Back to Search
Start Over
Molecular cloning and functional expression of a human peptide methionine sulfoxide reductase (hMsrA).
- Source :
-
FEBS letters [FEBS Lett] 1999 Jul 30; Vol. 456 (1), pp. 17-21. - Publication Year :
- 1999
-
Abstract
- Oxidation of methionine residues in proteins to methionine sulfoxide can be reversed by the enzyme peptide methionine sulfoxide reductase (MsrA, EC 1.8.4.6). We cloned the gene encoding a human homologue (hMsrA) of the enzyme, which has an 88% amino acid sequence identity to the bovine version (bMsrA). With dot blot analyses based on RNA from human tissues, expression of hMsrA was found in all tissues tested, with highest mRNA levels in adult kidney and cerebellum, followed by liver, heart ventricles, bone marrow and hippocampus. In fetal tissue, expression was highest in the liver. No expression of hmsrA was detected in leukemia and lymphoma cell lines. To test if hMsrA is functional in cells, we assayed its effect on the inactivation time course of the A-type potassium channel ShC/B since this channel property strongly depends on the oxidative state of a methionine residue in the N-terminal part of the polypeptide. Co-expression of ShC/B and hMsrA in Xenopus oocytes significantly accelerated inactivation, showing that the cloned enzyme is functional in an in vivo assay system. Furthermore, the activity of a purified glutathione-S-transferase-hMsrA fusion protein was demonstrated in vitro by measuring the reduction of [3H]N-acetyl methionine sulfoxide.
- Subjects :
- Amino Acid Sequence
Animals
Cell Line enzymology
Cerebellum enzymology
Cloning, Molecular
Enzyme Activation
Female
Fetus enzymology
Gene Expression Regulation, Developmental
Humans
Kidney enzymology
Kidney growth & development
Leukemia enzymology
Liver embryology
Liver enzymology
Lung enzymology
Lymphoma enzymology
Methionine Sulfoxide Reductases
Molecular Sequence Data
Myocardium enzymology
Oocytes enzymology
Potassium Channels metabolism
Recombinant Fusion Proteins genetics
Recombinant Fusion Proteins metabolism
Sequence Homology, Amino Acid
Xenopus laevis
Oxidoreductases genetics
Oxidoreductases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0014-5793
- Volume :
- 456
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- FEBS letters
- Publication Type :
- Academic Journal
- Accession number :
- 10452521
- Full Text :
- https://doi.org/10.1016/s0014-5793(99)00917-5