Abstract
Saccharomyces cerevisiae Ste24p is a multispanning membrane protein implicated in the CAAX proteolysis step that occurs during biogenesis of the prenylated a-factor mating pheromone. Whether Ste24p acts directly as a CAAX protease or indirectly to activate a downstream protease has not yet been established. In this study, we demonstrate that purified, detergent-solubilized Ste24p directly mediates CAAX proteolysis in a zinc-dependent manner. We also show that Ste24p mediates a separate proteolytic step, the first NH(2)-terminal cleavage in a-factor maturation. These results establish that Ste24p functions both as a bona fide COOH-terminal CAAX protease and as an a-factor NH(2)-terminal protease. Importantly, this study is the first to directly demonstrate that a eukaryotic multispanning membrane protein can possess intrinsic proteolytic activity.
Publication types
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Catalysis
-
Detergents / pharmacology
-
Dose-Response Relationship, Drug
-
Endopeptidase K / metabolism
-
Endopeptidases / metabolism
-
Genotype
-
Mass Spectrometry
-
Mating Factor
-
Membrane Proteins / metabolism*
-
Metalloendopeptidases / metabolism*
-
Methylation
-
Models, Biological
-
Molecular Sequence Data
-
Peptides / metabolism*
-
Plasmids / metabolism
-
Proprotein Convertases
-
Protein Binding
-
Protein Precursors / metabolism*
-
Protein Prenylation
-
Protein Structure, Tertiary
-
Saccharomyces cerevisiae / metabolism*
-
Saccharomyces cerevisiae Proteins*
-
Sequence Homology, Amino Acid
-
Zinc / metabolism
-
Zinc / pharmacology
Substances
-
Detergents
-
Membrane Proteins
-
Peptides
-
Protein Precursors
-
Saccharomyces cerevisiae Proteins
-
Mating Factor
-
Endopeptidases
-
Proprotein Convertases
-
Endopeptidase K
-
RCE1 protein, S cerevisiae
-
Metalloendopeptidases
-
STE24 protein, S cerevisiae
-
Zinc