Recruitment of the lipid kinase Mss4 to the meiotic spindle pole promotes prospore membrane formation in Saccharomyces cerevisiae

Mol Biol Cell. 2023 Apr 1;34(4):ar33. doi: 10.1091/mbc.E22-11-0515. Epub 2023 Mar 1.

Abstract

Spore formation in the budding yeast, Saccharomyces cerevisiae, involves de novo creation of four prospore membranes, each of which surrounds a haploid nucleus resulting from meiosis. The meiotic outer plaque (MOP) is a meiosis-specific protein complex associated with each meiosis II spindle pole body (SPB). Vesicle fusion on the MOP surface creates an initial prospore membrane anchored to the SPB. Ady4 is a meiosis-specific MOP component that stabilizes the MOP-prospore membrane interaction. We show that Ady4 recruits the lipid kinase, Mss4, to the MOP. MSS4 overexpression suppresses the ady4∆ spore formation defect, suggesting that a specific lipid environment provided by Mss4 promotes maintenance of prospore membrane attachment to MOPs. The meiosis-specific Spo21 protein is an essential structural MOP component. We show that the Spo21 N terminus contains an amphipathic helix that binds to prospore membranes. A mutant in SPO21 that removes positive charges from this helix shares phenotypic similarities to ady4∆. We propose that Mss4 generates negatively charged lipids in prospore membranes that enhance binding by the positively charged N terminus of Spo21, thereby providing a mechanism by which the MOP-prospore membrane interaction is stabilized.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Membrane / metabolism
  • Lipids
  • Meiosis
  • Saccharomyces cerevisiae Proteins* / metabolism
  • Saccharomyces cerevisiae* / metabolism
  • Spindle Apparatus / metabolism
  • Spindle Poles / metabolism
  • Spores, Fungal / metabolism

Substances

  • Lipids
  • Saccharomyces cerevisiae Proteins
  • MSS4 protein, S cerevisiae