Danuta Szczesna-Cordary, Ph.D.
Professor of Molecular & Cellular Pharmacology
Rosenstiel Medical Sciences Building 6113
2012 – pres Professor of Molecular and Cellular Pharmacology (with tenure) University of Miami Miller School of Medicine
2011 – pres Director, Training Program in Cardiovascular Signaling
2006 – 2012 Associate Professor
2003 – 2006 Research Associate Professor
1997 – 2003 Research Assistant Professor
Honors and Awards
2010 – Award of Tenure
2010 – Appreciation of Services Award, Center for Scientific Review National Institutes of Health
2005 – Robert J. Boucek, MD Research Award FL/Puerto Rico Affiliate
2004 – Certificate of Appreciation, American Heart Association
2004 – The Alberta Heritage Foundation for Medical Research Travel Award
1989 – Distinguished Scientific Achievement Award Polish Academy of Sciences
2012 – pres NIH/NIAMS Skeletal Muscle and Exercise Physiology Study Section (SMEP), member
2005 – 2010 NIH/NHLBI Cardiac Contractility Hypertrophy and Failure (CCHF), member
2006 NSF, ad hoc reviewer
2004 – 2005 AHA Southern/Ohio Valley, panel reviewer
THE SZCZESNA-CORDARY LAB
Pictured in 1st row from left-right: Priya Muthu, PhD - Postdoctoral Associate, Ana I. Rojas, BS - Research Associate II, Danuta Szczesna-Cordary, PhD - PI, Devin Kepchia - MCP Rotation Student; 2nd row: Katarzyna Kazmierczak, PhD - Assistant Scientist, Wenrui Huang - 4th year PhD Student, Jingsheng Liang, MD - Associate Scientist, Chenching Yuan (Vicky) - MCP Rotation Student.
The major area of research in my laboratory is related to the Ca2+ regulation of striated (skeletal and cardiac) muscle contraction. In particular, we focus on the role of the myosin regulatory (RLC) and essential (ELC) light chains in force generation and the kinetics of myosin cross-bridges.
Figure 1. The myosin head (S1) derived from the atomic structure by Rayment et al., 1993 . The heavy chain is shown in green, red, and blue to highlight functional domains. The essential light chain and regulatory light chain function to support the myosin neck region and are colored in yellow ( ELC) and magenta ( RLC).
There are three major and functionally different domains in the myosin molecule: a motor domain, a lever arm domain - both located in the myosin head (S1) (Fig. 1), and a tail region (Rayment et al., 1993; Saraswat and Lowey, 1998; Waller et al., 1995; Xie et al., 1994) . The myosin motor domain contains a catalytic site, also called an ATP binding pocket, and an actin binding domain. A small converter domain links the myosin motor domain to the lever arm region (Fig. 1). The lever arm domain of muscle myosin is composed of a long helix containing two IQ motifs (IQxxxRGxxxR) that form the attachment sites for the ELC and the RLC (Dominguez et al., 1998; Houdusse et al., 1999; Rayment et al., 1993; Saraswat and Lowey, 1998; Xie et al., 1994) (Fig. 1). The physiological importance of these two myosin light chains has been recently highlighted by the discovery of genetic mutations shown to cause Familial Hypertrophic Cardiomyopathy (FHC) (Fig. 2).
Figure 2. The regulatory domain of scallop myosin
(1WDC) by Houdusse and Cohen, 1996 .
The heavy chain (MHC) is shown in blue, the essential
light chain (ELC) in yellow and the regulatory light chain
(RLC) in red. The FHC mutations in ELC and RLC are
indicated with arrows.
Cardiovascular diseases are the number one cause of mortality worldwide with heart failure being highly prevalent in most affluent parts of the world. There is an urgent need for a better understanding of the mechanisms underlying FHC that often leads to premature sudden cardiac death (SCD) . Our research addresses the mechanisms by which mutations in myosin regulatory light chain and essential light chain cause FHC and lead to SCD (Fig. 2).
Over the past 8 years our laboratory has been studying the functional consequences of several FHC RLC mutations (E22K, N47K and R58Q) expressed in transgenic mice (Fig. 3). Our recent results revealed new possible mechanisms by which the FHC-mutated RLC proteins may affect the contractile function of the mutated myocardium. One of the mechanisms is based on the hypothesis that in healthy muscle, the RLC functions as a temporary intracellular Ca2+-buffer working in parallel with the sarcoplasmic reticulum (SR) Ca2+ pump in sequestering Ca2+, thereby promoting muscle relaxation. We hypothesize that by changing the properties of the RLC Ca2+-Mg2+ binding site (Fig. 3), the FHC mutations can facilitate or inhibit this intracellular RLC function and result in increased or decreased kinetics of muscle relaxation. Another hypothesis pertains to the mutation controlled metal occupancy of the Ca2+-Mg2+ binding site of RLC and the mechanism by which Ca2+ or Mg2+ binding to RLC may influence the interaction of myosin with actin and tension generation.
During muscle contraction, the increase in Ca2+ concentration activates the Ca2+-calmodulin dependent myosin light chain kinase (MLCK) and leads to phosphorylation of the RLC (at serine 15). Our solution studies showed a link between the effect of the specific FHC mutation and RLC phosphorylation and implicated both events, the Ca2+ binding to the RLC and its MLCK-phosphorylation play a key role in the regulation of cardiac muscle contraction. Both of these processes, most likely, operate as adaptive and/or protective mechanisms to either attenuate the effect of the FHC mutations and/or improve performance of the working muscle. Based on our findings and those of others, we further hypothesize that an FHC induced pathological cardiac phenotype can be rescued by Ca2+-calmodulin activated MLCK phosphorylation of the RLC-mutated myocardium. The specific questions that we ask are:
Figure 3. The regulatory light chain of myosin derived from the atomic
structure of S1 (2MYS) by Rayment et al., 1993 . The Ca2+-binding loop is
shown in green. The sites of FHC mutations are pointed with arrows.
- Do FHC induced changes in the properties of the RLC Ca2+-Mg2+ binding site inhibit or facilitate the function of RLC as a temporary intracellular calcium buffer? Do FHC mutations shift the metal occupancy of the RLC Ca2+-Mg2+ binding site during muscle contraction?
- Is RLC phosphorylation by Ca2+-calmodulin ( CaM) activated myosin light chain kinase (MLCK) affected by FHC-linked RLC mutations? Can MLCK phosphorylation rescue a mutation induced pathological cardiac phenotype?
- Do FHC-associated mutations in RLC alter intermolecular interactions between RLC and myosin heavy chain (HC) and ultimately myosin and actin? Do these changes lead to myofilament disarray, cardiac hypertrophy and dysfunction of the mutated myocardium?
This area of our research is funded by 5R01HL071778-07 and 5R01HL090786-02.
This project focuses on two areas of research:
- The importance of the direct N-terminal interaction of the ventricular myosin ELC with actin during cardiac muscle contraction.
- The mechanisms by which FHC mutations in ELC alter the physiological properties of cardiac muscle.
Transgenic mice have been generated expressing various levels of a truncated ventricular ELC, lacking 43 amino acids from its N-terminus (ELC-D 43), to mimic the distribution of the ELC observed in fast skeletal muscle. As a result, the mouse cardiac muscle contains varying ratios of the long (endogenous) to short (transgenic) ELC forms. Our hypothesis is that increasing ratios of short transgenic ELC- D 43 to long endogenous ELC will result in a progressively weakened binding of myosin to actin, decreased force development and ultimately in compromised cardiac muscle performance. We are testing this hypothesis by measuring the actin-myosin interaction and force development at the single molecule level and in skinned and intact muscle fibers from transgenic ELC- D 43 mice.
In addition, we are studying the mechanisms by which FHC mutations in ELC alter the physiological properties of cardiac muscle. To date five mutations in the MYL3 gene that encodes the human ventricular ELC have been associated with FHC (E56G, A57G, E143K, M149V, R154H). Various mutation-specific phenotypes in humans including multiple cases of SCD at a young age have been observed. Transgenic mice expressing these FHC ELC mutations have been generated and the physiological consequences studied in skinned and intact muscle fibers in vitro and in vivo by echocardiography, MRI and hemodynamic methods. Our hypothesis is that FHC ELC mutations will affect the mechanical and enzymatic properties of myosin by altering the interaction of the ELC with the heavy chain of myosin and/or the interaction of the N-terminus of ELC with actin and consequently lead to a compromised interaction of myosin with actin in the mutated myocardium. The most profound changes are expected with those FHC mutations that result in poor prognosis and SCD in humans.
Co-Investigators at UM
Dr. Julian Borejdo, Univ. of North Texas
Our collaborative research is funded by NIH/NHLBI R01-090786
Dr. Greg Sawicki, Univ. of Saskatchewan
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Doroszko A, Polewicz D, Cadete VJ, Sawicka J, Jones M, Szczesna-Cordary D, Cheung PY, Sawicki G. (2010) Neonatal asphyxia induces the nitration of cardiac myosin light chain 2 (MLC2) which is associated with cardiac systolic dysfunction.Shock. 2010 Apr 6.
Greenberg, M.J., Watt, J.D., Jones, M., Kazmierczak, K., Szczesna-Cordary, D
., Moore, J.R. (2009) Regulatory light chain mutations associated with cardiomyopathy affect myosin mechanics and kinetics
. J. Mol. Cell. Cardiol. 46:108-115. Epub 2008 Sep 27.
Greenberg, M.J., Mealy, T.R., Watt, J.D., Jones, M., Szczesna-Cordary, D.,
Moore, J.R. (2009) The Molecular Effects of Skeletal Muscle Myosin Regulatory Light Chain Phosphorylation
. Am J Physiol Regul Integr Comp Physiol 297:R265-274
W. Kerrick G., Kazmierczak, K., Xu, Y., Wang, Y. and Szczesna-Cordary, D
. (2009) Malignant D166V-FHC mutation in the ventricular myosin regulatory light chain causes profound effects in skinned and intact papillary muscle fibers from transgenic mice
. FASEB J. 23: 855-865. Epub 2008 Nov 5. Szczesna-Cordary, D
., Jones, M., Moore, J.R., Watts, J., W. Kerrick G.L., Xu, Y., Wang, Y., Wagg, C., Lopaschuk G.D. (2007) Myosin Regulatory Light Chain E22K Mutation Results in Decreased Cardiac Intracellular Calcium and Force Transients
. FASEB. J. 21: 3974-3985.
Wang, Y., Szczesna-Cordary, D
., Craig, R., Perez-Diaz, Z., Guzman, G., Miller, T., Potter, J.D. (2007) Fast Skeletal Muscle Regulatory Light Chain Is Required For Fast and Slow Skeletal Muscle Development
. FASEB J. 21:2205-2214, 2007.
Olga M. Hernandez, Michelle Jones, Georgianna Guzman, and Danuta Szczesna-Cordary
. (2007) Myosin Essential Light Chain in Health and Disease
. Am J Physiol Heart Circ Physiol, 292(4):H1643-54
Wang, Y., Xu, Y., W. Kerrick, G., Wang, Y., Guzman, G., Diaz-Perez, Z., Szczesna-Cordary, D
. (2006) Prolonged Ca2+ and Force Transients in Myosin RLC Transgenic Mouse Fibers Expressing Malignant and Benign FHC Mutations
. Journal of Molecular Biology, Volume 361, Issue 2, 11 August 2006, Pages 286-299.
Dumka, D. Talent, J., Akopowa, I., Guzman, G., Szczesna-Cordary, D.
, Borejdo, J. (2006) E22K Mutation of RLC that Causes Familial Hypertrophic Cardiomyopathy in Heterozygous Mouse Myocardium: Effect on Cross-Bridge Kinetics
.Am J Physiol Heart Circ Physiol, Nov 2006; 291: H2098 - H2106.
Hernandez, O., Szczesna-Cordary, D
., Knollman, B.C., Miller, T., Bell, M., Zhao, J., Sirenko, S.G., Diaz, Z., Guzman, G., Xu. Y., Wang, Y., Kerrick, W.G., Potter, J.D. (2005) F110I and R278C Troponin T Mutations that Cause Familial Hypertrophic Cardiomyopathy Affect Muscle Contraction in Transgenic Mice and Reconstituted Human Cardiac Fibers
.J. Biol. Chem. 280: 37183-37194.
Sawicki, G., Leon, H, Sawicka, J., Sariahmetoglu, M., Szczesna-Cordary, D
., Schulz, R. (2005) Degradation of myosin light chain in isolated rat hearts subjected to ischemia-reperfusion injury: a new intracellular target for matrix metalloproteinase-2
.Circulation 112: 544-552.
., Jones, M., Zhao, J., Zhu, G., Stull, J.T. and Potter, J.D. (2002) Phosphorylation of the Regulatory Light Chains of Myosin Affects Ca2+ Sensitivity of Skeletal Muscle Contraction
. J. Applied Physiol.,92:1661-1670.
Miller, T., Szczesna, D
., Housmans, P.R., Zhao, J., de Freitas, F., Gomes, A.V., Culbreath, L., McCue, J., Wang, Y., Xu, Y., Kerrick, W.G. and Potter, J.D. (2001) Abnormal Contractile Function in Transgenic Mice Expressing an FHC-Linked Troponin T (I79N) Mutation
. J. Biol. Chem. 276, 3743-3755.
Ghosh, D., Li, Q., Gomes, A.V., Guzman, G., Arana, C., Zhi, G., Stull, J.T., Potter, J.D.(2001) Familial hypertrophic cardiomyopathy mutations in the regulatory light chains of myosin affect their structure, Ca2+ binding, and phosphorylation
. J. Biol. Chem. 276, 7086-7092.
Zhang, R., Zhao, J., Jones, M., Guzman, G and Potter, J.D. (2000) Altered Regulation of Cardiac Muscle Contraction by Troponin T Mutations that Cause Familial Hypertrophic Cardiomyopathy
. J. Biol. Chem. 275:624-630.
Parsons, B., Szczesna, D., Zhao, J., Van Slooten, G., Kerrick, W.G.L., Putkey, J.A. and Potter, J.D. (1997) The Effect of pH on the Ca2+ Affinity of the Ca2+ Regulatory Sites of Skeletal and Cardiac Troponin C in Skinned Muscle Fibers. J. Muscle Res. Cell Motility. 18, 599-609.
Szczesna, D., Guzman, G., Miller, T., Zhao, J., Farokhi, K., Ellemberger, H. and Potter,J.D. (1996) The Role of the Four Ca2+ Binding sites of Troponin C in the Regulation of Skeletal Muscle Contraction. J. Biol. Chem. 271:8381-8386.
Szczesna, D. and Fajer, P.G. (1995) The Tropomyosin Domain is Flexible and Disordered in Reconstituted Thin Filaments.Biochemistry 34:3614-3620.
Szczesna, D., Graceffa, P., Wang, C.-L.A. and Lehrer, S.S. (1994) Myosin S1 Changes the Orientation of Caldesmon on Actin.Biochemistry 33:6716-6720.
Szczesna, D. and Lehrer, S.S. (1993) The Binding of Fluorescent Phallotoxins to Actin in Myofibrils.J. Mus. Res. Cell Mot. 14:594-597.
Szczesna, D. and Lehrer, S.S. (1992) Linear Dichroism of Acrylodan-Labeled Tropomyosin and Myosin Subfragment 1 Bound to Actin in Myofibrils.Biophys. J. 61:993-1000.
Szczesna, D., Borovikov, Y.S., Kakol I. and Sobieszek, A. (1989) Interaction of Tropomyosin with Factin-Heavy Meromyosin Complex.Biol. Chem. Hoppe-Seyler 370:399-407.
Szczesna, D., Borovikov, Y.S., Lebedeva, N.N. and Kakol, I. (1987) Effect of Phosphorylation of Myosin Light Chains on Interaction of Heavy Meromyosin with Regulated F-Actin in Ghost Fibers.Experientia 43:194-196.
Szczesna, D., Sobieszek, A. and Kakol, I. (1987) Binding of Phosphorylated and Dephosphorylated Heavy Meromyosin to F-Actin.FEBS Letters 210(2):177-180.
Kakol, I., Borovikov, Y.S., Szczesna, D., Kirillina, V.P. and Levitski, D.I. (1987) Conformational Changes of F-Actin in Myosin-Free Ghost Single Fiber Induced by either Phosphorylated or Dephosphorylated Heavy Meromyosin.Biochim. Biophys. Acta 913:1-9.
Borovikov, Y.S., Kakol, I., Szczesna, D., Kirillina, V.P. and Levitski, D.I. (1986) Effect of Phosphorylation of Rabbit Skeletal Muscle MyosinLight Chains on the Nature of Conformational Changes of F-Actin Induced by Heavy Meromyosin.Biochimia (In Russian) 51(4):691-694.
Stepkowski, D., Szczesna, D., Wrotek, M. and Kakol, I. (1985) Factors Influencing Interaction of Phosphorylated and Dephosphorylated Myosin with Actin. Biochim. Biophys. Acta 831:321-329.
Stepkowski, D., Osinska, H., Szczesna, D., Wrotek, M. and Kakol, I. (1985) Decoration of Actin Filaments with Skeletal Muscle Heavy Meromyosin Containing either Phosphorylated or Dephosphorylated Regulatory Light Chains. Biochim. Biophys. Acta 830:337-340.