Sensing Extracellular Signals in Cryptococcus neoformans
Journal
Cryptococcus: From Human Pathogen to Model Yeast
Part Of
Cryptococcus: From Human Pathogen to Model Yeast
Start Page
175
End Page
187
ISBN (of the container)
9781683671220
9781555816858
9781555815011
Date Issued
2014-04-09
Author(s)
Abstract
The chapter describes the abilities of Cryptococcus neoformans to sense and adapt to a subset of environmental conditions it encounters. The mechanisms for sensing extracellular signals such as stress, light, nitrogen, carbon dioxide, and oxygen are emerging. There are several future paths toward understanding the light responses of C. neoformans. First, the functions of the opsin and phytochrome in light sensing, if any, are currently unknown. Second, the conformational effects of light on the white collar complex are also unknown in C. neoformans or in detail from any fungal system since the proteins are notoriously difficult to purify in abundance for structural and other studies. Third, the genes that are regulated by light remain to be fully elucidated, although this is being addressed through transcript profiling microarray and genetic screens, particularly since these genes should control C. neoformans ability to proliferate in the wild and cause disease in humans. The current model of the CO2-sensing system in C. neoformans suggests that under limiting concentrations this molecule diffuses into the cell and is subsequently hydrated to HCO3 - and fixed inside the cell by the CA Can2p. Analysis of deletion mutants identified two genes in addition to SRE1 and SCP1 that were required for full growth under hypoxic conditions. It is of interest to note that mutation of SRE1 and SCP1 leads to an increased sensitivity to ROS, which led Ingavale et al. to propose that there is a link in oxygen sensing between hypoxia, mitochondrial function, and ROS generation.
Subjects
Cryptococcus neoformans
Extracellular signal
High-osmolarity glycerol response pathway
Hypoxia
Quorum sensing
SDGs
Publisher
ASM Press
Type
book part