Cyclic AMP-dependent protein kinase controls virulence of the fungal pathogen Cryptococcus neoformans.

Published

Journal Article

Cryptococcus neoformans is an opportunistic fungal pathogen that infects the human central nervous system. This pathogen elaborates two specialized virulence factors: the antioxidant melanin and an antiphagocytic immunosuppressive polysaccharide capsule. A signaling cascade controlling mating and virulence was identified. The PKA1 gene encoding the major cyclic AMP (cAMP)-dependent protein kinase catalytic subunit was identified and disrupted. pka1 mutant strains were sterile, failed to produce melanin or capsule, and were avirulent. The PKR1 gene encoding the protein kinase A (PKA) regulatory subunit was also identified and disrupted. pkr1 mutant strains overproduced capsule and were hypervirulent in animal models of cryptococcosis. pkr1 pka1 double mutant strains exhibited phenotypes similar to that of pka1 mutants, providing epistasis evidence that the Pka1 catalytic subunit functions downstream of the Pkr1 regulatory subunit. The PKA pathway was also shown to function downstream of the Galpha protein Gpa1 and to regulate cAMP production by feedback inhibition. These findings define a Galpha protein-cAMP-PKA signaling pathway regulating differentiation and virulence of a human fungal pathogen.

Full Text

Duke Authors

Cited Authors

  • D'Souza, CA; Alspaugh, JA; Yue, C; Harashima, T; Cox, GM; Perfect, JR; Heitman, J

Published Date

  • May 2001

Published In

Volume / Issue

  • 21 / 9

Start / End Page

  • 3179 - 3191

PubMed ID

  • 11287622

Pubmed Central ID

  • 11287622

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/MCB.21.9.3179-3191.2001

Language

  • eng

Conference Location

  • United States