Abstract
ran1+ (pat1+) kinase inhibits exit from the mitotic cell cycle and entry into meiosis. Inactivation of ran1+ by mei3+ is sufficient to precipitate the entire meiotic developmental program. Here, we show that the ste11+ transcription factor is a substrate for ran1+ in vitro and that this reaction is directly inhibited by mei3+. Sequence comparison reveals that ste11+ contains two domains homologous to each other and to a domain of mei3+. Mutagenesis studies reveal that the regions of homology contain substrate specificity determinants. These results identify sequences critical for phosphorylation of ste11+ by ran1+ and suggest that mei3+ employs a pseudosubstrate mechanism for its inhibitory function.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Alanine / genetics
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Arginine / genetics
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Aspartic Acid / genetics
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Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism
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DNA Mutational Analysis
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Enzyme Inhibitors / metabolism
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Fungal Proteins / metabolism*
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GTP Phosphohydrolases / genetics
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GTP Phosphohydrolases / metabolism*
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GTP-Binding Proteins / genetics
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GTP-Binding Proteins / metabolism
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Meiosis / genetics
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Mutagenesis, Site-Directed
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Nuclear Proteins / metabolism*
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Phosphorylation
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Schizosaccharomyces / enzymology*
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Schizosaccharomyces / genetics
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Schizosaccharomyces pombe Proteins*
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Sequence Homology, Amino Acid
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Serine / genetics
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Substrate Specificity
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Transcription Factors / metabolism*
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ran GTP-Binding Protein
Substances
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Enzyme Inhibitors
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Fungal Proteins
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MEI-3 protein, Neurospora crassa
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Nuclear Proteins
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Schizosaccharomyces pombe Proteins
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Transcription Factors
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ste11 protein, S pombe
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Aspartic Acid
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Serine
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Arginine
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Calcium-Calmodulin-Dependent Protein Kinases
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GTP Phosphohydrolases
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GTP-Binding Proteins
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ran GTP-Binding Protein
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Alanine