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  • The EMBO Journal (2007) 26, 1843 - 1852
  • doi:10.1038/sj.emboj.7601621

Published online: 8 March 2007

Cytokinesis in yeast meiosis depends on the regulated removal of Ssp1p from the prospore membrane

Peter Maier1, Nicole Rathfelder1, Martin G Finkbeiner1,a, Christof Taxis1, Massimiliano Mazza1, Sophie Le Panse1,b, Rosine Haguenauer-Tsapis1,b and Michael Knop1

  1. EMBL, Cell Biology and Biophysics Unit, Heidelberg, Germany

Correspondence to:

Michael Knop, EMBL, Cell Biology and Biophysics Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany. Tel.: +49 6221 387631; Fax: +49 6221 387512; E-mail: knop@embl.de

aPresent address: International Agency for Research on Cancer (IARC), Unit of Gene-Environment Interaction, 150, cours Albert Thomas, 69008 Lyon, France

bPresent address: Institut Jacques Monod-CNRS, Universites Paris VI and VII, 2 Place Jussieu, 75251 PARIS Cedex 05, France

Received 6 October 2006; Accepted 26 January 2007

Intracellular budding is a developmentally regulated type of cell division common to many fungi and protists. In Saccaromyces cerevisiae, intracellular budding requires the de novo assembly of membranes, the prospore membranes (PSMs) and occurs during spore formation in meiosis. Ssp1p is a sporulation-specific protein that has previously been shown to localize to secretory vesicles and to recruit the leading edge protein coat (LEP coat) proteins to the opening of the PSM. Here, we show that Ssp1p is a multidomain protein with distinct domains important for PI(4,5)P2 binding, binding to secretory vesicles and inhibition of vesicle fusion, interaction with LEP coat components and that it is subject to sumoylation and degradation. We found non-essential roles for Ssp1p on the level of vesicle transport and an essential function of Ssp1p to regulate the opening of the PSM. Together, our results indicate that Ssp1p has a domain architecture that resembles to some extent the septin class of proteins, and that the regulated removal of Ssp1p from the PSM is the major step underlying cytokinesis in yeast sporulation.

  • Keywords:

    • cytokinesis,
    • intracellular budding,
    • septins,
    • sporulation,
    • yeast