Human Cdk2 is a functional homolog of budding yeast Ime2, the meiosis-specific Cdk-like kinase.
Progression through the cell cycle depends on sequential activation of Cyclin-Dependent Kinase(s). In this report we use budding-yeast meiosis as a tool to elucidate the specific functions of mammalian Cdks. Yeast meiosis is regulated by both Cdc28 (yCdk1) and Ime2 (a meiosis-specific Cdk-like kinase). We show that human Cdk2 is a functional homolog for most of Ime2 functions. It promotes efficient and timely entry into premeiotic DNA replication and the first nuclear division, as well as the regulated transcription of IME1 and the early meiosis-specific genes. We show that this effect is specific, and that neither mice Cdk1, nor mice Cdk4 can suppress ime2. We show that Cdk1 is a functional homolog of Cdc28 that also suppresses one of its meiotic functions, namely inhibiting the transcription of IME1. Cdk2, on the other hand, show dominant negative effects on entry into the cell cycle, most probably by inhibiting the function of Cdc28. Finally, we show that in the meiotic pathway Cdk4 functions as a transcriptional activator.
Szwarcwort-Cohen
Moran
M
Department of Biology, Technion, Haifa, Israel.
Kasulin-Boneh
Zohar
Z
Sagee
Shira
S
Kassir
Yona
Y
D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D017489:CDC28 Protein Kinase, S cerevisiae / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D051357:Cyclin-Dependent Kinase 2 / Q000235:genetics / Q000378:metabolism*; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D009584:Nitrogen / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C064979:IME2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D017489:CDC28 Protein Kinase, S cerevisiae; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D009584:Nitrogen