Identification and characterization of individual cyclin-dependent kinase complexes from Saccharomyces cerevisiae.
In S. cerevisiae, regulation of cell cycle progression is known to be carried out by a single cyclin-dependent kinase homologue, Cdc28p, acting at different stages of the cell cycle in association with various cyclins and other regulatory subunits. However, a still unsolved problem is the identification of the physiologically relevant substrates of the different Cdc28p kinase complexes which participate in this regulation. Purification and characterization of the subunit composition and enzymological properties of these Cdc28p complexes would therefore contribute substantially to our understanding of the molecular mechanisms controlling the cell cycle. We have used a combination of ammonium sulphate fractionation, nickel nitrilotriacetate affinity purification, ATP Sepharose affinity chromatography and Resource Q ion exchange chromatography to purify two different Cdc28p kinase complexes. Using specific clb deletion mutants and plasmid or genomic HA epitope-tagged CLBs, we show that one of these complexes is composed almost exclusively (93% or greater) of Clb2p-Cdc28p, whereas the other is mainly (75% or greater) Clb3p-Cdc28p. These procedures provide the basis for the analysis of regulatory, enzymatic and functional properties of individual Cdc28p kinase complexes.
Shellman
Y G
YG
Department of Biochemistry and Molecular Genetics, University of Colorado Health Science Center, Denver 80262, USA.
Svee
E
E
Sclafani
R A
RA
Langan
T A
TA
D017489:CDC28 Protein Kinase, S cerevisiae / Q000302:isolation & purification* / Q000378:metabolism*; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D018844:Cyclin-Dependent Kinases / Q000145:classification* / Q000302:isolation & purification; D016213:Cyclins / Q000378:metabolism; D015151:Immunoblotting; D011233:Precipitin Tests; D011494:Protein Kinases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D013379:Substrate Specificity
D016213:Cyclins; D011494:Protein Kinases; C102333:histone H1 kinase; D017489:CDC28 Protein Kinase, S cerevisiae; D018844:Cyclin-Dependent Kinases