title: Cloning and characterization of a novel p21(Cip1/Waf1)-interacting zinc finger protein, ciz1.
abstract: p21(Cip1/Waf1) inhibits cell-cycle progression by binding to G1 cyclin/CDK complexes and proliferating cell nuclear antigen (PCNA) through its N- and C-terminal domains, respectively. Here, we report a novel p21(Cip1/Waf1)-interacting protein, Ciz1 (for Cip1 interacting zinc finger protein), which contains polyglutamine repeats and glutamine-rich region in the N-terminus as well as three zinc-finger motifs and one MH3 (matrin 3-homologous domain 3) in the C-terminal region. Ciz1 bound to the N-terminal, the CDK2-interacting part of p21(Cip1/Waf1), and the interaction was disrupted by the overexpression of CDK2. A region of about 150 amino acids containing the first zinc-finger motif in Ciz1 was the binding site for p21(Cip1/Waf1). When Ciz1 and p21(Cip1/Waf1) were individually overexpressed in U2-OS cells, they mostly localized in the nucleus. However, coexpression of Ciz1 induced cytoplasmic distribution of p21(Cip1/Waf1). These data indicate that Ciz1 is a unique nuclear protein that regulates the cellular localization of p21(Cip1/Waf1).
authors.affiliation: Institute of Life Science, Kurume University, Aikawa-machi 2432-3, Kurume, 839-0861, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Mitsui
authors.forename: A
authors.initials: A
authors.lastname: Matsumoto
authors.forename: S
authors.initials: S
authors.lastname: Ohtsuka
authors.forename: M
authors.initials: M
authors.lastname: Ohtsubo
authors.forename: A
authors.initials: A
authors.lastname: Yoshimura
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D042846:CDC2-CDC28 Kinases; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D051357:Cyclin-Dependent Kinase 2; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000737:chemistry / Q000378:metabolism; D016213:Cyclins / Q000737:chemistry* / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D016335:Zinc Fingers
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases