Molecular cloning and characterization of a factor that binds the human glucocorticoid receptor gene and represses its expression.
The human DNA binding factor GRF-1, which associates with the promoter region of the glucocorticoid receptor gene (hGR gene), is a repressor of glucocorticoid receptor transcription. The GRF-1 cDNA was cloned using polyclonal antibodies against the purified protein. The deduced amino acid sequence from the cDNA sequences show the presence of three sequence motifs characteristic of a zinc finger and one motif suggestive of a leucine zipper in which 1 cysteine is found instead of all leucines. The GRF-1 expressed in COS-1 cells has a molecular weight of 95,000 and enhances the homologous down-regulation of wild-type hGR gene expression. Biochemical analysis suggests that GRF-1 interaction is sequence specific and that transcriptional efficacy of GRF-1 is regulated through its interaction with specific sequence motif, namely 5'-GAAGGAGGTAGCGAGAAAAGAAACTG-GAGAAACTCGGT.GG-3'. The GRF-1 mRNA is 6.5 kilobases long in rat liver and human MCF-7 cells, and its level is regulated by glucocorticoids.
LeClerc
S
S
Laboratory of Molecular Endocrinology, Le Centre Hospitalier de l'Université Laval Research Center, Québec, Canada.
Palaniswami
R
R
Xie
B X
BX
Govindan
M V
MV
D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D003850:Deoxyribonuclease I; D019204:GTP-Binding Proteins; D005786:Gene Expression Regulation; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011401:Promoter Regions, Genetic; D011965:Receptors, Glucocorticoid / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D015183:Restriction Mapping; D014158:Transcription, Genetic; D025521:Tumor Suppressor Proteins; D020703:ras GTPase-Activating Proteins; D020666:ras-GRF1
C074560:ARHGAP35 protein, human; C513040:Arhgap35 protein, rat; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; C513039:RASGRF1 protein, human; D011965:Receptors, Glucocorticoid; D012097:Repressor Proteins; D025521:Tumor Suppressor Proteins; D020703:ras GTPase-Activating Proteins; D020666:ras-GRF1; D004247:DNA; D003850:Deoxyribonuclease I; D019204:GTP-Binding Proteins