title: Identification of non-Ser/Thr-Pro consensus motifs for Cdk1 and their roles in mitotic regulation of C2H2 zinc finger proteins and Ect2.
abstract: The cyclin B-dependent protein kinase Cdk1 is a master regulator of mitosis and phosphorylates numerous proteins on the minimal consensus motif Ser/Thr-Pro (S/T-P). At least in several proteins, however, not well-defined motifs lacking a Pro in the +1 position, referred herein to as non-S/T-P motifs, have been shown to be phosphorylated by Cdk1. Here we show that non-S/T-P motifs in fact form consensus sequences for Cdk1 and probably play roles in mitotic regulation of physiologically important proteins. First, we show, by in vitro kinase assays, that previously identified non-S/T-P motifs all harbour one or more C-terminal Arg/Lys residues essential for their phosphorylation by Cdk1. Second, using Arg/Lys-scanning oriented peptide libraries, we demonstrate that Cdk1 phosphorylates a minimal sequence S/T-X-X-R/K and more favorable sequences (P)-X-S/T-X-[R/K](2-5) as its non-S/T-P consensus motifs. Third, on the basis of these results, we find that highly conserved linkers (typically, T-G-E-K-P) of C2H2 zinc finger proteins and a nuclear localization signal-containing sequence (matching P-X-S-X-[R/K]5) of the cytokinesis regulator Ect2 are inhibitorily phosphorylated by Cdk1, well accounting for the known mitotic regulation and function of the respective proteins. We suggest that non-S/T-P Cdk1 consensus motifs identified here may function to regulate many other proteins during mitosis.
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Sako
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Akiyama
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Michitaka
authors.initials: M
authors.lastname: Isoda
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Senoo
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Nobushige
authors.initials: N
authors.lastname: Nakajo
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sagata
mesh_terms: D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis; D016335:Zinc Fingers
chemical_list: D011518:Proto-Oncogene Proteins; D029867:Xenopus Proteins; D016203:CDC2 Protein Kinase