By Ron Vale (HHMI/University of San Fransisco )
Last week we discussed how actin uses energy from polymerization to bias random thermal motion and produce directed motility. Transposing this idea to a kinesin motor on a microtubule track: how could it use energy from ATP hydrolysis to bias random thermal motion to produce directed motility?
Molecular Motor Proteins
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The Mechanisms of Dynein Motility
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Molecular motor proteins are fascinating enzymes that power much of the movement performed by living organisms. In the first part of this lecture, I will provide an overview of the motors that move along cytoskeletal tracks (kinesin and dynein which move along microtubules and myosin which moves along actin). The main focus of this lecture is on how motor proteins work. How does a nanoscale protein convert energy from ATP hydrolysis into unidirectional motion and force production? What tools do we have at our disposal to study them? The first part of the lecture will focus on these questions for kinesin (a microtubule-based motor) and myosin (an actin-based motor), since they have been the subject of extensive studies and good models for their mechanisms have emerged. I conclude by discussing the importance of understanding motor proteins for human disease, in particular illustrating a recent biotechnology effort from Cytokinetics, Inc. to develop drugs that activate cardiac myosins to improve cardiac contractility in patients suffering from heart failure. The first part of the lecture is directed to a general audience or a beginning graduate class.
In the second part of this lecture, I will discuss our laboratory's current work on the mechanism of movement by dynein, a motor protein about which we still know very little. This is a research story in progress, where some advances have been made. However, much remains to be done in order to understand how this motor works.
Ron Vale is Professor and Chair of Cellular and Molecular Pharmacology at the University of California, San Francisco, where he has been on faculty since 1987. He also has been an investigator of the Howard Hughes Medical Institute since 1995.
Vale received a B.A. degree in biology and chemistry from the University of California, Santa Barbara (1980), and a Ph.D. degree in neuroscience from Stanford University (1985). His graduate and postdoctoral studies at the Marine Biological Laboratory led to the discovery of kinesin, a microtubule-based motor protein.
Dr. Vale’s honors include the Pfizer Award in enzyme chemistry, the Young Investigator Award from the Biophysical Society, and election to the National Academy of Sciences and the American Academy of Arts and Sciences. In 2012, Vale shared the Lasker Award for Basic Medical Research. Besides studying the mechanism of motor proteins (the subject of this lecture), Vale’s laboratory using RNAi and high resolution microscopy to study mitosis and cell shape, examines signal transduction by single molecule microscopy, and biochemistry/cell biology of microtubule plus end binding proteins.
- Ron Vale iBioSeminar Part 3: Mining the Genome for Mitotic Treasures
- Ron Vale iBioMagazine: Molecular Motor Search