Title: | Sxa2 is a serine carboxypeptidase that degrades extracellular P-factor in the fission yeast Schizosaccharomyces pombe |
Address: | "Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK" |
DOI: | 10.1046/j.1365-2958.2000.01855.x |
ISSN/ISBN: | 0950-382X (Print) 0950-382X (Linking) |
Abstract: | "Stimulating the fission yeast Schizosaccharomyces pombe with mating pheromones brings about responses that lead to cell conjugation. Persistent stimulation does not, however, induce a continuous response as the cells become desensitized to the presence of the pheromone. One mechanism that contributes to desensitization in M-cells is the release of a carboxypeptidase that inactivates the extracellular P-factor pheromone. Production of the carboxypeptidase requires a functional sxa2 gene. In this study, we report the first molecular characterization of the Sxa2 protein and provide direct evidence that it is the carboxypeptidase that degrades P-factor. Sxa2 is synthesized as a precursor that undergoes an internal cleavage event catalysed by a protease with specificity for basic residues. This generates a series of catalytically active N-terminal fragments and an inactive C-terminal fragment. Cleavage is essential for activation of the carboxypeptidase and, although the C-terminal fragment is inactive, it is required for the N-terminal fragment to attain activity" |
Keywords: | "Amino Acid Sequence Antibodies, Fungal Carboxypeptidases/chemistry/genetics/*metabolism Electrophoresis, Agar Gel Fungal Proteins Gene Expression Regulation, Fungal Glycosylation Histidine/immunology/metabolism Molecular Sequence Data Mutation Pheromones/;" |
Notes: | "MedlineLadds, G Davey, J eng Research Support, Non-U.S. Gov't England 2000/05/03 Mol Microbiol. 2000 Apr; 36(2):377-90. doi: 10.1046/j.1365-2958.2000.01855.x" |