Find in Library

During sporulation in the budding yeast <i>Saccharomyces cerevisiae</i>, proper development of the prospore membrane is necessary for the formation of viable spores. The prospore membrane will eventually become the plasma membrane of the newly formed haploid spore and also serves as the template for the deposition of the spore wall. The prospore membrane is generated de novo during meiosis II and the growing edge of the prospore membrane is associated with the Leading Edge Protein (LEP) complex. We find that the Smk1 MAP kinase, along with its activator Ssp2, transiently localizes with the LEP during late meiosis II. <i>SSP2</i> is required for the leading edge localization of Smk1; this localization is independent of the activation state of Smk1. Like other LEP components, the localization of Smk1 at the leading edge also depends on Ady3. Although prospore membrane development begins normally in <i>smk1</i> and <i>ssp2</i> mutants, late prospore membrane formation is disrupted, with the formation of ectopic membrane compartments. Thus, MAP kinase signaling plays an important role in the formation of the prospore membrane.