SPO21 is required for meiosis-specific modification of the spindle pole body in yeast.
During meiosis II in the yeast Saccharomyces cerevisiae, the cytoplasmic face of the spindle pole body changes from a site of microtubule initiation to a site of de novo membrane formation. These membranes are required to package the haploid meiotic products into spores. This functional change in the spindle pole body involves the expansion and modification of its cytoplasmic face, termed the outer plaque. We report here that SPO21 is required for this modification. The Spo21 protein localizes to the spindle pole in meiotic cells. In the absence of SPO21 the structure of the outer plaque is abnormal, and prospore membranes do not form. Further, decreased dosage of SPO21 leaves only two of the four spindle pole bodies competent to generate membranes. Mutation of CNM67, encoding a known component of the mitotic outer plaque, also results in a meiotic outer plaque defect but does not block membrane formation, suggesting that Spo21p may play a direct role in initiating membrane formation.
Bajgier
B K
BK
Department of Biochemistry and Cell Biology and Institute for Cell and Developmental Biology, State University of New York at Stony Brook, 11794-5215, USA.
Malzone
M
M
Nickas
M
M
Neiman
A M
AM
D000483:Alleles; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019084:Fluorescent Antibody Technique, Indirect; D005656:Fungal Proteins / Q000378:metabolism*; D005838:Genotype; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008540:Meiosis; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
C432934:Cnm67 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C432933:Spo21 protein, S cerevisiae; D049452:Green Fluorescent Proteins