|
|
||||||||
Department of Biomolecular Sciences, UMIST, PO Box 88, Manchester M60 1QD, UK
Correspondence
Lubomira I. Stateva
lubomira.stateva{at}umist.ac.uk
The cAMP-dependent pathway, which regulates yeast-to-hypha morphogenesis in Candida albicans, is controlled by changes in cAMP levels determined by the processes of synthesis and hydrolysis. Both low- and high-affinity cAMP phosphodiesterases are encoded in the C. albicans genome. CaPDE2, encoding the high-affinity cAMP phosphodiesterase, has been cloned and shown to be toxic in Saccharomyces cerevisiae upon overexpression under pGAL1, but functional under the moderate pMET3. Deletion of CaPDE2 causes elevated cAMP levels and responsiveness to exogenous cAMP, higher sensitivity to heat shock, severe growth defects at 42 °C and highly reduced levels of EFG1 transcription. In vitro in hypha-inducing liquid medium CaPDE2, deletion prohibits normal hyphal, but not pseudohyphal growth. On solid medium capde2 mutants form aberrant hyphae, with fewer branches and almost no lateral buds, which are deficient in hypha-to-yeast reversion. The phenotypic defects of capde2 mutants show that the cAMP-dependent pathway plays specific roles in hyphal and pseudohyphal development, its regulatory role however, being greater in liquid than on solid medium in vitro. The increased expression of CaPDE2 after serum addition correlates well with a drop in cAMP levels following the initial rise in response to the hyphal inducer. These results suggest that Capde2p mediates a desensitization mechanism by lowering basal cAMP levels in response to environmental stimuli in C. albicans.
This article has been cited by other articles:
![]() |
M. Ramsdale, L. Selway, D. Stead, J. Walker, Z. Yin, S. M. Nicholls, J. Crowe, E. M. Sheils, and A. J.P. Brown MNL1 Regulates Weak Acid-induced Stress Responses of the Fungal Pathogen Candida albicans Mol. Biol. Cell, October 1, 2008; 19(10): 4393 - 4403. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Biswas, P. Van Dijck, and A. Datta Environmental Sensing and Signal Transduction Pathways Regulating Morphopathogenic Determinants of Candida albicans Microbiol. Mol. Biol. Rev., June 1, 2007; 71(2): 348 - 376. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Phillips, J. D. Crowe, and M. Ramsdale Ras pathway signaling accelerates programmed cell death in the pathogenic fungus Candida albicans PNAS, January 17, 2006; 103(3): 726 - 731. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Prasad, P. Saini, N. A. Gaur, R. A. Vishwakarma, L. A. Khan, Q. M. R. Haq, and R. Prasad Functional Analysis of CaIPT1, a Sphingolipid Biosynthetic Gene Involved in Multidrug Resistance and Morphogenesis of Candida albicans Antimicrob. Agents Chemother., August 1, 2005; 49(8): 3442 - 3452. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-Y. Cao, Y.-B. Cao, Z. Xu, K. Ying, Y. Li, Y. Xie, Z.-Y. Zhu, W.-S. Chen, and Y.-Y. Jiang cDNA Microarray Analysis of Differential Gene Expression in Candida albicans Biofilm Exposed to Farnesol Antimicrob. Agents Chemother., February 1, 2005; 49(2): 584 - 589. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. L. Jones, J. Petty, D. C. Hoyle, A. Hayes, E. Ragni, L. Popolo, S. G. Oliver, and L. I. Stateva Transcriptome profiling of a Saccharomyces cerevisiae mutant with a constitutively activated Ras/cAMP pathway Physiol Genomics, December 16, 2003; 16(1): 107 - 118. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |