Global regulatory roles of the cAMP/PKA pathway revealed by phenotypic, transcriptomic and phosphoproteomic analyses in a null mutant of the PKA catalytic subunit in Candida albicans. Issue 1 (24th April 2017)

• Record Type: Journal Article
• Authors: Cao, Chengjun; Wu, Mei; Bing, Jian; Tao, Li; Ding, Xuefen; Liu, Xiaoyun; Huang, Guanghua
• Is Part Of: Molecular microbiology. Volume 105:Issue 1(2017)
• Page Start: 46
• Page End: 64
• Publication Date: 2017-04-24
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13681
• Languages: English
• ISSNs: 0950-382X

Abstract

Summary: The conserved cAMP‐dependent protein kinase (PKA) plays critical roles in the regulation of morphological transitions and virulence in the human fungal pathogen Candida albicans . It has long been thought that the PKA catalytic subunit is essential for cell viability in this fungus. Paradoxically, the single adenylyl cyclase‐encoding gene, CYR1, which is required for the production of cAMP in C. albicans, is not essential for cell growth. Here, a double mutant of TPK1 and TPK2 ( tpk2/tpk2 tpk1/tpk1, t2t1 ), which encode two isoforms of the PKA catalytic subunit was successfully generated, suggesting that this subunit is not essential for cell viability. Inactivation of the PKA catalytic subunit blocked filamentation and dramatically attenuated white‐to‐opaque switching, but promoted sexual mating. Comparative transcriptomic analyses demonstrated that the t2t1 and cyr1/cyr1 mutants exhibited similar global gene expression profiles. Compared with the WT strain, the general transcriptional activity and metabolism were significantly decreased in both the t2t1 and cyr1/cyr1 mutants. Using combined phosphoproteomic and bioinformatic analyses, we identified 181 potential PKA phosphorylation targets, which represent 148 unique proteins involved in a wide spectrum of biological processes. The study sheds new insights into the global regulatory features of the cAMP/PKA pathway in C. albicans . Abstract : The human fungal pathogen Candida albicans causes both superficial and life‐threatening infections in immunocompromised people. In this study, we generated a null mutant of the PKA catalytic subunit, a central regulator of virulence in C. albicans . Phenotypic, transcriptomic and phosphoproteomic analyses indicate that the cAMP/PKA signaling pathway plays global regulatory roles in a number of basic biological processes, including morphological transitions and sexual mating, in C. albicans .