11075815

pubmed:Citation

11

We have recently demonstrated that a testicular GATA-binding protein, GATA-1, up-regulates the transcription of inhibin alpha-subunit gene through interaction with GATA motifs in the promoter region in MA-10, a mouse Leydig tumor cell line. In this study, we showed that both GATA-1 and GATA-4 also transactivated the transcription from the promoter for the 4.8-kb inhibin/activin beta-B-subunit gene transcripts, beta-B(4.8)-subunit promoter, in two testicular cell lines, MA-10 and MSC-1, which is a mouse Sertoli cell line. The abilities of GATA-1 and GATA-4 interacting with GATA and/or GATA-like sequences to transactivate the beta-B(4.8)-subunit promoter were next examined by mutation analysis. Mutations of GATA or GATA-like sequences caused no apparent effect or only a small decrease in the basal transcriptional activity of this promoter. However, mutation of the GATA motif at -65 markedly decreased 60-70% of the effect of GATA-1 on the transactivation of beta-B(4.8)-subunit promoter in both MA-10 and MSC-1 cells. In addition, mutation of the GATA motif in MSC-1 cells also reduced 40-50% of the effect of GATA-4 to transactivate this promoter. Interestingly, mutation of GATT at -42 caused a 70-90% increase in the transactivation of beta-B(4.8)-subunit promoter by GATA-1 or GATA-4. No significant change in the promoter activity was observed when GATT at -177 or GATC at -201 was mutated. Electrophoretic mobility shift assay confirmed the above observations that these GATA-binding proteins interacted with the GATA motif at -65 and GATT at -42, but not with GATC at -201 or GATT at -177. Serial deletion from the 5'-end of the basal promoter, from -226 to -90, markedly decreased the basal transcription, but increased the effect of GATA-1 on transactivation of the beta-B(4.8)-subunit promoter. In summary, our observations suggest that the two GATA-binding proteins transactivate the beta-B(4.8)-subunit promoter in testicular cells via complicated mechanisms. Both GATA-1 and GATA-4 factors act through the GATA motif at -65 and GATT at -42 to positively and negatively regulate the transcription from this promoter, respectively. Furthermore, GATA-1 may also interact directly or indirectly with DNA sequences at -180 to -90 to regulate the beta-B(4.8)-subunit promoter.

eng

IM

MEDLINE

0888-8809

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NLM

1820-35

pubmed-meshheading:11075815-Activins, pubmed-meshheading:11075815-Animals, pubmed-meshheading:11075815-Binding Sites, pubmed-meshheading:11075815-DNA-Binding Proteins, pubmed-meshheading:11075815-Erythroid-Specific DNA-Binding Factors, pubmed-meshheading:11075815-GATA1 Transcription Factor, pubmed-meshheading:11075815-GATA4 Transcription Factor, pubmed-meshheading:11075815-Inhibins, pubmed-meshheading:11075815-Leydig Cells, pubmed-meshheading:11075815-Male, pubmed-meshheading:11075815-Mice, pubmed-meshheading:11075815-Mutation, pubmed-meshheading:11075815-Peptides, pubmed-meshheading:11075815-Promoter Regions, Genetic, pubmed-meshheading:11075815-Rats, pubmed-meshheading:11075815-Rats, Sprague-Dawley, pubmed-meshheading:11075815-Sequence Deletion, pubmed-meshheading:11075815-Sertoli Cells, pubmed-meshheading:11075815-Testis, pubmed-meshheading:11075815-Transcription, Genetic, pubmed-meshheading:11075815-Transcription Factors, pubmed-meshheading:11075815-Transcriptional Activation

GATA-1 and GATA-4 transactivate inhibin/activin beta-B-subunit gene transcription in testicular cells.

Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't