Conserved structure, regulatory elements, and transcriptional regulation from the GATA-1 gene testis promoter.
Transcription factor GATA-1 was first identified in erythroid cells, but was later shown to also be expressed in Sertoli cells of the mouse testis. GATA-1 transcription in testis initiates from a different first exon (exon IT) than the erythroid mRNA (transcribed from exon IE). To begin to address the question of how expression of GATA-1 might be differentially regulated in Sertoli and erythroid cells, we have cloned and determined the structure of the IT promoters of both the rat and mouse GATA-1 genes. The transcription regulatory mechanism(s) controlling the synthesis of exon IT-derived mRNA was investigated by transfection of wild-type and mutant reporter genes, with and without co-transfected GATA factor expression plasmids, into either fibroblasts or Sertoli cell lines. Two GATA binding sites in the IT promoter were found to be required for GATA factor-mediated activation in fibroblasts: GATA-IT-directed reporter gene expression was activated only after co-transfection with GATA-1, implying that transcriptional activation of GATA-1 in the testis might be at least partially mediated through these GATA regulatory elements. We also found that the endogenous GATA-1 gene was silent in primary culture and two different Sertoli cell lines, and that the repression of co-transfected GATA-1 reporter genes could not be relieved by forced expression of GATA-1 in Sertoli cells. Thus the GATA-IT promoter may be under the control of a regulatory network in Sertoli cells which involves both positive and negative regulation of transcription, and conserved GATA motifs found in the IT promoter may be required for transducing these effects.
Onodera
K
K
Department of Biochemistry, Tohoku University, School of Medicine, Sendai.
Yomogida
K
K
Suwabe
N
N
Takahashi
S
S
Muraosa
Y
Y
Hayashi
N
N
Ito
E
E
Gu
L
L
Rassoulzadegan
M
M
Engel
J D
JD
Yamamoto
M
M
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001853:Bone Marrow / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D050981:Erythroid-Specific DNA-Binding Factors; D005091:Exons; D050982:GATA1 Transcription Factor; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D011401:Promoter Regions, Genetic; D051381:Rats; D012708:Sertoli Cells / Q000737:chemistry*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D016335:Zinc Fingers / Q000235:genetics*
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494689:Gata1 protein, mouse; C494690:Gata1 protein, rat; D009687:Nuclear Proteins; D014157:Transcription Factors; D008156:Luciferases