R. Alonso-monge et al., Role of the mitogen-activated protein kinase hog1p in morphogenesis and virulence of Candida albicans, J BACT, 181(10), 1999, pp. 3058-3068
The relevance of the mitogen-activated protein (MAP) kinase Hog1p in Candid
a albicans was addressed through the characterization of C, albicans strain
s without a functional HOG1 gene. Analysis of the phenotype of hog1 mutants
under osmostressing conditions revealed that this mutant displays a set of
morphological alterations as the result of a failure to complete the final
stages of cytokinesis, with parallel defects in the budding pattern. Even
under permissive conditions, hog1 mutants displayed a different susceptibil
ity to some compounds such as nikkomycin Z or Congo red, which interfere wi
th cell wall functionality. In addition, the hog1 mutant displayed a colony
morphology different from that of the wild-type strain on some media which
promote morphological transitions in C. albicans. We show that C. albicans
hog1 mutants are derepressed in the serum-induced hyphal formation and, co
nsistently with this behavior, that HOG1 overexpression in Saccharomyces ce
revisiae represses the pseudodimorphic transition. Most interestingly, dele
tion of HOG1 resulted in a drastic increase in the mean survival time of sy
stemically infected mice, supporting a role for this MAP kinase pathway in
virulence of pathogenic fungi. This finding has potential implications in a
ntifungal therapy.