Plasma membrane polarization during mating in yeast cells.
The yeast mating cell provides a simple paradigm for analyzing mechanisms underlying the generation of surface polarity. Endocytic recycling and slow diffusion on the plasma membrane were shown to facilitate polarized surface distribution of Snc1p (Valdez-Taubas, J., and H.R. Pelham. 2003. Curr. Biol. 13:1636-1640). Here, we found that polarization of Fus1p, a raft-associated type I transmembrane protein involved in cell fusion, does not depend on endocytosis. Instead, Fus1p localization to the tip of the mating projection was determined by its cytosolic domain, which binds to peripheral proteins involved in mating tip polarization. Furthermore, we provide evidence that the lipid bilayer at the mating projection is more condensed than the plasma membrane enclosing the cell body, and that sphingolipids are required for this lipid organization.
Proszynski
Tomasz J
TJ
Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
Klemm
Robin
R
Bagnat
Michel
M
Gaus
Katharina
K
Simons
Kai
K
D002462:Cell Membrane / Q000378:metabolism* / Q000502:physiology; D016764:Cell Polarity; D004705:Endocytosis / Q000502:physiology; D005089:Exocytosis / Q000502:physiology; D008051:Lipid Bilayers / Q000737:chemistry; D008565:Membrane Proteins; D017434:Protein Structure, Tertiary; D050683:R-SNARE Proteins / Q000032:analysis; D012098:Reproduction / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D013107:Sphingolipids / Q000502:physiology
C490024:FUS1 protein, S cerevisiae; D008051:Lipid Bilayers; D008565:Membrane Proteins; D050683:R-SNARE Proteins; C083241:SNC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids