Expression of human myometrial G alpha s messenger ribonucleic acid transcript during pregnancy and labour: involvement of alternative splicing pathways.
We have shown previously that expression of 46 and 54 kDa human myometrial G alpha s protein isoforms is increased during gestation and then subsequently decreased during labour. These proteins appear to be coded for by G alpha s-Small (with a serine residue at position 72) and G alpha s-Large (with a serine residue at position 87) mRNA splice variants respectively. In the study presented here we have used a G alpha s cDNA template to generate [32P]cytidine cRNA riboprobes for use in RNase protection assays, so as to measure total myometrial G alpha s mRNA levels in relation to the pattern of expression of G alpha s mRNA splice variants during pregnancy and labour. We report that total levels of human myometrial G alpha s mRNA remain similar in non-pregnant and pregnant women but are substantially reduced during parturition. Our data also provide strong evidence that alternative splicing of G alpha s precursor mRNA has a primary role in regulating expression of G alpha s protein isoforms during pregnancy and labour. The inclusion of an additional serine codon in G alpha s mRNAs during pregnancy involves a switch in alternative splicing pathways. We speculate that this switch may be due to a change in specificity of splicing factors that are modulated during pregnancy and labour.
Europe-Finner
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Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, UK.
Phaneuf
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Cartwright
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Mardon
H J
HJ
López Bernal
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A
D000328:Adult; D017398:Alternative Splicing; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D007743:Labor, Obstetric; D008875:Middle Aged; D009215:Myometrium / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D011247:Pregnancy / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics*
D012333:RNA, Messenger; D019204:GTP-Binding Proteins