My laboratory is interested in the mechanisms that regulate contraction of smooth muscles. We use biophysical, structural, and kinetic techniques to study the structure and function of myosin and actin, the major contractile proteins. These studies are addressing the structural mechanisms that control the activity of myosin. Smooth muscle myosin is regulated by phosphorylation, resulting in large conformational changes. The inactive unphosphorylated state is self-inhibited by interaction of the myosin tail domain with the catalytic and regulatory domains. We are studying the structure of this inhibited state by photocross-linking, fluorescence quenching and polarization, electron paramagnetic resonance, phosphorescence anisotropy, mass spectrometry and crystallography. Self-inhibited myosin is in equilibrium with myosin filaments, which is the force-generating conformation.

We are interested in understanding the regulation of this equilibrium in the cell. Major approaches are measurements of contractile force in intact tissues, immunofluorescence microscopy of transiently-transfected cells, dynamic imaging of GFP- and other fluorescent constructs in live cells, mutagenesis, and fluorescence photo-bleaching recovery.

Medical Biochemistry 602

NIH grant in 17th year of continuous funding

Topographical Studies of Smooth and Nonmuscle Myosins

Co-PI for COBRE, Smooth Muscle Plasticity, University of Nevada School of Medicine

Member - American Heart Association Study Section (National Organization) - Cellular Cardiovascular Physiology and Pharmacology (1994-1997)

Member - American Heart Association Study Section -Washington/Oregon Affiliate (1995-1997)

Invited Participant - Roundtable Discussion on Future of Muscle Biology at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (Chaired by Dr. Stephen Katz, Director) (June 1996)

Member - Site Visit Team, Program Project Grant Review for Boston Biomedical Research Institute (NAIMS, The NIH) 1996

Co-Chair, Biophysical Society, Motility Subgroup (1997-98)

Co-chair, American Heart Association Study Section (National Organization) - Cellular Cardiovascular Physiology and Pharmacology (1997-8)

Co-chair, Great America Consortium Peer Review Committee, Cardiovascular Regulation, American Heart Association (1998-2000)

Member - American Heart Association Study Section, Molecular Biology of the Muscle (1999-2001)

Editorial Board Member, Journal of Biological Chemistry (2001-2006)

Member – National Institute of Arthritis and Musculoskeletal Disease, 2001 Site Visit Team, Program Project Grant Review for University of Vermont, Department of Molecular Physiology and Biophysics, College of Medicine, Myosin Dynamics during the Contractile Cycle

Member, National Heart Lung and Blood Institute (NHLBI), ad hoc reviewer (2000-2001).

Member, Special Study Section B, National Institutes of Health, 2001.

Bioinformatics Core Facility, University of Nevada, Reno; Advisory Board Member, Structural Bioinformatics (2002-2004)

Member, AHA Basic Cell Biology Study Section 1, 2002-2005

Ad hoc reviewer, Macromolecular Structure and Function C Study Section, National Institutes of Health, 2005

Member, AHA Basic Cell & Molecular Biology 1 Study Section 2006-present

Member, Editorial Board, Journal of Muscle Research and Cell Motility, 2006- present

Wahlstrom J, Randall A, Lawson D, Lyons D, Seims W, Crouch G J, Barr R, Facemyer KC, and Cremo CR. Structural Model of the Regulatory Domain of Smooth Muscle Heavy Meromyosin, J. Biol. Chem. 278, 5123-5131 (2003).

Ellison PA, DePew ZS and Cremo CR. Both Heads of Tissue-Derived Smooth Muscle Heavy Meromyosin Bind to Actin in the Presence of ADP, J. Biol. Chem. 278 4410-4415 (2003).

Perkins W J, Lorenz RR., Bogoger M., Warner DO, Cremo CR, and Jones KA. A Novel Mechanism by which Hydrogen Peroxide Decreases Calcium Sensitivity in Airway Smooth Muscle, American Journal of Physiology, Lung Cellular and Molecular Physiology, 284 L324-32 (2003).

Mazhari SM, Selser CT and Cremo CR. Novel sensors of the regulatory switch on the regulatory light chain of smooth muscle myosin, J. Biol. Chem. 279 39905-14 (2004).

Li, Hui-Chun, Song, Likai, Salzameda, B., Cremo, C. R. and Fajer, P. G. (2006) Regulatory and Catalytic Domain Dynamics of Smooth Muscle Myosin Filaments, Biochemistry 45 (19), 6212-6221.

Salzameda, B., Beck, B. W., Facemyer, K. C., and Cremo, C.R. (2006) The N-terminal lobes of both regulatory light chains interact with the tail domain of smooth muscle myosin in the 10S conformation, accepted to J. Biol. Chem. In press online.