Functional effects of protein kinases and peroxynitrite on cardiac carnitine palmitoyltransferase-1 in isolated mitochondria.

TitleFunctional effects of protein kinases and peroxynitrite on cardiac carnitine palmitoyltransferase-1 in isolated mitochondria.
Publication TypeJournal Article
Year of Publication2010
AuthorsSharma, V, Abraham, T, So, A, Allard, MF, McNeill, JH
JournalMol Cell Biochem
Volume337
Issue1-2
Pagination223-37
Date Published2010 Apr
ISSN1573-4919
KeywordsAnimals, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Carnitine O-Palmitoyltransferase, Cell Fractionation, Cyclic AMP-Dependent Protein Kinases, Dose-Response Relationship, Drug, In Vitro Techniques, Male, Malonyl Coenzyme A, Mitochondria, Heart, Nitroprusside, Oncogene Protein v-akt, p38 Mitogen-Activated Protein Kinases, Peroxynitrous Acid, Phosphorylation, Protein Kinases, Rats, Rats, Wistar, Tissue Distribution
Abstract

We have previously shown that metoprolol can inhibit carnitine palmitoyltransferase-1 catalytic activity and decrease its malonyl CoA sensitivity within 30 min, suggesting the importance of a covalent modification. The aim of this study was to characterize the effects of PTMs on CPT-1 in the heart. Mitochondria were isolated from the hearts of male Wistar rats and incubated with kinases of interest (protein kinase A, CAMK-II, p38 MAPK, Akt) or with peroxynitrite and sodium nitroprusside. PKA decreased CPT-1 malonyl CoA sensitivity, associated with phosphorylation of CPT-1A, whereas CAMK-II increased malonyl CoA sensitivity by phosphorylating CPT-1B. p38 bound to CPT-1B and stimulated CPT-1 activity. The association of CPT-1 with these kinases and their scaffolding proteins was confirmed in co-localization studies. Peroxynitrite and sodium nitroprusside reversibly stimulated CPT-1 activity, and the change in CPT-1B activity was most consistently associated with glutathiolation of CPT-1B. These studies have identified a new regulatory system of kinases, scaffolding proteins and thiol redox chemistry which can control cardiac CPT-1 in vitro.

DOI10.1007/s11010-009-0303-2
Alternate JournalMol. Cell. Biochem.
PubMed ID19862603
Grant List / / Canadian Institutes of Health Research / Canada