title: IME1 gene encodes a transcription factor which is required to induce meiosis in Saccharomyces cerevisiae.
abstract: Previous studies have shown that the IME1 gene is required for sporulation and the expression of meiosis specific genes in Saccharomyces cerevisiae. However, sequence analysis has not revealed the precise functional role of the Ime1 protein. By engineering constructs which express various portions of the Ime1p fused to either the DNA binding or transcriptional activation domains of GAL4, we have conclusively demonstrated that IME1 is a transcription factor, apparently required for sporulation to activate the transcription of meiosis specific genes. The full Ime1p, when fused to the GAL4 DNA binding domain, can both activate GAL1-lacZ expression, and complement ime1-0 (a null allele) for the ability to sporulate, and transcriptionally activate IME2, a meiosis specific gene. As successively larger portions of the encoded Ime1p N-terminus are deleted from the GAL4(bd)-IME1 construct, the encoded fusion proteins retain the ability to complement an ime1 null allele, despite a decreasing ability to activate GAL1-lacZ transcription. However, a fusion construct which retains only the last 45 C-terminal amino acids of IME1 provides neither transcriptional activation of GAL1-lacZ nor complementation of ime1-0. Fusion of a GAL4 activation domain to this portion of IME1, results in a construct with a restored ability to complement an ime1-0 allele. This restored ability is dependent upon galactose induction. We conclude, therefore, that IME1 functions in meiosis as a transcriptional activator.
authors.affiliation: Department of Biology, Technion-Israel Institute of Technology, Haifa.
authors.forename: S
authors.initials: S
authors.lastname: Mandel
authors.forename: K
authors.initials: K
authors.lastname: Robzyk
authors.forename: Y
authors.initials: Y
authors.lastname: Kassir
mesh_terms: D001483:Base Sequence; D018797:Cell Cycle Proteins; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D008540:Meiosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D009838:Oligodeoxyribonucleotides; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D013172:Spores, Fungal / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D005656:Fungal Proteins; C080326:IME1 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases; C064979:IME2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D001616:beta-Galactosidase