TY - JOUR
T1 - Functional effects of protein kinases and peroxynitrite on cardiac carnitine palmitoyltransferase-1 in isolated mitochondria
AU - Sharma, Vijay
AU - Abraham, Thomas
AU - So, Amie
AU - Allard, Michael F.
AU - McNeill, John H.
N1 - Funding Information:
Acknowledgments We thank Dr. Suzanne Perry, Dr. Shouming He, and Ms. Kyung-Mee Moon at the Proteomics Core Facility, University of British Columbia for carrying out the mass spectrometry analyses. We also thank Dr. Leonard Foster (Department of Biochemistry and Physiology, UBC) for his valuable advice on the mass spectrometry studies. We thank Amrit Samra (iCapture centre, St. Paul’s Hospital, Vancouver) for the preparation of heart cryosections, and Mrs. Hannah Parsons for assistance with preliminary experiments. This work was supported by the Canadian Institutes of Health Research.
Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010/4
Y1 - 2010/4
N2 - 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.
AB - 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.
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U2 - 10.1007/s11010-009-0303-2
DO - 10.1007/s11010-009-0303-2
M3 - Article
C2 - 19862603
AN - SCOPUS:77949655389
SN - 0300-8177
VL - 337
SP - 223
EP - 237
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
IS - 1-2
ER -