Abstract
Coordination of mitosis and cytokinesis is crucial for ensuring proper chromosome segregation and genomic stability. In Schizosaccharomyces pombe, the sid genes (cdc7, cdc11, cdc14, spg1, sid1, sid2 and sid4) define a signaling pathway that regulates septation and cytokinesis. Here we describe the characterization of a novel protein kinase, Sid1p. Sid1p localizes asymmetrically to one spindle pole body (SPB) in anaphase. Sid1p localization is maintained during medial ring constriction and septum synthesis and disappears prior to cell separation. Additionally, we found that Cdc14p is in a complex with Sid1p. Epistasis analysis places Sid1p-Cdc14p downstream of Spg1p-Cdc7p but upstream of Sid2p. Finally, we show that cyclin proteolysis during mitosis is unaffected by inactivating the sid pathway; in fact, loss of Cdc2-cyclin activity promotes Sid1p-Cdc14p association with the SPB, possibly providing a mechanism that couples cytokinesis with mitotic exit.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Blotting, Western
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Cell Cycle Proteins / metabolism
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Cell Cycle Proteins / physiology*
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Cell Division / physiology*
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Cloning, Molecular
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Flow Cytometry
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Fluorescent Antibody Technique
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Green Fluorescent Proteins
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Luminescent Proteins / metabolism
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Mitosis
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Models, Biological
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Molecular Sequence Data
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Mutagenesis
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Protein Binding
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Protein Kinases / genetics
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Protein Kinases / physiology*
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Protein Serine-Threonine Kinases / metabolism
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Protein Tyrosine Phosphatases*
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Saccharomyces cerevisiae Proteins*
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Schizosaccharomyces / physiology*
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Schizosaccharomyces pombe Proteins*
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Sequence Homology, Amino Acid
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Signal Transduction
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Time Factors
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Tubulin / metabolism
Substances
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CDC14 protein, S cerevisiae
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Cell Cycle Proteins
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Luminescent Proteins
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Saccharomyces cerevisiae Proteins
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Schizosaccharomyces pombe Proteins
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Tubulin
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Green Fluorescent Proteins
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Protein Kinases
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CDC7 protein, S cerevisiae
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Sid1 kinase
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cdc7 protein, S pombe
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Protein Serine-Threonine Kinases
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Protein Tyrosine Phosphatases