title: An immediate early human gene encodes an Id-like helix-loop-helix protein and is regulated by protein kinase C activation in diverse cell types.
abstract: Transcription factors characterized by the presence of a helix-loop-helix (HLH) domain play a central role in the regulation of cell growth/differentiation and tumorigenesis. We report here the cDNA sequence of a human early-response gene, designated HLH 1R21, encoding a 15-kDa HLH protein that lacks a basic, DNA-binding domain and which by a number of criteria appears to be the human homologue of mouse HLH 462. Like its murine counterpart, HLH 1R21 protein functions as an Id (inhibitor of DNA binding) transcription factor by inhibiting the binding of E2A-containing protein complexes to muscle creatine kinase E-box enhancer oligonucleotide in vitro. However HLH 1R21 does not inhibit the binding of HLH Max protein to a Max-binding oligonucleotide in vitro, indicating that it has limited promiscuity in its ability to antagonize the function of other HLH transcription factors. In addition, HLH 1R21 mRNA transcripts are regulated by phorbol ester treatment of a diverse range of human cell lines and, when overexpressed in mouse NIH3T3 cells, HLH 1R21 induces a morphologically transformed phenotype.
authors.affiliation: CRC Department of Gene Regulation, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.
authors.forename: R W
authors.initials: RW
authors.lastname: Deed
authors.forename: S M
authors.initials: SM
authors.lastname: Bianchi
authors.forename: G T
authors.initials: GT
authors.lastname: Atherton
authors.forename: D
authors.initials: D
authors.lastname: Johnston
authors.forename: M
authors.initials: M
authors.lastname: Santibanez-Koref
authors.forename: J J
authors.initials: JJ
authors.lastname: Murphy
authors.forename: J D
authors.initials: JD
authors.lastname: Norton
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D004789:Enzyme Activation; D005786:Gene Expression Regulation / Q000187:drug effects; D015894:Genome, Human; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000235:genetics*; D051796:Inhibitor of Differentiation Proteins; D051379:Mice; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000502:physiology*; D011506:Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D007130:Immunoglobulin Idiotypes; D051796:Inhibitor of Differentiation Proteins; D011506:Proteins; D014157:Transcription Factors; C067679:Idb3 protein, mouse; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate