An Atypical Protein Disulfide Isomerase from the Protozoan Parasite Leishmania Containing a Single Thioredoxin-like Domain
| Autor: | Robert Noiva, Alejandro Padilla, Nancy Lee, Ketha V. K. Mohan, Alain Debrabant, Hira L. Nakhasi |
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| Rok vydání: | 2003 |
| Předmět: |
Immunoblotting
Molecular Sequence Data Protein domain Protein Disulfide-Isomerases Isomerase Biochemistry Thioredoxins Animals Humans Amino Acid Sequence Protein disulfide-isomerase Molecular Biology Secretory pathway DNA Primers chemistry.chemical_classification Base Sequence Sequence Homology Amino Acid biology Reverse Transcriptase Polymerase Chain Reaction Endoplasmic reticulum Active site Cell Biology Cell biology Secretory protein Enzyme chemistry biology.protein Electrophoresis Polyacrylamide Gel Leishmania donovani |
| Zdroj: | Journal of Biological Chemistry. 278:1872-1878 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m210322200 |
| Popis: | In higher eukaryotes, secretory proteins are under the quality control of the endoplasmic reticulum for their proper folding and release into the secretory pathway. One of the proteins involved in the quality control is protein disulfide isomerase, which catalyzes the formation of protein disulfide bonds. As a first step toward understanding the endoplasmic reticulum quality control of secretory proteins in lower eukaryotes, we have isolated a protein disulfide isomerase gene from the protozoan parasite Leishmania donovani. The parasite enzyme shows high sequence homology with homologs from other organisms. However, unlike the four thioredoxin-like domains found in most protein disulfide isomerases, of which two contain an active site, the leishmanial enzyme possesses only one active site present in a single thioredoxin-like domain. When expressed in Escherichia coli, the recombinant parasite enzyme shows both oxidase and isomerase activities. Replacement of the two cysteins with alanines in its active site results in loss of both enzymatic activities. Further, overexpression of the mutated/inactive form of the parasite enzyme in L. donovani significantly reduced their release of secretory acid phosphatases, suggesting that this single thioredoxin-like domain protein disulfide isomerase could play a critical role in the Leishmania secretory pathway. |
| Databáze: | OpenAIRE |
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