title: Membrane assembly modulates the stability of the meiotic spindle-pole body.
abstract: Spore formation in Saccharomyces cerevisiae is driven by de novo assembly of new membranes termed prospore membranes. A vesicle-docking complex called the meiosis II outer plaque (MOP) forms on the cytoplasmic faces of the spindle-pole bodies at the onset of meiosis II and serves as the initiation site for membrane formation. In this study, a fluorescence-recovery assay was used to demonstrate that the dynamics of the MOP proteins change coincident with the coalescence of precursor vesicles into a membrane. Proteins within the MOP exchange freely with a soluble pool prior to membrane assembly, but after membranes are formed they remain stably within the MOP. By contrast, constitutive spindle-pole-body proteins display low exchange in both conditions. The MOP component Ady4p plays a role in maintaining the integrity of the MOP complex, but this role differs depending on whether the MOP is associated with docked vesicles or a fully formed membrane. These results suggest an architectural rearrangement of the MOP coincident with vesicle fusion.
authors.affiliation: Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Mathieson
authors.forename: Cindi
authors.initials: C
authors.lastname: Schwartz
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Neiman
mesh_terms: D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D008540:Meiosis; D008561:Membrane Fusion / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D022101:Microtubule-Organizing Center / Q000378:metabolism* / Q000648:ultrastructure; D046912:Multiprotein Complexes / Q000378:metabolism; D030781:Organisms, Genetically Modified; D055550:Protein Stability; D050765:Qa-SNARE Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion / Q000235:genetics; D013172:Spores, Fungal / Q000378:metabolism* / Q000648:ultrastructure; D019076:Transgenes / Q000235:genetics
chemical_list: C481792:Ady4 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D050765:Qa-SNARE Proteins; D011993:Recombinant Fusion Proteins; C084006:SSO1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins