title: Novel complexes of cyclin-dependent kinases and a cyclin-like protein from Arabidopsis thaliana with a function unrelated to cell division.
abstract: Although the majority of cyclin-dependent kinases (CDKs) play a key role in cell cycle progression, recent evidence has shown that CDKs are also implicated in transcription regulation. Here, we describe two Arabidopsis CDKs designated Arath;CDKC;1 and Arath; CDKC;2. These CDKs share a PITAIRE signature in the cyclin-binding domain and the structural characteristics of mammalian CDK9. Yeast two-hybrid screens and immunoprecipitation assays identified CDKC-interacting proteins with homology to the animal cyclin T/cyclin K group. We suggest that these Arabidopsis CDKCs may be part of a kinase complex similar to the animal positive transcription elongation factor b, whose activity is essential for transcription control. Expression studies showed that Arath; CDKC transcripts are mainly confined to epidermal tissues and are most abundant in flower tissues. No expression was detected in actively dividing Arabidopsis tissues, suggesting a role for the CDKC proteins in differentiated cells.
authors.affiliation: Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium.
authors.forename: R M
authors.initials: RM
authors.lastname: Barrôco
authors.forename: L
authors.initials: L
authors.lastname: De Veylder
authors.forename: Z
authors.initials: Z
authors.lastname: Magyar
authors.forename: G
authors.initials: G
authors.lastname: Engler
authors.forename: D
authors.initials: D
authors.lastname: Inzé
authors.forename: V
authors.initials: V
authors.lastname: Mironov
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry / Q000378:metabolism*; D002455:Cell Division; D018844:Cyclin-Dependent Kinases / Q000737:chemistry* / Q000378:metabolism*; D016213:Cyclins / Q000737:chemistry* / Q000378:metabolism*; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D016213:Cyclins; D012333:RNA, Messenger; D018844:Cyclin-Dependent Kinases