Membrane curvature directs the localization of Cdc42p to novel foci required for cell-cell fusion.

TitleMembrane curvature directs the localization of Cdc42p to novel foci required for cell-cell fusion.
Publication TypeJournal Article
Year of Publication2017
AuthorsSmith, JA, Hall, AE, Rose, MD
JournalJ Cell Biol
Date Published2017 Dec 04
Keywordscdc42 GTP-Binding Protein, Saccharomyces cerevisiae, Cell Fusion, Cell Membrane, Cell Wall, Cytoskeletal Proteins, Gene Expression Regulation, Fungal, Genes, Reporter, Green Fluorescent Proteins, Hydrolysis, Luminescent Proteins, Mating Factor, Membrane Proteins, Mutation, Phosphorylation, Protein Binding, Protein Multimerization, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Signal Transduction

<p>Cell fusion is ubiquitous in eukaryotic fertilization and development. The highly conserved Rho-GTPase Cdc42p promotes yeast fusion through interaction with Fus2p, a pheromone-induced amphiphysin-like protein. We show that in prezygotes, Cdc42p forms a novel Fus2p-dependent focus at the center of the zone of cell fusion (ZCF) and remains associated with remnant cell walls after initial fusion. At the ZCF and during fusion, Cdc42p and Fus2p colocalized. In contrast, in shmoos, both proteins were near the cortex but spatially separate. Cdc42p focus formation depends on ZCF membrane curvature: mutant analysis showed that Cdc42p localization is negatively affected by shmoo-like positive ZCF curvature, consistent with the flattening of the ZCF during fusion. BAR-domain proteins such as the fusion proteins Fus2p and Rvs161p are known to recognize membrane curvature. We find that mutations that disrupt binding of the Fus2p/Rvs161p heterodimer to membranes affect Cdc42p ZCF localization. We propose that Fus2p localizes Cdc42p to the flat ZCF to promote cell wall degradation.</p>

Alternate JournalJ Cell Biol
PubMed ID29066609
PubMed Central IDPMC5716282
Grant ListR01 GM037739 / GM / NIGMS NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States