Edward M. Balog, Ph.D.

Assistant Professor

School of Applied Physiology
Phone: (404) 894-3957 (office)
email: ed.balog@ap.gatech.edu
Lab: Ryanodine Receptor Laboratory

Balog

Education

  • Furman University B.A. Exercise Science 1983
  • University of South Carolina M.S. Exercise Physiology 1988
  • Marquette University Ph.D. Physiology 1994

Research Interests

I am currently studying a class of intracellular ion channels know as ryanodine receptors (RyRs). In mammals, there are three RyR isoforms. RyR1 and RyR2 are the predominate isoforms in skeletal and cardiac muscle, respectively where they are the primary efflux pathway for the release of calcium from the sarcoplasmic reticulum to activate contraction. RyR3 has a wide tissue distribution and contributes to calcium regulation in a variety of cell types. RyRs are the largest known ion channel and are regulated by a multitude of endogenous effectors, including calcium, magnesium, adenine nucleotides, reactive oxygen and nitrogen species, accessory proteins such as calmodulin, FK506 binding protein, phosphatases, kinases, and even the L-type calcium channel, to name a few. Thus altering the sensitivity of the channel to regulators and/or changing the intracellular concentration of effector would impact RyR channel function, sarcoplasmic reticulum calcium release and modify muscle function. Therefore, an area of interest is the regulation of these channels by endogenous effectors; especially as it relates to altered contractile function associated with cardiac ischemia/reperfusion, skeletal muscle fatigue and aging.

Because of their central role in cellular calcium regulation, defects in RyR channels can lead to potentially fatal disorders. Mutations in RyR1 give rise to the pharmacogenetic disorder, malignant hyperthermia (MH). Recently RyR2 mutations have been identified in catecholaminergic polymorphic ventricular tachycardia (CPVT) and arrhythmogenic right ventricular dysplasia (ARVD) affected individuals. Interestingly, the mutations linked to CPVT and ARVD occur in the regions of RyR2 corresponding to the mutation-rich regions of RyR1 leading to MH. We are interested in determining the molecular mechanisms by which these mutations alter RyR channel function. No pathology has been linked to mutations in RyR3, yet.

We analyze channel function on multiples levels of organization. Sarcoplasmic reticulum vesicle [3H]ryanodine binding is used to examine large populations of channels. We incorporate channels into artificial lipid bilayers in order to record single channel currents and assess channel kinetics. Calcium release from permeabilized muscle fibers provides a method of examining RyR function in situ. My research has two long-range goals. The first is to understand how intracellular calcium is regulated and how alterations in the regulation effects cell function. The second goal is to understand the RyR regulatory sites that could potentially be exploited for the development of pharmacological compounds to treat disorders of cellular calcium regulation.

Classes

Select Publications

  • Jiang, J., Zhou, Y ., Zou, J., Chen, Y., Patel, P., Yang, J.J. and Balog, E.M. Site-Specific Modification of Calmodulin Ca2+ Affinity Tunes the Skeletal Muscle Ryanodine Receptor Activation Profile. J. Biol. Chem., In Review 2009.
  • Corona, B., Balog, E ., Doyle, J., Rupp, J., Luke, R., and Ingalls, C. Junctophilin Damage Contributes To Early Strength Deficits And EC Coupling Failure After Eccentric Contractions. Am J Physiol Cell, In Review 2009.
  • Balog EM, Lockamy EL, Thomas DD, Ferrington DA. Site-Specific Methionine Oxidation Initiates Calmodulin Degradation by the 20S Proteasome. Biochemistry. 48:3005-3016, 2009
  • Balog, E.M. Calcium channels and skeletal muscle fatigue. In: Advances in Neuromuscular Physiology of Motor Skills and Muscle Fatigue. M. Shinohara, ed., Research Signposts; Kerala. In Press 2009.
  • Kampfer, A.J. and E.M. Balog. S-Adenosyl-L-Methionine Activates the Cardiac Ryanodine Receptor. Biochem. Biophys. Res. Comm. 371:606-609, 2008.
  • Balog, E.M., L. Norton, R.A. Bloomquist, C.F. Louis, D.D. Thomas, and B.R. Fruen. Methionine residues critical for regulation of the cardiac SR Ca2+ release channel. Am. J. Physiol. Heart Circ. Physiol. 290:H794-H799, 2006.
  • Fruen, B.R., E.M. Balog, J. Schafer, F.R. Nitu, D.D., Thomas, and R.L. Cornea. Direct Detection of Calmodulin Tuning by Ryanodine Receptor Channel Targets Using a Ca2+-Sensitive Acrylodan-Labeled Calmodulin. Biochem. 44:278-284, 2005.
  • Balog, E.M., L.E. Norton, R.A. Bloomquist, R.L. Cornea, D.J. Black, C.F. Louis C.F., D.D. Thomas, and B.R. Fruen. Calmodulin oxidation and methionine to glutamine substitutions reveal methionine residues critical for functional interaction with RyR1. J. Biol. Chem. 278:15615-15621, 2003.
  • Fruen, B.R., D.J. Black, R.A. Bloomquist, J.M. Bardy, J.D. Johnson, C.F. Louis, and E.M. Balog. Regulation of the RyR1 and RyR2 Ca2+ release channel isoforms by Ca2+-insensitive mutants of calmodulin. Biochem. 42: 2740-2747, 2003.
  • Balog, E.M., N.H. Shomer, B.R. Fruen, and C.F. Louis. Divergent effects of the MHS Arg615→Cys mutation on the Ca2+ and Mg2+ dependence of RyR1. Biophys J. 81:2050-2058, 2001.
  • Balog, E.M. and R.H. Fitts. Effects of low intracellular pH and elevated extracellular Ca2+ on the charge movement currents of frog skeletal muscle. J. Appl. Physiol. 90: 228-234, 2001.
  • Balog, E.M., P.K. Kane, B.R. Fruen, and C.F. Louis. Mechanisms of inorganic phosphate regulation of the skeletal muscle SR Ca2+ release channel. Am. J. Physiol. Cell Physiol. 278:C601-C611, 2000.
  • Balog, E.M., N. Enzmann and E.M. Gallant. Fatigue in malignant hyperthermic and normal porcine skeletal muscle. Muscle Nerve 23:223-230, 2000.
  • Balog, E.M. and E.M. Gallant. Modulation of the sarcolemmal L-current by alterations in SR Ca2+ release. Am. J. Physiol. Cell Physiol. 276:C128-C135, 1999.
  • Lentz, L.L., S.J. Valberg, E.M. Balog, J.R. Mickelson, and E.M. Gallant. Abnormal regulation of muscle contraction in horses with recurrent exertional rhabdomyolysis. Am. J. Vet. Res. 60:992-999, 1999.
  • Thompson, J., E.M. Balog, R.H. Fitts and D.A. Riley. Five myofibrillar lesion types in eccentrically challenged, unloaded rat adductor longus muscle - a test model. Anat. Rec. 254: 39-52, 1999.
  • Enzmann, N., Balog, E.M., and E.M. Gallant. Effects of inhibition of sarcoplasmic reticulum Ca2+-ATPase on twitch fusion in malignant hyperthermic and normal porcine skeletal muscle. Muscle Nerve 21:361-366, 1998.
  • Balog, E.M. and R.H. Fitts. Alterations in intracellular sodium and potassium with fatiguing stimulation of skeletal muscle. J. Appl. Physiol. 81: 679-685, 1996.
  • Gallant, E. M., E. M. Balog, K. G. Beam. Slow calcium current is not reduced in malignant hyperthermic porcine myotubes. Muscle and Nerve, 19: 450-455, 1996.
  • Balog, E.M., L.V. Thompson, and R.H. Fitts. The role of sarcolemma action potentials and excitability in muscle fatigue. J. Appl. Physiol. 76:2157-2162, 1994.
  • Thompson, L.V., E.M. Balog, D.A. Riley, and R.H. Fitts. Muscle fatigue in the frog semitendinosus: Alterations in contractile function. Am. J. Physiol. Cell Physiol. 262:C1500-C1506, 1992.
  • Thompson, L.V., E.M. Balog, and R.H. Fitts. Muscle fatigue in the frog semitendinosus: The role of intracellular pH. Am. J. Physiol. Cell Physiol. 262:C1507-C1512, 1992.
  • Terracio. L., K. Rubin. D. Gulberg, E. Balog, W. Carver, R. Jyring, and T.K. Borg. Expression of collagen binding integrins during cardiac development and hypertrophy. Circ. Res. 68:734-744, 1991.