Identification of a candidate c-mos repressor that restricts transcription of germ cell-specific genes.

Abstract

The c-mos proto-oncogene is specifically expressed in female and male germ cells. Previous studies identified a negative regulatory element (NRE) upstream of the c-mos promoter that suppresses c-mos transcription in transfected NIH 3T3 cells. In this study, we used gel shift assays to detect proteins in nuclear extracts of NIH 3T3 cells that bind to the c-mos NRE in a sequence-specific manner. One protein was found to bind to a region of the NRE which was shown by site-directed mutagenesis to be required for suppression of c-mos transcription. This factor was present in nuclear extracts of several somatic cell lines and tissues but not in male germ cells in which c-mos is transcribed, suggesting that it is a somatic cell repressor of c-mos transcription. The binding site of the candidate repressor within the c-mos NRE consists of sequences related to putative NREs identified in two other male germ cell-specific genes (encoding protamine 2 and phosphoglycerate kinase 2). The c-mos repressor bound and could be UV cross-linked to these protamine 2 and phosphoglycerate kinase 2 gene sequences as a protein with an apparent molecular mass of approximately 30 kDa. The repressor binding site is also conserved in two other germ cell-specific genes (encoding testis-specific cytochrome c and heat shock-like protein 70), suggesting that the c-mos repressor may be generally involved in suppressing transcription of germ cell-specific genes in somatic cells.

• Authors: W Xu, G M Cooper
• Journal: Molecular and cellular biology (Mol Cell Biol) Vol. 15 Issue 10 Pg. 5369-75 (Oct 1995) ISSN: 0270-7306 [Print] United States
• PMID: 7565687 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Cell Extracts
• Cytochrome c Group
• HSP70 Heat-Shock Proteins
• Protamines
• Repressor Proteins
• protamine 2
• DNA
• Phosphotransferases (Alcohol Group Acceptor)
• glycerate kinase

Topics

• 3T3 Cells
• Animals
• Base Sequence
• Cell Extracts
• Cell Nucleus (metabolism)
• Consensus Sequence (genetics)
• Cytochrome c Group (genetics)
• DNA (metabolism)
• Female
• Genes, mos (genetics)
• HSP70 Heat-Shock Proteins (genetics)
• Male
• Mice
• Molecular Sequence Data
• Molecular Weight
• Phosphotransferases (Alcohol Group Acceptor) (genetics)
• Protamines (genetics)
• Regulatory Sequences, Nucleic Acid (genetics)
• Repressor Proteins (chemistry, metabolism)
• Spermatozoa (metabolism)
• Transcription, Genetic (genetics)