Mycobiology.  2011 Dec;39(4):249-256.

pH Response Pathways in Fungi: Adapting to Host-derived and Environmental Signals

• Selvig K
• Alspaugh J

Abstract

Microorganisms are significantly affected when the ambient pH of their environment changes. They must therefore be able to sense and respond to these changes in order to survive. Previous investigators have studied various fungal species to define conserved pH-responsive signaling pathways. One of these pathways, known as the Pal/Rim pathway, is activated in response to alkaline pH signals, ultimately targeting the PacC/Rim101 transcription factor. Although the central signaling components are conserved among divergent filamentous and yeast-like fungi, there is some degree of signaling specificity between fungal species. This specificity exists primarily in the downstream transcriptional targets of this pathway, likely allowing differential adaptation to species-specific environmental niches. In this review, the role of the Pal/Rim pathway in fungal pH response is discussed. Also highlighted are functional differences present in this pathway among human fungal pathogens, differences that allow these specialized microorganisms to survive in the various micro-environments of the infected human host.

Keyword

Aspergillus nidulans; Candida albicans; Cryptococcus neoformans; PacC; Rim101; Saccharomyces cerevisiae; Signal transduction; Yeast

MeSH Terms

Aspergillus nidulans
Candida albicans
Cryptococcus neoformans
Fungi
Humans
Hydrogen-Ion Concentration
Research Personnel
Saccharomyces cerevisiae
Sensitivity and Specificity
Signal Transduction
Transcription Factors
Yeasts
Transcription Factors