp40-binding ESEs, thus providing a mechanistic explanation of how SRp40 regulates the switch in splicing from production of CREMtau(2)alpha to CREMalpha.
Tyson-Capper
Alison J
AJ
School of Surgical and Reproductive Sciences, 3rd Floor, William Leech Building, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom. A.J.Tyson-Capper@ncl.ac.uk
Bailey
Jarrod
J
Krainer
Adrian R
AR
Robson
Stephen C
SC
Europe-Finner
G Nicholas
GN
D017398:Alternative Splicing; D015153:Blotting, Western; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D051786:Cyclic AMP Response Element Modulator / Q000737:chemistry* / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D003720:Densitometry; D005091:Exons; D005260:Female; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D032342:Muscle Cells / Q000166:cytology; D009215:Myometrium / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D009841:Oligonucleotides / Q000737:chemistry; D010750:Phosphoproteins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000068103:Serine-Arginine Splicing Factors; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection
D018076:DNA, Complementary; D009687:Nuclear Proteins; D009841:Oligonucleotides; D010750:Phosphoproteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D051786:Cyclic AMP Response Element Modulator; D000068103:Serine-Arginine Splicing Factors; D000242:Cyclic AMP