- Publication date : 2003-10-20
Tremblay JJ, Viger RS. A mutated form of steroidogenic factor 1 (SF-1 G35E) that causes sex reversal in humans fails to synergize with transcription factor GATA-4. J. Biol. Chem. 2003;278:42637-42. doi: 10.1074/jbc.M305485200. PubMed PMID: 12907682.
animals anti-mullerian hormone cell line dna-binding proteins disorders of sex development drug synergism fushi tarazu transcription factors gata4 transcription factor glycoproteins homeodomain proteins humans male mice mutation, missense promoter regions, genetic protein binding rats receptors, cytoplasmic and nuclear steroidogenic factor 1 testicular hormones transcription factors transcription, genetic transfection
Steroidogenic factor 1 (SF-1) is a transcription factor belonging to the nuclear receptor superfamily. SF-1 regulates the expression of many genes involved in reproduction, steroidogenesis, and sexual differentiation. An important SF-1 target for male sexual differentiation is the gene encoding the Müllerian-inhibiting substance hormone that induces regression of the Müllerian ducts in the developing male embryo. Not long ago, a mutation (G35E) in the human SF-1 gene was identified as the cause of sex reversal and adrenal failure in a phenotypically female but genotypically XY individual. This suggested that the mutated SF-1 protein might interfere with the expression of SF-1 target gene(s) involved in the male sexual differentiation pathway, such as MIS. Surprisingly, the initial biochemical characterization of the SF-1 G35E mutant revealed that it could bind and activate the MIS promoter as efficiently as wild-type SF-1. MIS expression, however, does not rely solely on SF-1 but rather requires the concerted action of several transcription factors including GATA-4. We have previously reported that GATA-4 and SF-1 transcriptionally cooperate to synergistically activate the MIS promoter. Thus, we hypothesized that the phenotype observed with the SF-1 G35E mutation could be explained, at least in part, by a failure and/or a disruption of GATA-4/SF-1 synergism. We found that the SF-1 G35E mutant failed to synergize with GATA-4 despite a direct physical interaction between the two proteins. Interestingly, the SF-1 G35E mutant also disrupted transcriptional synergism between wild-type SF-1 and GATA-4, indicating that it could act as a dominant negative competitor. Thus, our results strengthen the importance of a GATA-4/SF-1 cooperation for MIS transcription and reveal that disruption of this synergism might be responsible for some cases of abnormal sex differentiation in humans.