Identification of the N-glycosylation sites on glutamate carboxypeptidase II necessary for proteolytic activity
| Autor: | Barbara S. Slusher, Jan Sklenár, Petr Man, Pavel Šácha, Karel Bezouška, Cyril Barinka, Jan Konvalinka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Glutamate Carboxypeptidase II
Glycosylation Insecta Synaptic cleft Excitotoxicity Gene Expression medicine.disease_cause Biochemistry Article Catalysis Cell Line Carboxypeptidase activity chemistry.chemical_compound N-linked glycosylation medicine Glutamate carboxypeptidase II Animals Humans Molecular Biology Binding Sites Hydrolysis Glutamate receptor Kinetics chemistry Membrane protein Antigens Surface Mutagenesis Site-Directed |
| Popis: | Glutamate carboxypeptidase II (GCPII) is a membrane peptidase expressed in the prostate, central and peripheral nervous system, kidney, small intestine, and tumor-associated neovasculature. The GCPII form expressed in the central nervous system, termed NAALADase, is responsible for the cleavage of N-acetyl-L-aspartyl-L-glutamate (NAAG) yielding free glutamate in the synaptic cleft, and is implicated in various pathologic conditions associated with glutamate excitotoxicity. The prostate form of GCPII, termed prostate-specific membrane antigen (PSMA), is up-regulated in cancer and used as an effective prostate cancer marker. Little is known about the structure of this important pharmaceutical target. As a type II membrane protein, GCPII is heavily glycosylated. In this paper we show that N-glycosylation is vital for proper folding and subsequent secretion of human GCPII. Analysis of the predicted N-glycosylation sites also provides evidence that these sites are critical for GCPII carboxypeptidase activity. We confirm that all predicted N-glycosylation sites are occupied by an oligosaccharide moiety and show that glycosylation at sites distant from the putative catalytic domain is critical for the NAAG-hydrolyzing activity of GCPII calling the validity of previously described structural models of GCPII into question. |
| Databáze: | OpenAIRE |
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