Alternative modes of organellar segregation during sporulation in Saccharomyces cerevisiae.
Formation of ascospores in the yeast Saccharomyces cerevisiae is driven by an unusual cell division in which daughter nuclei are encapsulated within de novo-formed plasma membranes, termed prospore membranes. Generation of viable spores requires that cytoplasmic organelles also be captured along with nuclei. In mitotic cells segregation of mitochondria into the bud requires a polarized actin cytoskeleton. In contrast, genes involved in actin-mediated transport are not essential for sporulation. Instead, efficient segregation of mitochondria into spores requires Ady3p, a component of a protein coat found at the leading edge of the prospore membrane. Other organelles whose mitotic segregation is promoted by actin, such as the vacuole and the cortical endoplasmic reticulum, are not actively segregated during sporulation but are regenerated within spores. These results reveal that organellar segregation into spores is achieved by mechanisms distinct from those in mitotic cells.
Suda
Yasuyuki
Y
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA.
Nakanishi
Hideki
H
Mathieson
Erin M
EM
Neiman
Aaron M
AM
D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D008540:Meiosis; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D009154:Mutation / Q000235:genetics; D015388:Organelles / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D013172:Spores, Fungal / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D014617:Vacuoles / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism
D029701:Saccharomyces cerevisiae Proteins; C468556:Ypt11 protein, S cerevisiae; D020691:rab GTP-Binding Proteins