Regulation of white-opaque switching in Candida albicans

  title={Regulation of white-opaque switching in Candida albicans},
  author={Joachim Morschh{\"a}user},
  journal={Medical Microbiology and Immunology},
  • J. Morschhäuser
  • Published 14 April 2010
  • Biology
  • Medical Microbiology and Immunology
The yeast Candida albicans is part of the microflora in most healthy people, but can become a pathogen when host defenses are compromised. The phenotypic plasticity of C. albicans, which includes switching between different morphologies, contributes to its ability to colonize and infect virtually all body locations. A particularly fascinating developmental program is white-opaque switching, a reversible transition between the normal yeast morphology (white) and an elongated cell type (opaque… 

White-Opaque Switching of Candida albicans Allows Immune Evasion in an Environment-Dependent Fashion

The results suggest that, depending on the environment, white-opaque switching enables C. albicans to escape from specific host defense mechanisms.

MTL–Independent Phenotypic Switching in Candida tropicalis and a Dual Role for Wor1 in Regulating Switching and Filamentation

An expanded role is demonstrated for C. tropicalis Wor1, including the regulation of processes necessary for infection of the mammalian host, in light of the ancestral role of Wor1 as a transcriptional regulator of the transition between yeast form and filamentous growth.

N-Acetylglucosamine Induces White-to-Opaque Switching and Mating in Candida tropicalis, Providing New Insights into Adaptation and Fungal Sexual Evolution

It is shown that Candida tropicalis, another important human opportunistic pathogen, undergoes reversible and heritable phenotypic switching, referred to as the “white-opaque” transition, and that host chemical signals may facilitate this phenotypes switching and mating of C. tropicalis.

A Set of Diverse Genes Influence the Frequency of White-Opaque Switching in Candida albicans

The results suggest that the major effect of Cek1 on white-opaque switching occurs through the cell wall damage response pathway, and the genes identified serve as entry points to understand new aspects of this morphological transition.

Candida albicans white and opaque cells exhibit distinct spectra of organ colonization in mouse models of infection

It is found that white cells outcompeted opaque cells in many niches; however, it is shown for the first time that in some organs, opaque cells competed favorably with white cells and, when injected on their own, could colonize these organs.

Ssn6 Defines a New Level of Regulation of White-Opaque Switching in Candida albicans and Is Required For the Stochasticity of the Switch

This work identifies Ssn6, the C. albicans functional homolog of the Saccharomyces cerevisiae transcriptional corepressor Cyc8, as a new regulator of white-opaque switching, a new level of regulation of an important epigenetic switch in the predominant fungal pathogen of humans.

A population shift between two heritable cell types of the pathogen Candida albicans is based both on switching and selective proliferation

It is found that both opaque-to-white switching and selective white cell proliferation are required for entire populations to shift from opaque to white, and the switching frequency correlates with the preference of the resulting cell type for the growth medium.

Activation of the Cph1-Dependent MAP Kinase Signaling Pathway Induces White-Opaque Switching in Candida albicans

Screening of this library of strains showed that a hyperactive form of Ste11 lacking its N-terminal domain efficiently stimulated white cells to switch to the opaque phase, a behavior that did not occur in response to pheromone.

A Novel Function for Hog1 Stress-Activated Protein Kinase in Controlling White-Opaque Switching and Mating in Candida albicans

A novel role is revealed for the Hog1 SAPK pathway in regulating white-opaque switching and sexual behavior in C. albicans, which is responsible for half of all clinical infections in immunocompromised patients.

Regulation of white and opaque cell‐type formation in Candida albicans by Rtt109 and Hst3

It is shown that deletion of RTT109, encoding the acetyltransferase for histone H3K56, impairs stochastic and environmentally stimulated white‐opaque switching in Candida albicans, and the Hst3 level is downregulated in the presence of genotoxins and ectopic expression of HST3 blocks genotoxin induced switching.



Environmental Induction of White–Opaque Switching in Candida albicans

It is found that in strain WO-1, a strain in which genomic alterations have occurred, but not in other tested strains, switching from the white to the opaque phase can also be induced by environmental conditions, demonstrating that switching and mating of C. albicans may occur with high efficiency in appropriate niches within its human host.

Stress-induced phenotypic switching in Candida albicans.

A model for how changes in cellular growth modulate white-opaque switching frequencies is proposed, based on the sensitivity of the switch to levels of the master regulator Wor1, which shows a wide range of factors induces high rates of switching from white to opaque.

White-opaque switching in Candida albicans.

Epigenetic properties of white–opaque switching in Candida albicans are based on a self-sustaining transcriptional feedback loop

It is shown that in opaque cells, Wor1 forms a positive feedback loop: It binds its own DNA regulatory region and activates its own transcription leading to the accumulation of high levels of Wor1, and this feedback loop is self-sustaining.

The white-phase-specific gene WH11 is not required for white-opaque switching in Candida albicans

The WH11 gene is not required for phenotypic switching, and its protein product seems to have other roles in white cells, which are dispensable after the switch to the opaque phase.

Bistable expression of WOR1, a master regulator of white–opaque switching in Candida albicans

Wor1 (white–opaque regulator 1) is identified as a master regulator of white-opaque switching and genetic evidence for feedback regulation of WOR1 transcription is presented, explaining the bistable and stochastic nature of white–opaques switching.

Control of White-Opaque Phenotypic Switching inCandida albicans by the Efg1p Morphogenetic Regulator

Evidence is presented that phenotypic switching in Candida albicans is regulated by the Efg1 protein, which is known as an essential element of hyphal development (dimorphism), and results suggest that high EFG1expression levels induce and maintain the white cell form while lowEFG1 expression levels induceand maintain the opaque cell form.

Candida albicans MTLα tup1Δ mutants can reversibly switch to mating‐competent, filamentous growth forms

Although deletion of TUP1 in C. albicans MTLα cells affects cellular morphology and gene expression patterns, the mutants can still reversibly switch between mating‐competent and ‐incompetant cell types and mate with a partner of the opposite mating type.