COP9 signalosome components play a role in the mating pheromone response of S. cerevisiae.
A family of genetically and structurally homologous complexes, the proteasome lid, Cop9 signalosome (CSN) and eukaryotic translation initiation factor 3, mediate different regulatory pathways. The CSN functions in numerous eukaryotes as a regulator of development and signaling, yet until now no evidence for a complex has been found in Saccharomyces cerevisiae. We identified a group of proteins, including a homolog of Csn5/Jab1 and four uncharacterized PCI components, that interact in a manner suggesting they form a complex analogous to the CSN in S. cerevisiae. These newly identified subunits play a role in adaptation to pheromone signaling. Deletants for individual subunits enhance pheromone response and increase mating efficiency. Overexpression of individual subunits or a human homolog mitigates sst2-induced pheromone sensitivity. Csi1, a novel CSN interactor, exhibits opposite phenotypes. Deletants also accumulate Cdc53/cullin in a Rub1-modified form; however, this role of the CSN appears to be distinct from that in the mating pathway.
Maytal-Kivity
Vered
V
Department of Biology and Institute for Catalysis Science and Technology, Technion-Israel Institute of Technology, 32000 Haifa, Israel.
Piran
Ron
R
Pick
Elah
E
Hofmann
Kay
K
Glickman
Michael H
MH
D000075686:COP9 Signalosome Complex; D018797:Cell Cycle Proteins / Q000378:metabolism; D044842:Cullin Proteins; D046912:Multiprotein Complexes; D010447:Peptide Hydrolases; D010675:Pheromones / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
C100988:Cdc53 protein, S cerevisiae; D018797:Cell Cycle Proteins; C577560:Csi1 protein, S cerevisiae; D044842:Cullin Proteins; D046912:Multiprotein Complexes; D010675:Pheromones; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex