Protein S-palmitoylation regulates different stages of meiosis in Schizosaccharomyces pombe

Posttranslational protein S-palmitoylation regulates the localization and function of its target proteins involved in diverse cellular processes including meiosis. In this study, we demonstrate that S-palmitoylation mediated by Erf2-Erf4 and Akr1 palmitoylacyltransferases is required at multiple meiotic stages in the fission yeast Schizosaccharomyces pombe. We find that S-palmitoylation by Erf2-Erf4 is required for Ras1 localization at the cell periphery to enrich at the cell conjugation site for mating pheromone response. In the absence of Erf2 or Erf4, mutant cells are sterile. A role of Akr1 S-palmitoylating the nuclear fusion protein Tht1 to function in karyogamy is identified. We demonstrate that S-palmitoylation stabilizes and localizes Tht1 to ER, interacting with Sey1 ER fusion GTPase for proper meiotic nuclear fusion. In akr1, tht1, or sey1 mutant, meiotic cells, haploid nuclei are unfused with subsequent chromosome segregation defects. Erf2-Erf4 has an additional substrate of the spore coat protein Isp3. In the absence of Erf2, Isp3 is mislocalized from the spore coat. Together, these results highlight the versatility of the cellular processes in which protein S-palmitoylation participates.

Automated summary

In this study, the requirement of S-palmitoylation mediated by Erf2-Erf4 and Akr1 palmitoylacyltransferases at multiple meiotic stages in Schizosaccharomyces pombe was demonstrated. S-palmitoylation by Erf2-Erf4 was found to be necessary for the localization of Ras1 at the cell periphery for mating pheromone response, while Akr1 mediated S-palmitoylation of Tht1 was identified to be crucial for meiotic nuclear fusion. The study also revealed the additional substrate of Erf2-Erf4, the spore coat protein Isp3, which was mislocalized in the absence of Erf2.