The objective of this proposal is to define mechanisms coupling ATP-sensitive K+ (KATP) channels with myocardial energetics, and translate this information into understanding principles of endogenous cardio-protection. KATP channels are unique sensors of the cellular metabolic state, and channel function has been associated with cardioprotection in ischemic preconditioning. However, the mechanisms that couple KATP channels with cellular energetics are unknown. We have discovered that KATP channels possess ATPase and adenylate kinase-like activities, and are regulated by cellular phosphotransfer reactions. Ischemic preconditioning induces re-distribution of nucleotide fluxes among phosphotransfer systems, comprised of creatine kinase, adenylate kinase and glycolytic enzymes. Transgenic muscles, lacking phosphotransfer enzymes, are more vulnerable to metabolic stress. Based on these findings, we put forward a new concept that KATP channel regulation is accomplished by intrinsic catalysis of nucleotide exchange, and coupled to cellular energetics through phosphotransfer reactions. We hypothesize that, in metabolic stress, re-distribution of phosphoryl flux is sensed by KATP channels, and underlies cardioprotective energetic remodeling of the myocardium. Here, we will define: 1) whether KATP channel subunits possess intrinsic ATPase and/or adenylate kinase-like activities; 2) whether metabolic state-dependent distribution of phosphoryl flux regulates nucleotide exchange and catalytic activities in KATP channel subunits and synchronizes channel function with cellular energetics; and 3) whether phosphotransfer reactions, coupled with KATP channel catalytic activities, contribute to ischemic preconditioning. We will use advanced molecular biology, biochemical and electrophysiological techniques to characterize nucleotide exchange, protein-protein interaction, and catalytic activity in channel subunits, in conjunction with mass spectrometric and 31P NMR techniques to measure cellular phosphoryl fluxes using 18O isotopes, and patch-clamp channel recording in normal, pre-conditioned and phosphotransfer enzyme-deficient transgenic hearts. This proposal has the potential to establish a novel principle of KATP channel regulation by intrinsic catalysis of nucleotide exchange coupled through phosphotransfer reactions to cellular energetics. Such concept is of fundamental importance in channel biology, and essential to understand cellular regulation and protection under metabolic stress.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL064822-01
Application #
6091474
Study Section
Cardiovascular and Pulmonary Research A Study Section (CVA)
Project Start
2000-04-01
Project End
2004-03-31
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
1
Fiscal Year
2000
Total Cost
$282,200
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
City
Rochester
State
MN
Country
United States
Zip Code
55905
Yamada, Satsuki; Arrell, D Kent; Martinez-Fernandez, Almudena et al. (2015) Regenerative Therapy Prevents Heart Failure Progression in Dyssynchronous Nonischemic Narrow QRS Cardiomyopathy. J Am Heart Assoc 4:
Terzic, Andre; Alekseev, Alexey E; Yamada, Satsuki et al. (2011) Advances in cardiac ATP-sensitive K+ channelopathies from molecules to populations. Circ Arrhythm Electrophysiol 4:577-85
Arrell, D Kent; Zlatkovic Lindor, Jelena; Yamada, Satsuki et al. (2011) K(ATP) channel-dependent metaboproteome decoded: systems approaches to heart failure prediction, diagnosis, and therapy. Cardiovasc Res 90:258-66
Park, Sungjo; Terzic, Andre (2010) Quaternary structure of KATP channel SUR2A nucleotide binding domains resolved by synchrotron radiation X-ray scattering. J Struct Biol 169:243-51
Alekseev, Alexey E; Reyes, Santiago; Yamada, Satsuki et al. (2010) Sarcolemmal ATP-sensitive K(+) channels control energy expenditure determining body weight. Cell Metab 11:58-69
Olson, Timothy M; Terzic, Andre (2010) Human K(ATP) channelopathies: diseases of metabolic homeostasis. Pflugers Arch 460:295-306
Zlatkovic-Lindor, Jelena; Arrell, D Kent; Yamada, Satsuki et al. (2010) ATP-sensitive K(+) channel-deficient dilated cardiomyopathy proteome remodeled by embryonic stem cell therapy. Stem Cells 28:1355-67
Reyes, Santiago; Park, Sungjo; Terzic, Andre et al. (2010) K(ATP) channels process nucleotide signals in muscle thermogenic response. Crit Rev Biochem Mol Biol 45:506-19
Reyes, Santiago; Park, Sungjo; Johnson, Bruce D et al. (2009) KATP channel Kir6.2 E23K variant overrepresented in human heart failure is associated with impaired exercise stress response. Hum Genet 126:779-89
Yamada, Satsuki; Nelson, Timothy J; Behfar, Atta et al. (2009) Stem cell transplant into preimplantation embryo yields myocardial infarction-resistant adult phenotype. Stem Cells 27:1697-705

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