Molecular mimicry in development: identification of ste11+ as a substrate and mei3+ as a pseudosubstrate inhibitor of ran1+ kinase.
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.
Li
P
P
Department of Microbiology and Immunology, Morse Institute for Molecular Biology and Genetics, State University of New York Health Science Center at Brooklyn 11023, USA.
McLeod
M
M
D000409:Alanine / Q000235:genetics; D001120:Arginine / Q000235:genetics; D001224:Aspartic Acid / Q000235:genetics; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004252:DNA Mutational Analysis; D004791:Enzyme Inhibitors / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D008540:Meiosis / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000235:genetics; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000235:genetics; D013379:Substrate Specificity; D014157:Transcription Factors / Q000378:metabolism*; D020931:ran GTP-Binding Protein
D004791:Enzyme Inhibitors; D005656:Fungal Proteins; C083569:MEI-3 protein, Neurospora crassa; D009687:Nuclear Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C071596:ste11 protein, S pombe; D001224:Aspartic Acid; D012694:Serine; D001120:Arginine; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020931:ran GTP-Binding Protein; D000409:Alanine