The regulation of MS-KIF18A expression and cross talk with estrogen receptor.
This study provides a novel view on the interactions between the MS-KIF18A, a kinesin protein, and estrogen receptor alpha (ERalpha) which were studied in vivo and in vitro. Additionally, the regulation of MS-KIF18A expression by estrogen was investigated at the gene and protein levels. An association between recombinant proteins; ERalpha and MS-KIF18A was demonstrated in vitro in a pull down assay. Such interactions were proven also for endogenous proteins in MBA-15 cells were detected prominently in the cytoplasm and are up-regulated by estrogen. Additionally, an association between these proteins and the transcription factor NF-kappaB was identified. MS-KIF18A mRNA expression was measured in vivo in relation to age and estrogen level in mice and rats models. A decrease in MS-KIF18A mRNA level was measured in old and in OVX-estrogen depleted rats as compared to young animals. The low MS-KIF18A mRNA expression in OVX rats was restored by estrogen treatment. We studied the regulation of MS-KIF18A transcription by estrogen using the luciferase reporter gene and chromatin immuno-precipitation (ChIP) assays. The luciferase reporter gene assay demonstrated an increase in MS-KIF18A promoter activity in response to 10(-8) M estrogen and 10(-7)M ICI-182,780. Complimentary, the ChIP assay quantified the binding of ERalpha and pcJun to the MS-KIF18A promoter that was enhanced in cells treated by estrogen and ICI-182,780. In addition, cells treated by estrogen expressed higher levels of MS-KIF18A mRNA and protein and the protein turnover in MBA-15 cells was accelerated. Presented data demonstrated that ERalpha is a defined cargo of MS-KIF18A and added novel insight on the role of estrogen in regulation of MS-KIF18A expression both in vivo and in vitro.
Zusev
Margalit
M
Department of Cell and Developmental Biology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Benayahu
Dafna
D
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers; D005786:Gene Expression Regulation; D006801:Humans; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D020239:Receptor Cross-Talk; D011960:Receptors, Estrogen / Q000378:metabolism*
D017931:DNA Primers; D012333:RNA, Messenger; D011960:Receptors, Estrogen; C502735:KIF18A protein, human; D016547:Kinesins