@article{BoehmTorsinTintetal.2017,
  author    = {B{\"o}hm, Lena and Torsin, Sanda and Tint, Su Hlaing and Eckstein, Marie Therese and Ludwig, Tobias and P{\´e}rez, J. Christian},
  title     = {The yeast form of the fungus Candida albicans promotes persistence in the gut of gnotobiotic mice},
  series = {PLoS Pathogens},
  volume    = {13},
  journal   = {PLoS Pathogens},
  number    = {10},
  doi       = {10.1371/journal.ppat.1006699},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159120},
  pages     = {e1006699},
  year      = {2017},
  abstract  = {Many microorganisms that cause systemic, life-threatening infections in humans reside as harmless commensals in our digestive tract. Yet little is known about the biology of these microbes in the gut. Here, we visualize the interface between the human commensal and pathogenic fungus Candida albicans and the intestine of mice, a surrogate host. Because the indigenous mouse microbiota restricts C. albicans settlement, we compared the patterns of colonization in the gut of germ free and antibiotic-treated conventionally raised mice. In contrast to the heterogeneous morphologies found in the latter, we establish that in germ free animals the fungus almost uniformly adopts the yeast cell form, a proxy of its commensal state. By screening a collection of C. albicans transcription regulator deletion mutants in gnotobiotic mice, we identify several genes previously unknown to contribute to in vivo fitness. We investigate three of these regulators—ZCF8, ZFU2 and TRY4—and show that indeed they favor the yeast form over other morphologies. Consistent with this finding, we demonstrate that genetically inducing non-yeast cell morphologies is detrimental to the fitness of C. albicans in the gut. Furthermore, the identified regulators promote adherence of the fungus to a surface covered with mucin and to mucus-producing intestinal epithelial cells. In agreement with this result, histology sections indicate that C. albicans dwells in the murine gut in close proximity to the mucus layer. Thus, our findings reveal a set of regulators that endows C. albicans with the ability to endure in the intestine through multiple mechanisms.},
  language  = {en}
}
@article{MorschhaeuserRamirezZavalaWeyleretal.2013,
  author    = {Morschh{\"a}user, Joachim and Ram{\´i}rez-Zavala, Bernardo and Weyler, Michael and Gildor, Tsvia and Schmauch, Christian and Kornitzer, Daniel and Arkowitz, Robert},
  title     = {Activation of the Cph1-Dependent MAP Kinase Signaling Pathway Induces White-Opaque Switching in Candida albicans},
  series = {PLoS Pathogens},
  journal   = {PLoS Pathogens},
  doi       = {10.1371/journal.ppat.1003696},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97281},
  year      = {2013},
  abstract  = {Depending on the environmental conditions, the pathogenic yeast Candida albicans can undergo different developmental programs, which are controlled by dedicated transcription factors and upstream signaling pathways. C. albicans strains that are homozygous at the mating type locus can switch from the normal yeast form (white) to an elongated cell type (opaque), which is the mating-competent form of this fungus. Both white and opaque cells use the Ste11-Hst7-Cek1/Cek2 MAP kinase signaling pathway to react to the presence of mating pheromone. However, while opaque cells employ the transcription factor Cph1 to induce the mating response, white cells recruit a different downstream transcription factor, Tec1, to promote the formation of a biofilm that facilitates mating of opaque cells in the population. The switch from the white to the opaque cell form is itself induced by environmental signals that result in the upregulation of the transcription factor Wor1, the master regulator of white-opaque switching. To get insight into the upstream signaling pathways controlling the switch, we expressed all C. albicans protein kinases from a tetracycline-inducible promoter in a switching-competent strain. Screening of this library of strains showed that a hyperactive form of Ste11 lacking its N-terminal domain (Ste11ΔN467) efficiently stimulated white cells to switch to the opaque phase, a behavior that did not occur in response to pheromone. Ste11ΔN467-induced switching specifically required the downstream MAP kinase Cek1 and its target transcription factor Cph1, but not Cek2 and Tec1, and forced expression of Cph1 also promoted white-opaque switching in a Wor1-dependent manner. Therefore, depending on the activation mechanism, components of the pheromone-responsive MAP kinase pathway can be reconnected to stimulate an alternative developmental program, switching of white cells to the mating-competent opaque phase.},
  language  = {en}
}