title: Alternative forms of Max as enhancers or suppressors of Myc-ras cotransformation.
abstract: Max is a basic-helix-loop-helix-leucine zipper protein capable of forming sequence-specific DNA binding complexes with Myc proteins. An alternatively spliced messenger RNA has been identified that encodes a form of Max truncated at the COOH-terminus. This delta Max protein retained the ability to bind to the CACGTG motif in a complex with c-Myc but lacks the nuclear localization signal and the putative regulatory domain of Max. When tested in a myc-ras cotransformation assay in rat embryo fibroblasts, Max suppressed, whereas delta Max enhanced, transformation. Thus, the max gene may encode both a negative and a positive regulator of c-Myc function.
authors.affiliation: Department of Virology, University of Helsinki, Finland.
authors.forename: T P
authors.initials: TP
authors.lastname: Mäkelä
authors.forename: P J
authors.initials: PJ
authors.lastname: Koskinen
authors.forename: I
authors.initials: I
authors.lastname: Västrik
authors.forename: K
authors.initials: K
authors.lastname: Alitalo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D005347:Fibroblasts; D016259:Genes, myc; D011905:Genes, ras; D006801:Humans; D007163:Immunosorbent Techniques; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013329:Structure-Activity Relationship; D014157:Transcription Factors; D014162:Transfection
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C499330:MAX protein, human; C499329:Max protein, rat; C067850:Myc associated factor X; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D014157:Transcription Factors; D004247:DNA