People

David . Warshaw, Ph.D.
David M. Warshaw, Ph.D.

Professor and Chair of Molecular Physiology & Biophysics

Office: HSRF 116    Phone: 802-656-4300    Email: David.Warshaw@med.uvm.edu

Myosin Molecular Motors
I received my B.S. in Electrical Engineering from Rutgers University and Ph.D. in Physiology & Biophysics from the University of Vermont. As a postdoc with Fredric Fay at UMass Medical, I studied single smooth muscle cell mechanics. My present research focuses on the structure and function of cardiac muscle contractile proteins as well as non-muscle molecular motors using single molecule biophysical techniques such as laser trapping and super-resolution microscopy. Presently, my lab has two research foci. One area focuses on the molecular mechanism by which myosin binding protein-C modulates cardiac and skeletal muscle contractility, using an in vitro muscle model systems. The other focus is in vitro 3D model systems of intracellular cargo transport by myosin motors. I have been the Principal Investigator of a National Institutes of Health (NIH) Program Project Grant focused on the molecular basis of genetic heart failure. I am an Established Investigator and Fellow of the American Heart Association and a Fellow of the Biophysical Society. I have organized numerous International Conferences and Symposia, including the Gordon Conference on “Muscle Contractile Proteins” (1999, 2002) and was the program co-chair of the 2009 Biophysical Society annual meeting. I have and continue to serve on numerous NIH review panels and was a member of the Scientific Advisory Panel for the NIH Nanomedicine Initiative. I have trained 26 pre- and postdoctoral fellows of which 17 have gone on to university faculty positions.

Guy M. Kennedy, Guy Kennedy

Research Engineer

Office: HSRF 115    Phone: 802-656-9420    Email: guy.kennedy@uvm.edu

My goal is to design, develop, fabricate and support world class microscopy systems for research in molecular physiology. Our research demands high sensitivity with fast temporal and precise spatial resolution. These systems include integrated Laser Optical Tweezers with dual color Total Internal Reflection Microscopy (TIRFM) along with single molecule detection, manipulation and tracking capabilities. Mechanical measurements of pico-newton force, nanometer displacement, and pico-newtons/ nanometer stiffness are used to address questions in single molecules. These techniques are applied to protein ensembles, intercellular dynamics, and molecular protein- protein interactions. High speed fluorescent imaging of single molecule dynamics are possible using state of the art ICCD cameras with TIR and far field illumination. Recent initiatives include high speed 3D tracking, STORM, and PALM Super Resolution microscopy. Myosin, Kinesin, C-Protein, Actin, Microtubules and other Cytoskeletal proteins are studied with our techniques.

Amy M. Li, Ph.D.Amy Li, Ph.D.

Postdoctoral Fellow

Office: HSRF 115    Phone: 802-656-3841    Email: Amy.Li@uvm.edu

Myosin Binding Protein C in Skeletal Muscle
Striated muscle expresses three isoforms of myosin binding protein C (MyBP-C) that are critical regulators of contractility. Cardiac MyBP-C behaves as a molecular break or gas-pedal under distinct physiological conditions, and disruptions to these processes leads to disease. While its role in cardiac muscle has been extensively investigated, our understanding of what MyBP-C does in skeletal muscle remains unclear. Of particular interest is the recent discovery that a sub-set of muscular dystrophy patients carry mutations in skeletal MyBP-C. My research aims to characterize the expression, localization and function of skeletal MyBP-C using a compliment of biochemical and biophysical approaches.

Andrew M. Lombardo, Andrew Lombardo

Graduate Student

Office: HSRF 115    Phone: 802-656-3820    Email: Andrew.Lombardo@uvm.edu

Myosin movement
Myosin V and VI are processive molecular motors which transport cargo along actin filaments in a hand-over-hand fashion. Movement of these motors on differing actin tracks has been an area of intense study as post translational modifications, myosin associating proteins, bundles of actin and branching actin have all been shown to alter the way in which myosin navigates its path. As a part of the larger goal of the Warshaw laboratory, I am looking to increase complexity in our in vitro experiments to more accurately portray the environment in which myosin moves within the living cell.

Shane M. Nelson, Ph.D.Shane Nelson, Ph.D.

Faculty Scientist

Office: HSRF 115    Phone: 802-656-3820    Email: Shane.Nelson@uvm.edu

Myosin V Vesicle Transport in COS-7 cells
My work focuses on Myosin Va (myoVa), which is an intracellular cargo transporter. Based on in vitro experiments, a single myoVa molecule could perform this function as it can move processively along actin tracks in a “hand-over-hand” fashion. However, this has yet to be demonstrated in vivo. The cellular context presents numerous challenges to myoVa processivity such as the dense cytoskeletal network, actin-binding proteins, and other motors that share cargo transport duties with myoVa. To study the in vivo motion and processivity of myoVa, I introduced quantum dot (Qdot) labeled myoVa molecules into cultured fibroblast (COS-7) cells by pinocytosis, and observed the motion of individual motor molecules by TIRF microscopy. I have shown that individual myoVa molecules undergo a random walk by making frequent turns onto intersecting actin filaments in the densely packed subplasmalemmal actin cortex. My current efforts are to begin to understand how myoVa is targeted to its cargo and how multiple motor molecules coordinate their activity to bring about effective cargo transport.

Samantha M. Previs, Samantha B. Previs

Research Technician

Office: HSRF 115    Phone: 802-656-3841    Email: samantha.beck@uvm.edu

I am involved in experiments looking at the function of myosin-binding protein C and its role in cardiac muscle contraction, insulin granule secretion, and myosin transport on actin networks. I also provide general laboratory support by preparing reagents and ordering needed supplies.