GATA-6 is a novel transcriptional repressor of the human Tenascin-C gene expression in fibroblasts

In this study we show that GATA-6 is a novel repressor of TN-C gene expression. We demonstrated that overexpression of GATA-6 in fibroblasts inhibited basal levels, as well as markedly decreased IL-4- and TGF-beta-induced TN-C mRNA and protein levels. A GATA-6 response element was mapped to position -467 to -460 of the TN-C promoter. In addition, we showed that GATA-6 binds this site both in vitro and in vivo.     

The yeast putative transcriptional repressor RGM1 is a proline-rich zinc finger protein

I have cloned a yeast gene, RGM1, which encodes a proline-rich zinc, finger protein. rgm1 mutants do not show any obvious phenotype but overexpression of RGM1 gene greatly impairs cell growth. The proline-rich region of RGM1 attached to a heterologous DNA binding domain is able to repress the expression of the target gene. RGM1 shares similar zinc finger motifs with the mammalian Egr (early growth response) proteins as well as proline-rich sequences with a high serine and threonine content, suggesting that RGM1 and Egr proteins could have functional similarities.     

Regulation of rat growth hormone receptor gene expression

A cDNA encoding the growth hormone (GH) receptor was cloned from rat liver. Both the nucleotide and translated amino acid sequence share greater than 70% similarity with the GH receptors from rabbit and human. An RNA probe was generated from this sequence for use in a solution hybridization assay to quantitate GH receptor mRNA expression in rat tissues. Expression was detected in 9/12 tissues examined, with the highest levels observed in the liver. Expression in liver, kidney, heart and muscle was developmentally regulated, being low at birth and rising to adult levels in 5 weeks. No difference was observed between hepatic expression in males and females, although livers from pregnant rats had elevated levels. Hypophysectomy and GH treatment did not affect hepatic GH receptor mRNA levels.