Ady4p and Spo74p are components of the meiotic spindle pole body that promote growth of the prospore membrane in Saccharomyces cerevisiae.
Spore formation in Saccharomyces cerevisiae occurs via the de novo synthesis of the prospore membrane during the second meiotic division. Prospore membrane formation is triggered by assembly of a membrane-organizing center, the meiotic outer plaque (MOP), on the cytoplasmic face of the spindle pole body (SPB) during meiosis. We report here the identification of two new components of the MOP, Ady4p and Spo74p. Ady4p and Spo74p interact with known proteins of the MOP and are localized to the outer plaque of the SPB during meiosis II. MOP assembly and prospore membrane formation are abolished in spo74Delta/spo74Delta cells and occur aberrantly in ady4Delta/ady4Delta cells. Spo74p and the MOP component Mpc70p are mutually dependent for recruitment to SPBs during meiosis. In contrast, both Ady4p and Spo74p are present at SPBs, albeit at reduced levels, in cells that lack the MOP component Mpc54p. Our findings suggest a model for the assembled MOP in which Mpc54p, Mpc70p, and Spo74p make up a core structural unit of the scaffold that initiates synthesis of the prospore membrane, and Ady4p is an auxiliary component that stabilizes the plaque.
Nickas
Mark E
ME
Department of Biochemistry and Cell Biology and Institute for Cell and Developmental Biology, State University of New York at Stony Brook, Stony Brook, New York 11794-5215, USA.
Schwartz
Cindi
C
Neiman
Aaron M
AM
D002503:Centromere / Q000235:genetics; D003598:Cytoskeletal Proteins; D005800:Genes, Fungal; D005819:Genetic Markers; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008540:Meiosis / Q000502:physiology*; D008565:Membrane Proteins; D008954:Models, Biological; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D008941:Spindle Apparatus / Q000737:chemistry / Q000502:physiology*; D013172:Spores, Fungal / Q000166:cytology / Q000648:ultrastructure
C481792:Ady4 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D005819:Genetic Markers; D008164:Luminescent Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C481793:Spo74 protein, S cerevisiae; D049452:Green Fluorescent Proteins