The MAP kinase-activated protein kinase Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen Candida albicans.
Rck2p is the Hog1p-MAP kinase-activated protein kinase required for the attenuation of protein synthesis in response to an osmotic challenge in Saccharomyces cerevisiae. Rck2p also regulates rapamycin sensitivity in both S. cerevisiae and Candida albicans. In this study, we demonstrate that the deletion of CaRCK2 renders C. albicans cells sensitive to, and CaRck2p translocates from the cytosol to the nucleus in response to, cell wall stresses caused by Congo red, Calcoflor White, elevated heat and zymolyase. However, the kinase activity of CaRck2p is not required for the cellular response to these cell wall stresses. Furthermore, transcripts of cell wall protein-encoding genes CaBGL2, CaHWP1 and CaXOG1 are reduced in C. albicans cells lacking CaRCK2. The deletion of CaRCK2 also reduces the in vitro filamentation of C. albicans and its virulence in a mouse model of systemic candidasis. The kinase activity of CaRck2p is required for the virulence, but not for the in vitro filamentation, in C. albicans. Therefore, Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen C. albicans.
Li
Xichuan
X
Laboratory of Molecular Microbiology, Tianjin Research Center of Medical Sciences, Tianjin Medical University, Tianjin, China.
Du
Wei
W
Zhao
Jingwen
J
Zhang
Lilin
L
Zhu
Zhiyan
Z
Jiang
Linghuo
L
D000818:Animals; D001557:Benzenesulfonates / Q000633:toxicity; D002176:Candida albicans / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology* / Q000528:radiation effects; D002177:Candidiasis / Q000382:microbiology; D002467:Cell Nucleus / Q000737:chemistry; D002473:Cell Wall / Q000378:metabolism*; D003224:Congo Red / Q000633:toxicity; D003600:Cytosol / Q000737:chemistry; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000633:toxicity; D006358:Hot Temperature; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009997:Osmotic Pressure; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013312:Stress, Physiological; D016019:Survival Analysis; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis*
D001557:Benzenesulfonates; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D037521:Virulence Factors; D003224:Congo Red; C007061:C.I. Fluorescent Brightening Agent 28; C407464:RCK2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D004693:Glucan Endo-1,3-beta-D-Glucosidase