Importance of the propeptide in the biosynthetic maturation of rat cathepsin C
| Autor: | Francis Mainferme, Virginie Santilman, Michel Jadot |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Histology
Glycosylation Cathepsin D Cathepsin E Biology Cathepsin A Cathepsin B Cathepsin C Pathology and Forensic Medicine Cathepsin O Mannose 6-phosphate Propeptide Cathepsin H Cathepsin L1 Animals Point Mutation Amino Acid Sequence Tryptophan Cell Biology General Medicine Rats Protein Subunits Protein Transport Eukaryotic Cells Biochemistry COS Cells Lysosomes Peptides |
| Zdroj: | European journal of cell biology. 81(12) |
| ISSN: | 0171-9335 |
| Popis: | Summary Cathepsin C is a cysteine dipeptidyl-aminopeptidase. Active cathepsin C is found in lysosomes as a 200-kDa multimeric enzyme. Subunits constituting this assembly all arise from the proteolytic cleavage of a single precursor giving rise to three peptides: the propeptide, the α- and the β-chains. Some features of the propeptide such as its length, its high level of glycosylation and its retention in the active lysosomal form of the enzyme suggest an important contribution of the proregion in the transport, maturation and expression of cathepsin C. In order to assess some aspects of this contribution, we transiently expressed mutant molecules of rat cathepsin C either lacking three of the four glycosylation sites, partially deleted in the proregion, or mutated at tryptophan 39 also located in the proregion, and studied their biosynthesis. Our results show that at least one of the three glycosylation sites in the propeptide must be glycosylated in order to obtain targeting and maturation of cathepsin C. We also show that a deletion of 14 amino acids and mutation W39S in the propeptide totally abolishes the biosynthetic processing of the enzyme. These results demonstrate that in addition to its role as a chaperone or in maintaining the latency of the enzymatic activity, the propeptide is required for proper transport and expression of newly synthesized cathepsin C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect