title: DNA-binding activity of the transcription factor upstream stimulatory factor 1 (USF-1) is regulated by cyclin-dependent phosphorylation.
abstract: The ubiquitous transcription factor upstream stimulatory factor (USF) 1 is a member of the bzHLH (leucine zipper-basic-helix-loop-helix) family, which is structurally related to the Myc family of proteins. It plays a role in the regulation of many genes, including the cyclin B1 gene, which is active during the G2/M and M phases of the cell cycle and may also play a role in the regulation of cellular proliferation. We show that the affinity of recombinant USF-1 for DNA is greatly increased by treatment with active cyclin A2-p34(cdc2) or cyclin B1-p34(cdc2) complexes and that its interaction with DNA is dependent on p34(cdc2)-mediated phosphorylation. We have localized the phosphorylation site(s) to a region that lies outside the minimal DNA-binding domain but overlaps with the previously identified USF-specific region. Deletion studies of USF-1 suggest that amino acids 143-197 regulate DNA-binding activity in a phosphorylation-dependent manner.
authors.affiliation: School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Oxford Road, Manchester M13 9PT, U.K.
authors.forename: E
authors.initials: E
authors.lastname: Cheung
authors.forename: P
authors.initials: P
authors.lastname: Mayr
authors.forename: F
authors.initials: F
authors.lastname: Coda-Zabetta
authors.forename: P G
authors.initials: PG
authors.lastname: Woodman
authors.forename: D S
authors.initials: DS
authors.lastname: Boam
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002453:Cell Cycle; D016213:Cyclins / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D015342:DNA Probes / Q000235:genetics; D004268:DNA-Binding Proteins; D005260:Female; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008938:Mitosis; D009865:Oocytes / Q000378:metabolism; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051720:Upstream Stimulatory Factors; D014981:Xenopus
chemical_list: D016213:Cyclins; D015342:DNA Probes; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C497181:USF1 protein, human; D051720:Upstream Stimulatory Factors; D004247:DNA; D016203:CDC2 Protein Kinase