title: Antibodies directed against a yeast carboxyl-terminal peroxisomal targeting signal specifically recognize peroxisomal proteins from various yeasts.
abstract: The carboxyl-terminal tripeptide Ala-Lys-Ile is essential for targeting Candida tropicalis trifunctional enzyme (hydratase-dehydrogenase-epimerase) to peroxisomes of both Candida albicans and Saccharomyces cerevisiae (Aitchison,J.D., Murray, W.W. and Rachubinski, R. A. (1991).J. Biol. Chem. 266, 23197-23203). We investigated the possibility that this tripeptide may act as a general peroxisomal targeting signal (PTS) for other proteins in the yeasts C. tropicalis, C. albicans, Yarrowia lipolytica and S. cerevisiae, and in rat liver. Anti-AKI antibodies raised against the carboxyl-terminal 12 amino acids of trifunctional enzyme were used to search for this PTS in proteins of these yeasts and of rat liver. The anti-AKI antibodies reacted exclusively with multiple peroxisomal proteins from the yeasts C. tropicalis, C. albicans and Y. lipolytica. There was a weak reaction of the antibodies with one peroxisomal protein from S. cerevisiae and no reaction with peroxisomal proteins from rat liver. Antibodies directed against a synthetic peptide containing a carboxyl-terminal Ser-Lys-Leu PTS (Gould, S. J., Krisans, S., Keller, G.-A. and Subramani, S. (1990). J. Cell Biol. 110,27-34) reacted with multiple peroxisomal proteins of rat liver and with peroxisomal proteins of yeast distinct from those identified with anti-AKI antibodies. These results provide evidence that several peroxisomal proteins of different yeasts contain a PTS antigenically similar to that of C. tropicalis trifunctional enzyme and that this signal is absent from peroxisomal proteins from at least one mammalian system, rat liver.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000908:Antibodies, Fungal; D000946:Antigens, Fungal / Q000737:chemistry; D002175:Candida / Q000737:chemistry / Q000276:immunology; D000939:Epitopes / Q000737:chemistry; D005656:Fungal Proteins / Q000276:immunology*; D008830:Microbodies / Q000737:chemistry / Q000276:immunology; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology; D021382:Protein Sorting Signals / Q000737:chemistry / Q000276:immunology*; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000276:immunology; D013045:Species Specificity; D015003:Yeasts / Q000737:chemistry / Q000276:immunology*
chemical_list: D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D000939:Epitopes; D005656:Fungal Proteins; D009842:Oligopeptides; D021382:Protein Sorting Signals