title: Genetic interactions between HOP1, RED1 and MEK1 suggest that MEK1 regulates assembly of axial element components during meiosis in the yeast Saccharomyces cerevisiae.
abstract: During meiosis, axial elements are generated by the condensation of sister chromatids along a protein core as precursors to the formation of the synaptonemal complex (SC). Functional axial elements are essential for wild-type levels of recombination and proper reductional segregation at meiosis I. Genetic and cytological data suggest that three meiosis-specific genes, HOP1, RED1 and MEK1, are involved in axial element formation in the yeast Saccharomyces cerevisiae. HOP1 and RED1 encode structural components of axial elements while MEK1 encodes a putative protein kinase. Using a partially functional allele of MEK1, new genetic interactions have been found between HOP1, RED1 and MEK1. Overexpression of HOP1 partially suppresses the spore inviability and recombination defects of mek1-974; in contrast, overexpression of RED1 exacerbates the mek1-974 spore inviability. Co-overexpression of HOP1 and RED1 in mek1-974 diploids alleviates the negative effect of overexpressing RED1 alone. Red1p/Red1p as well as Hop1p/Red1p interactions have been reconstituted in two hybrid experiments. Our results suggest a model whereby Mek1 kinase activity controls axial element assembly by regulating the affinity with which Hop1p and Red1p interact with each other.
authors.affiliation: Department of Biochemistry and Cell Biology, State University of New York at Stony Brook 11794-5215, USA. nancyhol@mcbsgi.bio.sunysb.edu
authors.forename: N M
authors.initials: NM
authors.lastname: Hollingsworth
authors.forename: L
authors.initials: L
authors.lastname: Ponte
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics*; D015870:Gene Expression; D005800:Genes, Fungal / Q000235:genetics; D048369:MAP Kinase Kinase 1; D008540:Meiosis / Q000235:genetics*; D020929:Mitogen-Activated Protein Kinase Kinases; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D011993:Recombinant Fusion Proteins; D011995:Recombination, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D013172:Spores, Fungal; D013573:Synaptonemal Complex
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C086672:HOP1 protein, S cerevisiae; C086673:RED1 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases