Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, November 2001, p. 3037-3045, Vol. 45, No. 11
Department of
Mycology1 and Department of
Spectroscopic Analysis,2 Nippon Roche
K. K. Research Center, Kanagawa 247-8530, Japan
Received 2 October 2000/Returned for modification 13 November
2000/Accepted 14 August 2001
Sterol 14
0066-4804/01/$04.00+0 DOI: 10.1128/AAC.45.11.3037-3045.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
In Vitro and In Vivo Effects of 14
-Demethylase
(ERG11) Depletion in Candida
glabrata

and
-demethylase (ERG11) is the target
enzyme of azole antifungals that are widely used for the treatment of
fungal infections. Candida glabrata is known to be less
susceptible to fluconazole than most Candida albicans
strains, and the incidence of C. glabrata infection has
been increasing mostly in conjunction with the use of azole
antifungals. Recently, it has been reported that C.
glabrata can rescue the defect of ergosterol biosynthesis by
incorporating cholesterol from serum. To explore the effect of
inactivating Erg11p in C. glabrata, we generated mutant
strains in which the ERG11 gene was placed under the
control of tetracycline-regulatable promoters. In these mutants,
expression of the ERG11 gene can be repressed by
doxycycline (DOX). All mutants showed a growth defect in the presence
of DOX. The numbers of CFU of the mutants were lowered by only 1/10
with DOX treatment. In these mutants, accumulation of
4,14-dimethylzymosterol, which differs from an accumulated abnormal
sterol detected in C. albicans and Saccharomyces cerevisiae treated with fluconazole, was observed by DOX
treatment. Although such phenotypes were also observed in
serum-containing media by DOX treatment, they were alleviated.
Furthermore, the mutant could grow in DOX-treated mice without a severe
reduction in the number of cells. Thus, depleting the expression of the ERG11 gene lowered the number of CFU by only 1/10 due to
the accumulation of 4,14-demethylzymosterol in vitro, and it did not
result in the defective growth of fungal cells in mice. These results
suggested that Erg11p is not an ideal target molecule of antifungals
for C. glabrata.
*
Corresponding author. Present address: Department of
Oncology, Nippon Roche K. K. Research Center, 200 Kajiwara,
Kamakura, Kanagawa 247-8530, Japan. Phone: 81-467-47-2218. Fax:
81-467-45-6782. E-mail: hironobu.nakayama{at}roche.com.
Present address: Department of Chemistry, Nippon Roche K. K. Research Center, 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
Present address: Department of Oncology, Nippon Roche K. K. Research Center, 200 Kajiwara, Kamakura, Kanagawa 247-8530, Japan.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»