James Spudich (Stanford) 3: Ca2+ regulation of muscle contraction

https://www.ibiology.org/cell-biology...

James Spudich begins his talk with an early history of muscle biology, and through parts 2-4 of his talk, he moves forward to our current understanding of the molecular basis of muscle contraction and disease.

Talk Overview:
In his third talk, Spudich recounts his first foray into muscle research as a postdoctoral fellow. He was interested in understanding how Ca2+ regulates muscle contraction by binding to the troponin/tropomyosin complex.  Using electron micrographs and X-ray diffraction, Spudich showed that tropomyosin, which forms a long filament, lies along actin filaments and blocks the myosin binding sites on actin.  When muscle is stimulated to contract, Ca2+ is released from intracellular stores and binds to troponin.  The binding of Ca2+ to troponin causes the tropomyosin molecules to move, allowing myosin to bind to actin, and the muscle to contract.  While explaining these experiments, Spudich gives a very nice explanation of how a diffraction pattern is obtained and how to think about real and reciprocal space. More recent improvements in X-ray beam strength and electron microscopy, have confirmed this model and filled in more details.

Speaker Biography:
James (Jim) Spudich is the Douglass M. and Nola Leishman Professor of Cardiovascular Disease in the Department of Biochemistry at Stanford University School of Medicine.  For the past several decades, his lab has studied the structure and function of the myosin family of motor proteins.  More recently Spudich’s lab has focused on human cardiac muscle myosin and the molecular basis of hypertrophic cardiomyopathy.  

Spudich received his B.S. in chemistry from the University of Illinois and his Ph.D. in biochemistry from Stanford University. He was a post-doctoral fellow at Stanford University and then at the MRC Laboratory in Cambridge where he worked with Hugh Huxley.  Spudich joined the faculty of the University of California, San Francisco from 1971-1977.  In 1977, he moved to Stanford University where he was first a professor in the Department of Structural Biology and, since 1992, has been a professor in the Department of Biochemistry.  Spudich is also an Adjunct Professor at the Institute of Stem Cell Biology and Regenerative Medicine (inStem) and the National Center for Biological Sciences (NCBS) in Bangalore, India.

Spudich serves on numerous editorial and scientific advisory boards.  His research contributions have been recognized with many honors and prizes including the Albert Lasker Basic Medical Research Award in 2012, the E.B. Wilson Award from the American Society for Cell Biology in 2011, and the Biophysics Society Award for Outstanding Investigator in 2005.  He is an elected fellow of the American Association for the Advancement of Science and the American Academy of Arts and Sciences, and an elected member of the US National Academy of Sciences.

Learn more about Spudich’s research here: http://spudlab.stanford.edu/