title: Functional cooperation between GATA factors and cJUN on the star promoter in MA-10 Leydig cells.
abstract: Steroid hormone biosynthesis requires the steroidogenic acute regulatory  protein (STAR). STAR is part of a protein complex that transports cholesterol  through the mitochondrial membrane where steroidogenesis begins. Several  transcription factors participate to direct the proper spatiotemporal and  hormonal regulation of the Star gene in Leydig cells.  Mechanistically, this is believed to involve the functional interplay between  many of these factors. Here we report a novel transcriptional cooperation  between GATA factors and cJUN on the mouse Star and human  STAR promoters in MA-10 Leydig cells. This cooperation was observed  with different GATA members (GATA1, 4, and 6), whereas only cJUN could  cooperate with GATA factors. GATA/cJUN transcriptional cooperation on the  Star promoter is mediated via closely juxtaposed GATA and AP-1  binding motifs. Mutation of all functional GATA and cJUN elements abolished  GATA/cJUN cooperation, which is in agreement with previous data reporting a  direct interaction between GATA4 and cJUN in a heterologous system. These data  add valuable new insights that further define the molecular mechanisms that  govern Star transcription in steroidogenic cells of the testis.
authors.affiliation: Reproduction, Perinatal, and Child Health, CHUQ Research Centre, 2705 Laurier Blvd, Quebec City, Quebec, Canada .
authors.forename: Luc J
authors.initials: LJ
authors.lastname: Martin
authors.forename: Francis
authors.initials: F
authors.lastname: Bergeron
authors.forename: Robert S
authors.initials: RS
authors.lastname: Viger
authors.forename: Jacques J
authors.initials: JJ
authors.lastname: Tremblay
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D050980:GATA Transcription Factors / Q000378:metabolism*; D006801:Humans; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D010750:Phosphoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D017931:DNA Primers; D050980:GATA Transcription Factors; D010750:Phosphoproteins; D016755:Proto-Oncogene Proteins c-jun; D000098682:Steroidogenic Acute Regulatory Protein