Stimulation of later functions of the yeast meiotic protein kinase Ime2p by the IDS2 gene product.
Ime2p is a protein kinase that is expressed only during meiosis in Saccharomyces cerevisiae. Ime2p stimulates early, middle, and late meiotic gene expression and down-regulates expression of IME1, which specifies an activator of early meiotic genes that acts independently of Ime2p. We have identified a new gene, IDS2 (for IME2-dependent signaling), which has a functional relationship to Ime2p. An ids2 null mutation delays down-regulation of IME1 and expression of middle and late meiotic genes. In an ime1 null mutant that express IME2 from the GAL1 promoter (ime1 delta PGAL1-IME2 mutant), early meiotic gene expression depends only upon Ime2p. In such strains, Ids2p is dispensable for expression of the early genes HOP1 and SPO13 but is essential for expression of the middle and late genes SPS1, SPS2, and SPS100. Ids2p is also essential for the autoregulatory pathway through which Ime2p activates its own expression via the IME2 upstream activation sequences (UAS). An PGAL1-IME2 derivative that produces a truncated Ime2p (lacking its C-terminal 174 residues) permits IME2 UAS activation in the absence of Ids2p. This observation suggests that Ids2p acts upstream of Ime2p or that Ids2p and Ime2p act in independent, convergent pathways to stimulate IME2 UAS activity. Accumulation of epitope-tagged Ids2p derivatives is greatest in growing cells and declines during meiosis. We propose that Ids2p acts indirectly to modify Ime2p activity, thus permitting Ime2p to carry out later meiotic functions.
Sia
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Department of Microbiology, Columbia University, New York, New York 10032, USA.
Mitchell
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D000595:Amino Acid Sequence; D001483:Base Sequence; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D005800:Genes, Fungal / Q000235:genetics; D008040:Genetic Linkage; D047908:Intracellular Signaling Peptides and Proteins; D008540:Meiosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013172:Spores, Fungal; D013489:Suppression, Genetic; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; C095727:IDS2 protein, S cerevisiae; C080326:IME1 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases; C064979:IME2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases