A constitutively active GPCR governs morphogenic transitions in Cryptococcus neoformans.

Published

Journal Article

Sex in fungi is driven by peptide pheromones sensed through seven-transmembrane pheromone receptors. In Cryptococcus neoformans, sexual reproduction occurs through an outcrossing/heterothallic a- sexual cycle or an inbreeding/homothallic - unisexual mating process. Pheromone receptors encoded by the mating-type locus (MAT) mediate reciprocal pheromone sensing during opposite-sex mating and contribute to but are not essential for unisexual mating. A pheromone receptor-like gene, CPR2, was discovered that is not encoded by MAT and whose expression is induced during a- mating. cpr2 mutants are fertile but have a fusion defect and produce abnormal hyphal structures, whereas CPR2 overexpression elicits unisexual reproduction. When heterologously expressed in Saccharomyces cerevisiae, Cpr2 activates pheromone responses in the absence of any ligand. This constitutive activity results from an unconventional residue, Leu(222), in place of a conserved proline in transmembrane domain six; a Cpr2(L222P) mutant is no longer constitutively active. Cpr2 engages the same G-protein activated signalling cascade as the Ste3a/alpha pheromone receptors, and thereby competes for pathway activation. This study established a new paradigm in which a naturally occurring constitutively active G protein-coupled receptor governs morphogenesis in fungi.

Full Text

Duke Authors

Cited Authors

  • Hsueh, Y-P; Xue, C; Heitman, J

Published Date

  • May 6, 2009

Published In

Volume / Issue

  • 28 / 9

Start / End Page

  • 1220 - 1233

PubMed ID

  • 19322200

Pubmed Central ID

  • 19322200

Electronic International Standard Serial Number (EISSN)

  • 1460-2075

Digital Object Identifier (DOI)

  • 10.1038/emboj.2009.68

Language

  • eng

Conference Location

  • England