title: Synergism in ternary complex formation between the dimeric glycoprotein p67SRF, polypeptide p62TCF and the c-fos serum response element.
abstract: Transcriptional regulation of the c-fos proto-oncogene requires the serum response element (SRE) which is complexed by a multi-protein assembly observed both in vitro and in vivo. Two protein factors, p67SRF and p62TCF (previously called p62), are required to interact with the SRE for efficient induction of c-fos by serum. By quantitative band shift electrophoresis we measure at least a 50-fold increase in SRE affinity for p67SRF/p62TCF over p67SRF alone. Stoichiometrically we determine that the ternary complex with p62TCF involves p67SRF in dimeric form. We demonstrate that p67SRF is a glycosylated nuclear transcription factor carrying terminal N-acetylglucosamine (GlcNAc) as a post-translational modification. A proteolytic limit digestion product, approximately 13 kd in size, was generated from the p67SRF-SRE complex. This p67SRF-core domain binds SRE, can dimerize with p67SRF and is still able to form a ternary complex with p62TCF. Therefore, three functional activities can be ascribed to this small p67SRF-core domain: specific DNA binding, dimerization and interaction with p62TCF. We demonstrate that these functions map within the p67SRF core fragment containing the region between amino acids 93 and 222.
authors.affiliation: Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, FRG.
authors.forename: H
authors.initials: H
authors.lastname: Schröter
authors.forename: C G
authors.initials: CG
authors.lastname: Mueller
authors.forename: K
authors.initials: K
authors.lastname: Meese
authors.forename: A
authors.initials: A
authors.lastname: Nordheim
mesh_terms: D001483:Base Sequence; D002738:Chloroquine / Q000494:pharmacology; D005786:Gene Expression Regulation; D006031:Glycosylation; D006367:HeLa Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology*; D015345:Oligonucleotide Probes; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016760:Proto-Oncogene Proteins c-fos; D011519:Proto-Oncogenes; D026362:Serum Response Factor; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C000715470:MAS1 protein, human; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D026362:Serum Response Factor; D014157:Transcription Factors; D002738:Chloroquine; D011505:Protein-Tyrosine Kinases