Title: | Cdc42p and Fus2p act together late in yeast cell fusion |
Author(s): | Ydenberg CA; Stein RA; Rose MD; |
Address: | "Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA" |
ISSN/ISBN: | 1939-4586 (Electronic) 1059-1524 (Print) 1059-1524 (Linking) |
Abstract: | "Cell fusion is the key event of fertilization that gives rise to the diploid zygote and is a nearly universal aspect of eukaryotic biology. In the yeast Saccharomyces cerevisiae, several mutants have been identified that are defective for cell fusion, and yet the molecular mechanism of this process remains obscure. One obstacle has been that genetic screens have mainly focused on mating-specific factors, whereas the process likely involves housekeeping proteins as well. Here we implicate Cdc42p, an essential protein with roles in multiple aspects of morphogenesis, as a core component of the yeast cell fusion pathway. We identify a point mutant in the Rho-insert domain of CDC42, called cdc42-138, which is specifically defective in cell fusion. The cell fusion defect is not a secondary consequence of ineffective signaling or polarization. Genetic and morphological data show that Cdc42p acts at a late stage in cell fusion in concert with a key cell fusion regulator, Fus2p, which contains a Dbl-homology domain. We find that Fus2p binds specifically with activated Cdc42p, and binding is blocked by the cdc42-138 mutation. Thus, in addition to signaling and morphogenetic roles in mating, Cdc42p plays a role late in cell fusion via activation of Fus2p" |
Keywords: | "Cell Polarity Cytoskeletal Proteins/chemistry/genetics/*metabolism Genes, Fungal Guanosine Triphosphate/metabolism Mating Factor Membrane Proteins/chemistry/genetics/*metabolism Microscopy, Electron, Transmission Models, Molecular Peptides/metabolism Pher;" |
Notes: | "MedlineYdenberg, Casey A Stein, Richard A Rose, Mark D eng R01 GM037739/GM/NIGMS NIH HHS/ GM37739/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural 2012/02/11 Mol Biol Cell. 2012 Apr; 23(7):1208-18. doi: 10.1091/mbc.E11-08-0723. Epub 2012 Feb 9" |