Molecular and Cellular Biochemistry

, Volume 256, Issue 1, pp 13–27

Phosphotransfer dynamics in skeletal muscle from creatine kinase gene-deleted mice

  • Petras P. Dzeja
  • Andre Terzic
  • Be Wieringa
Article

DOI: 10.1023/B:MCBI.0000009856.23646.38

Cite this article as:
Dzeja, P.P., Terzic, A. & Wieringa, B. Mol Cell Biochem (2004) 256: 13. doi:10.1023/B:MCBI.0000009856.23646.38

Abstract

To assess the significance of energy supply routes in cellular energetic homeostasis, net phosphoryl fluxes catalyzed by creatine kinase (CK), adenylate kinase (AK) and glycolytic enzymes were quantified using 18O-phosphoryl labeling. Diaphragm muscle from double M-CK/ScCKmit knockout mice exhibited virtually no CK-catalyzed phosphotransfer. Deletion of the cytosolic M-CK reduced CK-catalyzed phosphotransfer by 20%, while the absence of the mitochondrial ScCKmit isoform did not affect creatine phosphate metabolic flux. Contribution of the AK-catalyzed phosphotransfer to total cellular ATP turnover was 15.0, 17.2, 20.2 and 28.0% in wild type, ScCKmit, M-CK and M-CK/ScCKmit deficient muscles, respectively. Glycolytic phosphotransfer, assessed by G-6-P 18O-phosphoryl labeling, was elevated by 32 and 65% in M-CK and M-CK/ScCKmit deficient muscles, respectively. Inhibition of glyceraldehyde 3-phosphate dehydrogenase (GAPDH)/phosphoglycerate kinase (PGK) in CK deficient muscles abolished inorganic phosphate compartmentation and redirected high-energy phosphoryl flux through the AK network. Under such conditions, AK phosphotransfer rate was equal to 86% of the total cellular ATP turnover concomitant with almost normal muscle performance. This indicates that near-equilibrium glycolytic phosphotransfer reactions catalyzed by the GAPDH/PGK support a significant portion of the high-energy phosphoryl transfer in CK deficient muscles. However, CK deficient muscles displayed aberrant AT-Pase-ATPsynthase communication along with lower energetic efficiency (P/O ratio), and were more sensitive to metabolic stress induced by chemical hypoxia. Thus, redistribution of phosphotransfer through glycolytic and AK networks contributes to energetic homeostasis in muscles under genetic and metabolic stress complementing loss of CK function.

energy metabolismmetabolic networksadenylate kinaseglycolysisgene knockout18O- phosphoryl exchange

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Petras P. Dzeja
    • 1
    • 2
  • Andre Terzic
    • 2
  • Be Wieringa
    • 3
  1. 1.Department of BiochemistryUniversity of MinnesotaMinneapolisUSA
  2. 2.Division of Cardiovascular Diseases, Departments of Medicine and Molecular Pharmacology and Experimental TherapeuticsMayo ClinicRochesterUSA
  3. 3.Department of Cell BiologyNCMLS University Medical Center, University of NijmegenThe Netherlands