title: Calcineurin mediates inhibition by FK506 and cyclosporin of recovery from alpha-factor arrest in yeast.
abstract: The structurally unrelated immunosuppressants FK506 and cyclosporin A (CsA) act similarly, inhibiting a Ca(2+)-dependent signal required for interleukin-2 transcription and T-cell activation. Each drug binds to its cytosolic receptor, FKBP-12 and cyclophilin, respectively, and the drug-receptor complexes inhibit the Ca2+/calmodulin-dependent protein phosphatase, calcineurin. In yeast, calcineurin has been implicated in recovery from alpha-mating factor arrest. Here we show that FK506 bound to yeast FKBP-12 appears to form a complex with yeast calcineurin. Moreover, recovery from mating factor arrest is highly sensitive to FK506 or CsA, and this sensitivity requires the presence of FKBP-12 or cyclophilin, respectively. These results define a key physiological target of an FK506- and CsA-sensitive signal pathway in yeast, suggest a high degree of mechanistic conservation with mammalian cells, and indicate that further examination of the yeast system should provide insight into the same process in T cells.
mesh_terms: D000483:Alleles; D019703:Calcineurin; D002148:Calmodulin-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology*; D004271:DNA, Fungal / Q000235:genetics; D005800:Genes, Fungal; D006238:Haploidy; D046911:Macromolecular Substances; D000072235:Mating Factor; D010455:Peptides / Q000235:genetics*; D010675:Pheromones / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D016559:Tacrolimus / Q000494:pharmacology*; D022021:Tacrolimus Binding Proteins
chemical_list: D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D004271:DNA, Fungal; D046911:Macromolecular Substances; D010455:Peptides; D010675:Pheromones; D000072235:Mating Factor; D016572:Cyclosporine; D019703:Calcineurin; D010749:Phosphoprotein Phosphatases; D022021:Tacrolimus Binding Proteins; D016559:Tacrolimus