Novel complexes of cyclin-dependent kinases and a cyclin-like protein from Arabidopsis thaliana with a function unrelated to cell division

• Published in: Cellular and molecular life sciences : CMLS Vol. 60; no. 2; pp. 401 - 412
• Main Authors: Barrôco, R. M, De Veylder, L, Magyar, Z, Engler, G, Inzé, D, Mironov, V
• Format: Journal Article
• Language: English
• Published: Switzerland Birkhäuser Verlag 01.02.2003; Springer Nature B.V
• Subjects: Amino Acid Motifs; Amino Acid Sequence; Arabidopsis; Arabidopsis - chemistry; Arabidopsis - metabolism; Arabidopsis thaliana; Cell cycle; Cell differentiation; Cell Division; cyclin-dependent kinase; Cyclin-Dependent Kinases - chemistry; Cyclin-Dependent Kinases - metabolism; cyclins; Cyclins - chemistry; Cyclins - metabolism; Elongated structure; Evolution, Molecular; flowers; Gene Expression Regulation, Plant; Gene regulation; Homology; Immunoprecipitation; Kinases; mammals; Molecular Sequence Data; Plant biology; precipitin tests; Protein Structure, Tertiary; Proteins; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Homology, Amino Acid; tissues; Transcription elongation factor b; two hybrid system techniques; Yeasts
• ISSN: 1420-682X; 1420-9071
• DOI: 10.1007/s000180300033

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.