Curriculum Vitae. MARION J. SIEGMAN, Ph.D. [July 2014]

Curriculum Vitae MARION J. SIEGMAN, Ph.D. [July 2014] Office Address: Place of Birth: Department of Molecular Physiology & Biophysics Jefferson Medical College 1020 Locust Street Philadelphia, PA 19107 (215) 503-3975 Email: marion.siegman@jefferson.edu Brooklyn, New York Education: Secondary: College: Graduate: Midwood High School Brooklyn, New York Newcomb College, Tulane University New Orleans, Louisiana B.A. Biology, 1954 State University of New York, Downstate Medical Center Brooklyn, New York Ph.D.: Pharmacology, 1966 Professional Experience: 1/55-9/57 Research Assistant; Rockefeller Institute for Medical Research, New York (Laboratory of Paul A. Weiss) 1/58-8/59 Research Assistant; State University of New York, Downstate Medical Center, Brooklyn, New York, Department of Pharmacology (Lab of L. Procita) 8/59-7/60 Electron Microscopist; Karolinska Institute, Nobel Institute for Cell Research and Genetics, Stockholm, Sweden (Lab of T. Caspersson) 9/60-9/61 Research Assistant; State University of New York, Downstate Medical Center, Brooklyn, New York, Department of Pharmacology (Lab of C.Y. Kao) 9/61-6/66 Graduate Student and Teaching Assistant; State University of New York, Downstate Medical Center, Brooklyn, New York, Department of Pharmacology (Robert F. Furchgott, Chair) 6/66-8/67 Research Associate (Post-Doctoral) State University of New York, Downstate Medical Center, Brooklyn, N. Y., Department of Pharmacology (Lab of CY.Kao) 9/67-6/68 Instructor, Jefferson Medical College, Department of Physiology, Philadelphia, Pennsylvania 7/68-6/71 Assistant Professor, Jefferson Medical College, Department of Physiology, Philadelphia, Pennsylvania 7/71-6/77 Associate Professor, Jefferson Medical College, Department of Physiology, Philadelphia, Pennsylvania 7/77 - Professor, Jefferson Medical College, Department of Physiology, Philadelphia, Pennsylvania 7/01-6/02 Acting Chair, Department of Physiology, Jefferson Medical College 7/02 - Chair, Department of Physiology, Jefferson Medical College 1

Special Activities and Honors: Burlington-Northern Foundation Award, for Excellence in Teaching and Productivity in Research, Jefferson Medical College, 1986 Christian R. and Mary Lindback Award for Excellence in Teaching, Jefferson Medical College, 1987 Kappa Beta Phi of Jefferson Medical College Faculty Award for Excellence in Medical Education, 1989 Outstanding Alumna Award, Newcomb College, Tulane University, 1990 Honorary Life Member, Alumni Association College of Graduate Studies, Thomas Jefferson University, 1997 Honorary Life Member, Alumni Association of Jefferson Medical College, Thomas Jefferson University, 1998 Dean s Award for Teaching Excellence, Jefferson Medical College, 2000 Portrait of Marion J. Siegman presented to Jefferson Medical College and Thomas Jefferson University by Graduating Class of 2001 of Jefferson Medical College and Colleagues, March 2001 Member, Jefferson Academy of Distinguished Educators 2010- present Professional Societies Membership: Offices Held: Committees: Other: American Physiological Society Biophysical Society Physiological Society of Philadelphia Sigma Xi Society of General Physiologists Society for Experimental Biology and Medicine International Society for Myochemistry President, Sigma Xi, Jefferson Medical College Chapter President, Physiological Society of Philadelphia Treasurer, Physiological Society of Philadelphia Councillor, Physiological Society of Philadelphia Chairperson, Myo-Bio Group, American Physiological Society Program Committee, Muscle Physiology, American Physiological Society (1982-1988) Education Committee of the American Physiological Society (1982-1988) Chairperson, Section Advisory Committee, American Physiological Society (1984-1987) Archivist, IUPS 2010- present Peer Review Panels: Ad Hoc Member, Physiology Study Section, National Institutes of Health, June 1978 Member, Advisory Committee for Physiology, Cellular and Molecular Biology, National Science Foundation, August 1978 - July 1979 Member, Physiology Study Section, National Institutes of Health, July 1979 - June 1983 Ad Hoc Reviewer, Physiology Study Section, National Institutes of Health, June 1985 Ad Hoc Reviewer, Experimental Cardiovascular Sciences Study Section, National Institutes of Health, October 1986 Ad Hoc Reviewer, Special Study Sections for NIHLBI for RFA and Program Project Applications 1992-2005 Reviewer, American Heart Association, Southeastern Pennsylvania Chapter, 1986-1987 Reviewer, National American Heart Association, 1987-1989 Editorial Board, American Journal of Physiology, Cell & General Physiology Section, 1984-1987 Editorial Board, Advances in Physiology Education, American Physiological Society, 1988-1993 2

Publication Reviewer (past 5 years): Advances in Physiology Education American Journal of Physiology Circulation Research Comparative Biology and Physiology Journal of Applied Physiology Journal of Experimental Biology Pflugers Archiv European Journal of Physiology Proceedings of the National Academy of Science Nature Cell Biology FASEB Journal Research Support and Awards: Cation Transport and Metabolism in Myometrium; NIH, 1968-1971 Extracellular Space of Vascular Smooth Muscle, GRS, 1968-1969 Travel Award, XXV International Congress of Physiological Sciences, Munich 1971; National Research Council Contraction of Intestinal and Uterine Smooth Muscle; NIH, 1974-1977 Contraction of Pulmonary Vascular Smooth Muscle, NIH, 1978-1984 Research on Vascular Smooth Muscle, SmithKline, 1983-1987 Conference on Contraction of Smooth Muscle, NIH, 1986 Contraction and Energetics of Visceral and Vascular Smooth Muscle, NIH, Program Project to Pennsylvania Muscle Institute, 1973-1993 Functional Adaptations of Intestinal Smooth Muscle, NIH, 1988-1994 Regulation of Energy Transduction in Smooth Muscle (Co-PI with T.M. Butler), 1994-1999 Catch: Mechanochemistry and Regulation in Smooth Muscle 1994-2005 Catch: Mechanochemistry and Regulation in Smooth Muscle 2005-2010 (Thomas Butler, P.I., M.J. Siegman, Co-PI) Dynamic Limits on Contraction of GI Smooth Muscle NIH 2010-2014 Invited Participation in National and International Symposia: Chairperson, Session on Smooth Muscle Mechanics, Gordon Conference on Smooth Muscle, Holderness, N.H., 1973 Speaker, Gordon Conference on Smooth Muscle, Holderness, N.H., 1973; "Analysis of Contraction and the Active State in Smooth Muscle" Speaker, J. Earl Thomas Memorial Symposium on "Functions of the Stomach and Intestine," Philadelphia, PA 1973; "Current Concepts of the Contractile Process in Smooth Muscle." Speaker, Satellite Symposium on "Excitation-Contraction Coupling in Smooth Muscle," Heidelberg, 1977; "Mechanical and Energetic Correlates of Relaxation in Mammalian Smooth Muscle" Chairperson, Session on Muscle Mechanics, Symposium on "Physiology of Smooth Muscle,: American Gastroenterology Society, Hyannis, MA, 1977 Speaker, Symposium on "Physiology of Smooth Muscle," American Gastroenterology Society, Hyannis, MA, 1977; "Viscoelastic Properties of Resting Smooth Muscle" and "Studies on the Energetics of Contraction in Smooth Muscle" Speaker, International Symposium on "Smooth Muscle Contraction: Winnipeg, Canada, 1981; "Energetic, Mechanical and Structural Correlates of the Length-Tension Relationship in Smooth Muscle" Co-Chairperson, Session on Muscle Energetics, Symposium on "Basic Biology of Muscles: A Comparative Approach," Society of General Physiologists, Woods Hole, MA, 1981 Speaker, Symposium on "Basic Biology of Muscles: A Comparative Approach," Woods Hole, MA, 1981; "The Length-Tension Relationship in Smooth Muscle: Energetics, 3

Mechanics and Ultrastructure" Speaker, FASEB "Summer Research Conference on Smooth Muscle," Saxton's River, VT, 1982; "Myosin Light Chain Phosphorylation, Energetics and Mechanical State in Mammalian Smooth Muscle" Chairperson and Speaker, I.U.P.S. Satellite Symposium on "Bronchial Smooth Muscle," Bowral, Australia, 1983; "Mechanical Properties and Chemical Composition of Intrapulmonary Vascular Smooth Muscle" Speaker, IUPS Satellite Symposium on "Smooth Muscle", Hayman Island, Australia, 1983; "Energetics and Mechanical State of Smooth Muscle" Speaker, Workshop on "Airway Smooth Muscle," National Institutes of Health, 1983; "Cellular Control of Crossbridge States in Smooth Muscle" Speaker, 2nd International Conference on Muscle Energetics, Burlington, VT, 1984; "Regulation of Crossbridge Cycling and Energetics in Mammalian Smooth Muscle" Chairperson and Speaker, Session on "Muscle Energetics", 50th Jubilee of the Hungarian Physiological Society, Budapest, Hungary, 1985 Speaker, Symposium on "Protein Phosphatases: Roles of Phosphorylation-Dephosphorylation in Cardiac and Vascular Smooth Muscle," Belgian Royal Academy of Medicine, Brussels, Belgium, 1985 Speaker, State-of-the-Art Lecture on "Chemical Energetics and Regulation of Crossbridge Cycling During Contraction of Mammalian Smooth Muscle,: 10th International Symposium on Gastrointestinal Motility, Mayo Foundation, 1986 Speaker, Workshop on "Calcium Regulation in Smooth Muscle," Austrian Academy of Sciences, Salzburg, Austria, 1986 Speaker and Organizer, I.U.P.S. Satellite Conference on "Contraction and Regulation of Smooth Muscle Contraction, Minaki, Ontario, Canada, 1986 Speaker, III International Conference on Muscle Energetics, "Effect of Okadaic Acid on the Relationships among Force, Myosin Light Chain Phosphorylation and ATPase Activity in Skinned Portal Vein, Yufuin, Japan, 1988 Speaker, II International Conference on Protein Phosphatases, "Effects of the Phosphatase Inhibitor Okadaic Acid on the Energetics and Regulation of Smooth Muscle", Univ. of Cincinnati, 1989 Chairperson and Speaker, "Energetics as an Approach to the Study of Smooth Muscle Contraction: the Bozler Legacy", Emil Bozler International Symposium "Frontiers in Smooth Muscle Research", Ohio State Univ. 1989 Speaker, International Symposium on Smooth Muscle, "Cooperative Mechanisms in the Regulation of Smooth Muscle Contraction," Fukuoka, Japan, 1991 Speaker, State-of-the-Art Lecture " The Economy of Smooth Muscle Contraction: Its Basis and Regulation", American Motility Society, Wintergreen, Virginia, October, 1994 Chairperson, Session on "Calcium Sensitivity Modulation of Smooth Muscle", International Congress on Calcium Sensitivity Modulation of Myofilaments in Cardiac and Smooth Muscle, Heidelberg, Germany, 1995 Speaker, "Cooperativity and the Regulation of Contraction in Smooth Muscle," Workshop on Smooth Muscle and Asthma, McGill University, May, 1996 Speaker, "New Insights on the Basis of Economy of Smooth Muscle", FASEB Conference on Smooth Muscle, Copper Mountain, Colorado, June, 1997 Speaker, "Catch and its Regulation", Symposium on "Catch and Its Control: New Insights into an Old Question", University of Tokyo, March 1998 Speaker, "Catch: The Ultimate Control of Calcium Sensitivity in Smooth Muscle", FASEB Conference on Smooth Muscle, Snowmass Village, July 2000 Speaker, Economics of Force Maintenance in Smooth Muscle: lessons learned from a mussel muscle, I International Conference on Muscle Energetics, University of Vermont, 2001 Speaker, Catch: the ultimate economy of force maintenance in smooth muscle, University of Indiana, April, 2002 Speaker, Force maintenance in smooth muscle: lessons on economy from a mussel muscle, Symposium on The Crossbridge Cycle in Smooth Muscle, University of Virginia, April, 2004 Speaker, "Twitchin phosphorylation regulates the crossbridge cycle in catch." European Muscle 4

Conference, Elba, Italy, September 2004. Speaker, 5th International Conference on Muscle Energetics, Vancouver, B.C. 2006 Speaker, "Twitchin: a catch-maintaining link in invertebrate smooth muscle", European Muscle Conference, Stockholm, Sweden, September 2007. Speaker, "Force maintenance by twitchin: a mini-titin that tethers thick and thin filaments in cacth. Regulatory CIrcuits in Cell Motility, Philadelphia, PA.,October 2013, Educational Activities: Symposia Organized at Jefferson Medical College: "Current Concepts of Cardiac Muscle Function" Physiological Society of Philadelphia, 1971 "Physiological Functions of Calcium" Physiological Society of Philadelphia, 1971 "Special Topics in Neurophysiology" College of Graduate Studies, Thomas Jefferson University 1973 "Current Concepts of the Contractile Process" College of Graduate Studies, Thomas Jefferson University, 1974 "Regulation of Force Output and Crossbridge Cycling in Smooth Muscle: Current Concepts", Physiological Society of Philadelphia, 1987 Chairperson, Sigma XI Student Research Day, 1987, 1988 Advances in Ion Channel Physiology, 2010 Regulatory Circuits in Cell Motility, 2013 International Symposia Organized: International Union of Physiological Sciences Satellite Symposium on "Contraction and Regulation of Smooth Muscle Contraction," Ontario, Canada 1986 Medical College Lectures: Medical Physiology Course for 1st year students: Autonomic Nervous System, Contractile Process of Striated Muscle and Smooth Muscle, Electrophysiology of Nerves and Muscles, Synaptic Transmission Molecular and Cellular Basis of Medicine for 1st year students: Electrophysiology of Nerves and Muscles, Synaptic Transmission Graduate Courses: Physiology of the Contractile Process Special Topics in Motility Fundamentals of Integrative Physiology Graduate College (current): Member, Graduate Faculty University Committees: Educational Advisory Committee Student Affairs member and Chairperson (6 years) Women's Liaison Committee Taskforce for AAMC Women's Liaison Officer Jefferson Medical College for the AAMC Faculty Representative to the Executive Council (elected) Student Promotions Curriculum Task Force for the Revision of the Basic Science Curriculum Professorial Faculty Advisory (elected) Faculty Appointments and Promotions Faculty Affairs Departmental Review Commons Board Advisory Committee for Minority Affairs Search Committee for the Chairperson of Medicine Search Committee for Dean of Graduate Studies and Research Administration 5

Search Committee for President of Thomas Jefferson University Executive Committee, Jefferson Academy for Distinguished Educators Student Committees, Medical College: Faculty Advisor, 1961 Society Faculty Advisor, Sophomore Sequelae Other Activities: Delegate to the People's Republic of China for Leaders of National Organizations, 1979 Visiting Investigator, Universite Pierre et Marie Curie, Station Zoologique, Villefrance-sur-Mer, France, 1982 PUBLICATIONS (Selected) Gordon, A., and M.J. Siegman. Mechanical properties of smooth muscle: I. Length-tension and forcevelocity relations. Am. J. Physiol. 221: 1243-1249, 1971. Gordon, A., and M.J. Siegman. Mechanical Properties of smooth muscle: II. Active state. Am. J. Physiol. 221: 1250-1254, 1971. Siegman, M.J., and A. Gordon. Potentiation of contraction: effect of calcium and caffeine on the active state. Am. J. Physiol. 222: 1587-1593, 1972. Siegman, M.J., T.M. Butler, S.U. Mooers, and R.E. Davies. Crossbridge attachment, resistance to stretch and viscoelasticity in resting mammalian smooth muscle. Science 191: 383-385, 1976. Butler, T.M., M.J. Siegman, and R.E. Davies. Rigor and resistance to stretch in vertebrate smooth muscle. Am. J. Physiol. 231: 1509-1514, 1976. Siegman, M.J., T.M. Butler, S.U. Mooers, and R.E. Davies. Calcium dependent resistance to stretch and stress relaxation in resting smooth muscles. Am. J. Physiol. 231: 1501-1508, 1976. Siegman, M.J., T.M. Butler, S.U. Mooers, and R.E. Davies. Mechanical and energetic correlates of isometric relaxation in mammalian smooth muscle. In: Excitation-Contraction Coupling in Smooth Muscle. Edited by: R. Casteels, T. Godfraind, and J.C. Ruegg. Elsevier North Holland, Amsterdam, 1977, pp. 449-453. Butler, T.M., M.J. Siegman, S.U. Mooers, and R.E. Davies. High energy phosphate utilization during force development and force maintenance in mammalian smooth muscle. Ibid: pp. 463-469. Butler, T.M., M.J. Siegman, S.U. Mooers, and R.E. Davies. The chemical energetics of single isometric tetani in mammalian smooth muscle. Am. J. Physiol. 235: C1-C7, 1978. Siegman, M.J., T.M. Butler, S.U. Mooers, and R.E. Davies. Chemical energetics of force development, force maintenance and relaxation in mammalian smooth muscle. J. Gen. Physiol. 76: 609-629, 1980. Butler, T.M., and M.J. Siegman. Chemical energetics of contraction in mammalian smooth muscle. Fed. Proc. 41: 204-208, 1982. Butler, T.M., M.J. Siegman, and S.U. Mooers. Chemical energetics of contraction in mammalian smooth muscle. In: Basic Biology of Muscle: A Comparative Approach. Edited by: B.M. Twarog, R.J.C. Levine, and M.M. Dewey. Raven Press, New York, 1982, pp.189-201. Butler, T.M., and M.J. Siegman. Chemical energy usage and myosin light chain phosphorylation in mammalian smooth muscle. Fed. Proc. 42: 57-61, 1983. Butler, T.M., M.J. Siegman, and S.U. Mooers. Chemical energy usage during shortening and work production in mammalian smooth muscle. Am. J. Physiol. 244: C234-C242, 1983. Butler, T.M., M.J. Siegman, S.U. Mooers, and R.J. Barsotti. Myosin light chain phosphorylation does not modulate crossbridge cycling rate in mammalian skeletal muscle. Science 220: 1167-1169, 1983. Siegman, M.J., T.M. Butler, and S.U. Mooers. Energetic, mechanical and ultrastructural correlates of the length-tension relationship in smooth muscle. In: Smooth Muscle Contraction. Ed. by N.L. Stephens, Marcel Dekker, NY, 1984, pp. 189-198. Siegman, M.J., T.M. Butler, S.U. Mooers, and A. Michalek. Ca ++ can affect Vmax without changes in myosin light chain phosphorylation in smooth muscle. Pflugers Arch. 401: 385-390, 1984. Butler, T.M., M.J. Siegman, and S.U. Mooers. Chemical energy usage during stimulation and stretch of mammalian smooth muscle. Pflugers Arch. 401: 391-395, 1984. Butler, T.M., and M.J. Siegman. High energy phosphate metabolism in vascular smooth muscle. Ann. Rev. Physiol. 47: 629-643, 1985. Siegman, M.J., T.M. Butler, and S.U. Mooers. Energetics and regulation of crossbridge states in 6

mammalian smooth muscle. Experientia 41: 1020-1025, 1985. Butler, T.M., M.J. Siegman, and S.U. Mooers. Changes in rate of crossbridge cycling during consecutive tetani in mammalian smooth muscle. Advances in Protein Phosphatases 2: 291-298, 1985. Butler, T.M., M.J. Siegman, and S.U. Mooers. Slowing of crossbridge cycling in smooth muscle without evidence of an internal load. Am. J. Physiol. 251: C945-C950, 1986. Butler, T.M., D.S. Pacifico, and M.J. Siegman. ADP release from myosin in permeabilized smooth muscle. Am. J. Physiol. 256: C59-C66, 1989. Siegman, M.J., T.M. Butler, and S.U. Mooers. Effect of the phosphatase inhibitor okadaic acid on the energetics and regulation of smooth muscle. Advances in Protein Phosphatases 5: 233-238, 1989. Siegman, M.J., T.M. Butler, and S.U. Mooers. Phosphatase inhibition with okadaic acid does not alter the relationship between force and myosin light chain phosphorylation in permeabilized smooth muscle. Biochem. Biophys. Res. Commun. 161: 838-842, 1989. Siegman, M.J., T.M. Butler, and S.U. Mooers. Energetics as an approach to the study of smooth muscle: The Bozler Legacy. In: Frontiers in Smooth Muscle Research. Edited by N. Sperelakis and J.D. Wood. Wiley-Liss, New York, 1990, pp.17-27. Butler, T.M., M.J. Siegman, S.U. Mooers, and S.R. Narayan. The myosin product complex during relaxation and in the resting state of smooth muscle. Am. J. Physiol. 258: C1092-C1099, 1990. Siegman, M.J., T.M. Butler, T. Vyas, S.U. Mooers, and S.R. Narayan. Cooperative mechanisms in the regulation of smooth muscle contraction. Adv. Exptl. Med. Biol. 304: 77-84, 1991. Siegman, M.J., T.B. Vyas, S.U. Mooers, and T.M. Butler. Energetics and regulation of smooth muscle contraction. Japanese J. Pharmacol. 58 (Suppl. II): 75P-80P, 1991. Vyas, T.B., S.U. Mooers, S.R. Narayan, J.C. Witherell, M.J. Siegman, and T.M. Butler. Cooperative activation of myosin by light chain phosphorylation in permeabilized smooth muscle. Am. J. Physiol. 263: C210-C219, 1992. Liddell, R.A., S.U. Mooers, M.J. Siegman and K.M. McHugh. Altered isoactin gene expression in the affected bowel segments of the lethal spotted mouse. Gastroenterology 105: 441-448, 1993. Trinkle-Mulcahy, L., M.J. Siegman and T.M. Butler. Metabolic characteristics of -toxin permeabilized smooth muscle. Am. J. Physiol. 266: C1673-C1683, 1994. Vyas, T.B., S.U. Mooers, S.R. Narayan, M.J. Siegman and T.M. Butler. Crossbridge cycling at rest and during activation: turnover of myosin-bound ADP in permeabilized smooth muscle. J. Biol. Chem. 269: 7316-7322, 1994. Butler, T.M., S.R. Narayan, S.U. Mooers and M.J. Siegman Rapid turnover of myosin light chain phosphate during crossbridge cycling in smooth muscle. Am. J. Physiol. 267: C1160-C1166, 1994 Trinkle-Mulcahy, L., K. Ichikawa, D.J. Hartshorne, M.J. Siegman and T.M. Butler. Thiophosphorylation of the130 kda subunit is associated with a decreased activity of myosin light chain phosphatase in -toxin permeabilized smooth muscle. J. Biol. Chem. 270: 18191-18194, 1995. Siegman, M.J., S.U. Mooers, T.B. Warren, D.M. Warshaw, M. Ikebe and T.M. Butler. Comparison of the effects of 2,3-butanedione monoxime on force production, myosin light chain phosphorylation and chemical energy usage in intact and permeabilized smooth and skeletal muscle. J. Muscle Research and Cell Motil. 15: 457-472, 1994 Siegman, M.J., L. Trinkle-Mulcahy, S.U. Mooers, S.R. Narayan and T.M. Butler. Myosin light chain phosphorylation and mechanical control of crossbridge kinetics in smooth muscle. Proceedings of the International Congress on Calcium Sensitivity Modulation of Myofilaments in Cardiac and Smooth Muscle 69, 1995. Siegman, M.J.,T.M. Butler, S.U. Mooers, L.Trinkle-Mulcahy, S. Narayan, W.S. Stirewalt and B. C. Starcher. Hypertrophy of Colonic Smooth Muscle: Structural Remodeling, Chemical Composition and Force Output. Am. J. Physiol. 272: G1560-1570, 1997 Siegman, M.J., T.M. Butler, S.U. Mooers, L. Trinkle-Mulcahy, S. Narayan, L. Adam, S. Chacko, H. Haase and I. Morano. Hypertrophy of Colonic Smooth Muscle: Contractile Proteins, Shortening Velocity and Regulation. Am. J. Physiol. 272: 1571-1580, 1997. Siegman, M.J., S.U. Mooers, C. Li, S. Narayan, L. Trinkle-Mulcahy, S. Watabe, D.J. Hartshorne and T.M. Butler. Phosphorylation of a High Molecular Weight (~600 kda) Protein Regulates Catch in Invertebrate Smooth Muscle. J. Muscle Research and Cell Motility 18: 655-670, 1997. Siegman, M.J., Daisuke Funabara, Shigeharu Kinoshita, Shugo Watabe, David J. Hartshorne and Thomas M. Butler. Phosphorylation of a twitchin-related protein controls catch and calcium- 7

sensitivity of force production in invertebrate smooth muscle. Proc. Natl. Acad. Sci., 95:5383-5388, 1998. Butler, T.M., S.U. Mooers, Chenqing Li, S. Narayan, and M.J. Siegman. Regulation of catch muscle by Twitchin phosphorylation: Effects on force, ATPase, and shortening. Biophysical Journal 75: 1904-1914, 1998. Butler, T.M., S.R. Narayan, S.U. Mooers, D.J. Hartshorne and M.J. Siegman. The myosin cross-bridge cycle and its control by twitchin phosphorylation in catch muscle. Biophysical Journal 80:415-426, 2001 Funabara, D., S.Kinoshita, S.Watabe, M.J.Siegman, T.M.Butler, and D.J.Hartshorne. Phosphorylation of Molluscan Twitchin by the camp-dependent Protein Kinase. Biochemistry 40:2087-2095, 2001. Funabara, D., S. Watabe, S.U. Mooers, S. Narayan, C. Dudas, D.J. Hartshorne, M.J. Siegman, and T.M.Butler. Twitchin from molluscan catch muscle: Primary structure and relationship between sitespecific phosphorylation and mechanical function. J. Biol. Chem. 278:29308-29316, 2003 Funabara, Daisuke, Satoshi Kanoh, Marion J. Siegman, Thomas M. Butler, David J. Hartshorne and Shugo Watabe. Twitchin as a regulator of catch contraction in molluscan smooth muscle. J. Muscle Res and Cell Motil: 2005 Butler, Thomas M., Susan U. Mooers and Marion J. Siegman. Catch force links and the low to high force transition of myosin. Biophys. J. 90: 3193-3202, 2006 Siegman, M.J., Franke, A.S., Mooers, S.U., Narayan, S.R., and Butler, T.M. Twitchin: a catch-maintaining link in invertebrate smooth muscle. J. Muscle Research & Cell Motility 28: 429-432, 2007 Franke, A.S., Mooers, S.U. Narayan, S.R., Siegman, M.J. and Butler, T.M. Myosin crossbridge kinetics and the mechanism of catch. Biophys J. 93: 554-565, 2007 Butler,T.M. and Siegman, M.J. Mechanism of Catch Force: Tethering of Thick and Thin Filaments by Twitchin. J Biochemistry and Biotechnology, May 2010 Article ID 725207 ; http://www.hindawi.com/journals/jbb/2010/725207.html (invited review). Butler,T.M., Mooers,S.U., Narayan,S.R., and Siegman,M.J. (2010). The N-terminal region of twitchin binds thick and thin contractile filaments: redundant mechanisms of catch force maintenance. J. Biol. Chem. 285, 40654-40665 Butler, T.M. and M.J. Siegman. A force-activated kinase in a catch smooth muscle (2011). J. Muscle Res. Cell Motility, 2011 Mar;31(5-6):349-58. Epub 2011 Feb 1. Somlyo, A.V. and M.J. Siegman. Smooth Muscle Myocyte Ultrastructure and Contractility. In Muscle: Fundamental Biology and Mechanisms of Disease, Elsevier, 2012 Siegman, M.J., Davidheiser, S., Mooers, S.U. and Butler, T.M., 2012. Structural limits on force production and shortening in smooth muscle. J. Muscle Research and Cell Motility 34: 43-60, 2012. Siegman, M.J., Force transmission in the rat anococcygeus muscle: a tale of two tendons. Anatomical Record, 2014, in press. 8