Cardiac ATP-sensitive K+ (KATP) channels, formed by the pore-forming Kir6.2 and regulatory SUR2A subunits, are characterized by nucleotide-dependent regulation that allows the channel complex to adjust membrane excitability in response to changes in the cellular energetic state. However, it is unknown how cardiac KATP channels translate nucleotide signals into pore gating, what is the full impact of channel activity on cardiac homeostasis, and ultimately whether channel defects contribute to heart disease. In the previous funding period of this proposal we identified an ATPase activity intrinsic to the SUR2A subunit, demonstrated that deficient KATP channel function reduces cardiac tolerance to adrenergic challenge, and discovered KATP channel mutations in initial screening of patients with heart failure. Based on these findings, we here put forward the novel concept that cardiac KATP channels operate as a bi-functional channel/enzyme molecular combination serving a vital role under diverse stressors.
Aim #1 will define the molecular mechanisms governing the SUR2A catalysis-based nucleotide gating of the Kir6.2 pore.
Aim #2 will establish the impact of KATP channels on prevention of maladaptive structural remodeling, and preservation of energetic and electrical stability in the physiologically and pathologically stressed myocardium.
Aim #3 will determine the spectrum of cardiac KATP channel mutations in patients with idiopathic dilated cardiomyopathy, and define the consequences of these mutations on the KATP channel/enzyme phenotype, metabolic sensing and cell adaptation to stress. To this end, we will employ murine knockout and disease models, along with genomic specimens from an existing cohort of patients with cardiomyopathy. The complementary technologies of enzymology, electrophysiology, physiological genomics, high-throughput DNA screening and functional proteomic analysis will be applied to study the cardiac KATP channel at the organism, organ, cellular and molecular levels. Thus, this proposal will provide an integrated understanding of cardiac KATP channels in metabolic signal decoding, stress adaptation, and their impact for clinical medicine.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL064822-06
Application #
6858695
Study Section
Cardiovascular and Pulmonary Research A Study Section (CVA)
Program Officer
Przywara, Dennis
Project Start
2000-04-01
Project End
2008-03-31
Budget Start
2005-04-01
Budget End
2006-03-31
Support Year
6
Fiscal Year
2005
Total Cost
$331,875
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
006471700
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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