GATA transcription factors and fat cell formation.

GATA transcription factors play important roles in a variety of developmental processes. Recently, we discovered that GATA factors also play a key role in adipogenesis. Two isoforms, GATA-2 and GATA-3, are specifically expressed in murine preadipocytes but not mature adipocytes. Continuous expression of GATA factors in preadipocyte cell lines inhibits terminal differentiation into mature adipocytes. In contrast, GATA-3-deficient mouse embryonic stem cells possess a higher capacity to convert to adipocytes. The inhibitory effect of GATA on adipogenesis is mediated in part by suppression of promoters of adipogenic factors, including peroxisome proliferator-activated receptor gamma, but additional mechanisms are also likely to be in effect. These findings indicate that GATA factors function as molecular gatekeepers at the onset of terminal adipocyte differentiation. Whether GATA factors are also involved in the commitment of multipotent mesenchymal stem cells to progenitors of the adipogenic lineage is under investigation.