Depletion of a Cks homolog in C. elegans embryos uncovers a post-metaphase role in both meiosis and mitosis.
In eukaryotic cells, the key regulators of cell-cycle transitions are the cyclin-dependent kinases (CDKs). The best studied CDK is a component of the M-phase promoting factor (MPF), which promotes entry into and progression through meiosis and mitosis. One of the enduring mysteries of the MPF complex has been the role of Cks/Suc1, a highly conserved member of the cell-cycle machinery in eukaryotes [1,2]. Cks has been proposed to be involved in activation of MPF [3], general interactions of MPF with its mitotic substrates [4] and/or inactivation of MPF [5,6]. We identified two Cks homologs in the genome of Caenorhabditis elegans and used RNA-mediated interference (RNAi) to investigate their roles in development. Whereas cks-2(RNAi) embryos display no apparent defects, cks-1(RNAi) embryos display defects in both meiosis and mitosis. Specifically, cks-1(RNAi) embryos fail to exit M phase properly. We propose that CKS-1 has an essential role in the inactivation of MPF during early C. elegans embryogenesis.
Polinko
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Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
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D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D005656:Fungal Proteins / Q000502:physiology*; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D008677:Metaphase; D008938:Mitosis / Q000502:physiology*; D012330:RNA, Double-Stranded; D029702:Schizosaccharomyces pombe Proteins; D020687:cdc25 Phosphatases / Q000378:metabolism
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D015801:Helminth Proteins; D012330:RNA, Double-Stranded; D029702:Schizosaccharomyces pombe Proteins; C051655:Suc1 protein, S pombe; D020687:cdc25 Phosphatases