The Sur7 protein resides in punctate membrane subdomains and mediates spatial regulation of cell wall synthesis in Candida albicans.
The eukaryotic plasma membrane is organized into distinct domains that contribute to its function. One new type of plasma membrane domain was identified by studies on the Sur7 protein, which was discovered in the yeast S. cerevisiae to localize into stable punctate patches known as MCC or eisosomes. Sur7 shares similarities with Claudin proteins that form tight junction domains in animal cells, suggesting common roles for these tetraspanning membrane proteins. Recent analysis of C. albicans revealed broad new roles for Sur7; a sur7Delta mutant mislocalized septins and actin and was defective in morphogenesis. Strikingly, cell wall synthesis was very abnormal, including long projections of chitin-rich cell wall into the cytoplasm. Some phenotypes of the sur7Delta mutant are similar to the effects of inhibiting cell wall beta-glucan synthesis. This suggests that the abnormal cell wall structures are related to the increased chitin synthesis commonly seen under cell wall stress conditions, which could be mediated in part by the altered septin localization. Altogether, these results identify new roles for Sur7 and MCC/eisosomes in plasma membrane organization and coordination of the different aspects of cell wall synthesis.
Alvarez
Francisco J
FJ
Department of Molecular Genetics and Microbiology; Stony Brook University; Stony Brook, NY USA.
Douglas
Lois M
LM
Konopka
James B
JB
Prog Lipid Res. 2006 Nov;45(6):447-65
16730802
J Biol Chem. 2000 Jun 9;275(23):17221-4
10770957
J Cell Sci. 2004 Dec 1;117(Pt 25):6031-41
15536122
Nat Rev Mol Cell Biol. 2005 Oct;6(10):801-11
16314869
Nature. 2006 Feb 23;439(7079):998-1003
16496001
EMBO J. 2007 Dec 12;26(24):4946-55
18034155
Mol Biol Cell. 2003 Nov;14(11):4427-36
14551254
Yeast. 1997 Jun 30;13(8):747-61
9219339
Trends Cell Biol. 2006 Apr;16(4):181-8
16537104
EMBO J. 2007 Jan 10;26(1):1-8
17170709
Mol Cell Biol. 2002 Feb;22(3):927-34
11784867
J Biol Chem. 2008 Apr 18;283(16):10433-44
18296441
Mol Biol Cell. 2008 Dec;19(12):5214-25
18799621
Nat Cell Biol. 2003 Jul;5(7):626-32
12819789
J Lipid Res. 2008 May;49(5):909-21
18296751