Candida Albicans Als1p: An Adhesin That Is a Downstream Effector of the Efg1 Filamentation Pathway
Resource
MOLECULAR MICROBIOLOGY v.44 n.1 pp.61-72
Journal
MOLECULAR MICROBIOLOGY
Journal Volume
v.44
Journal Issue
n.1
Pages
61-72
Date Issued
2002
Date
2002
Author(s)
CHEN, YEE-CHUN
Abstract
Filamentation and adherence to host cells are critical virulence factors of Candida albicans . Multiple filamentation regulatory pathways have been discovered in C. albicans using Saccharomyces cerevisiae as a model. In S . cerevisiae , these pathways converge on Flo11p, which functions as a downstream effector of filamentation and also mediates cell-cell adherence (flocculation). In C. albicans , such effector(s) have not yet been identified. Here, we demonstrate that the cell surface protein Als1p is an effector of filamentation in C. albicans . We show that Als1 p expression is controlled by the transcription factor Efg1 p, which is known to be a key regulator of filamentation in C. albicans . Further, disruption of ALS 1 inhibited filamentation, and autonomous expression of Als1p restored filamentation in an efg1 homozygous null mutant. Thus, Als1p functions as a downstream effector of the EFG1 filamentation pathway. In addition, we found that Als1p mediates both flocculation and adherence of C. albicans to endothelial cells in vitro . As a cell surface glycoprotein that mediates filamentation and adherence, Als1p has both structural and functional similarity to S. cerevisiae Flo11p . Consistent with our in vitro results, Als1p was required for both normal filamentation and virulence in the mouse model of haematogenously disseminated candidiasis.
Subjects
CELL-CELL ADHESION
HYPHAL FORMATION
GENE
VIRULENCE
GROWTH
YEAST
Type
journal article