Sgt1p contributes to cyclic AMP pathway activity and physically interacts with the adenylyl cyclase Cyr1p/Cdc35p in budding yeast.
Sgt1p is a highly conserved eucaryotic protein that is required for both SCF (Skp1p/Cdc53p-Cullin-F-box)-mediated ubiquitination and kinetochore function in yeast. We show here that Sgtlp is also involved in the cyclic AMP (cAMP) pathway in Saccharomyces cerevisiae. SGT1 is an allele-specific suppressor of cdc35-1, a thermosensitive mutation in the leucine-rich repeat domain of the adenylyl cyclase Cyrlp/Cdc35p. We demonstrate that Sgt1p and Cyrlp/Cdc35p physically interact and that the activity of the cAMP pathway is affected in an sgt1 conditional mutant. Sequence analysis suggests that Sgtlp has features of a cochaperone. Thus, Sgt1p is a novel activator of adenylyl cyclase in S. cerevisiae and may function in the assembly or the conformational activation of specific multiprotein complexes.
Dubacq
Caroline
C
Service de Biochimie et de Génétique Moléculaire, CEA/Saclay, F-91191 Gif-sur-Yvette, France.
Guerois
Raphaël
R
Courbeyrette
Régis
R
Kitagawa
Katsumi
K
Mann
Carl
C
D048868:Adaptor Proteins, Signal Transducing; D000262:Adenylyl Cyclases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D000242:Cyclic AMP / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics; D004789:Enzyme Activation; D005800:Genes, Fungal; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D048868:Adaptor Proteins, Signal Transducing; D004271:DNA, Fungal; D018832:Molecular Chaperones; D012097:Repressor Proteins; C470726:SGT1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000242:Cyclic AMP; D000262:Adenylyl Cyclases