The role of transcription enhancer factor-1 (TEF-1) related proteins in the formation of M-CAT binding complexes in muscle and non-muscle tissues.
M-CAT sites are required for the activity of many promoters in cardiac and skeletal muscle. M-CAT binding activity is muscle-enriched, but is found in many tissues and is immunologically related to the HeLa transcription enhancer factor-1 (TEF-1). TEF-1-related cDNAs (RTEF-1) have been cloned from chick heart. RTEF-1 mRNA is muscle-enriched, consistent with a role for RTEF-1 in the regulation of muscle-specific gene expression. Here, we have examined the tissue distribution of TEF-1-related proteins and of M-CAT binding activity by Western analysis and mobility shift polyacrylamide gel electrophoresis. TEF-1-related proteins of 57, 54 and 52 kDa were found in most tissues with the highest levels in muscle tissues. All of these TEF-1-related proteins bound M-CAT DNA and the 57- and 54-kDa TEF-1-related polypeptides were phosphorylated. Proteolytic digestion mapping showed that the 54-kDa TEF-1-related polypeptide is encoded by a different gene than the 52- and 57-kDa TEF-1-related polypeptides. A comparison of the migration and proteolytic digestion of the 54-kDa TEF-1-related polypeptide with proteins encoded by the cloned RTEF-1 cDNAs showed that the 54-kDa TEF-1-related polypeptide is encoded by RTEF-1A. High resolution mobility shift polyacrylamide gel electrophoresis showed multiple M-CAT binding activities in tissues. All of these activities contained TEF-1-related proteins. One protein-M-CAT DNA complex was muscle-enriched and was up-regulated upon differentiation of a skeletal muscle cell line. This complex contained the 54-kDa TEF-1-related polypeptide. Therefore, RTEF1-A protein is a component of a muscle-enriched transcription complex that forms on M-CAT sites and may play a key role in the regulation of transcription in muscle.
Farrance
I K
IK
Department of Anatomy and Cardiovascular Research Institute, University of California, San Francisco, 94143, USA.
Ordahl
C P
CP
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D005796:Genes; D007158:Immunologic Techniques; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family; D009132:Muscles / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D000091262:TEA Domain Transcription Factors; D014018:Tissue Distribution; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D000091262:TEA Domain Transcription Factors; C057182:TEAD1 protein, human; D014157:Transcription Factors