Biochemistry of Metabolism - Cell Biology

Myosin

Reading:

Textbook Reading: Voet, Voet  & Pratt p. 180-186;  Alberts et al., 4th Edition, Chapter 16. (See notes for particular page references.)

Some recent articles (optional reading): 

J. V. Small, T. Stradal, E. Vignal & K. Rottner (2002) "The lamellipodium: where motility begins," Trends in Cell Biol. 12: 112-120.
H. Higuchi & S. A. Endow (2002) "Directionality and processivity of molecular motors," Current Opinion in Struct. Biol. 14: 50-57.
A. Glading, D. A. Lauffenburger & A. Wells (2002) "Cutting to the chase: calpain proteases in cell motility," Trends in Cell Biol. 12: 46-54.
A. Yildiz, J. N. Forkey, S. A. McKinney, T. Ha, Y. E. Goldman & P. R. Selvin (2003) "Myosin V walks hand-over-hand: single fluorophore imaging with 1.5 nm localization," Science 300: 2061-2065.
R. D. Vale (2003) "Myosin V motor proteins: marching stepwise towards a mechanism," J. Cell Biol. 163: 445-450.
M. J. Tyska & M. S. Mooseker (2003) "Myosin-V motility: these levers were made for walking," Trends in Cell Biol. 13: 447-451.
E. M. De La Cruz & E. M. Ostap (2004) "Relating biochemistry and function in the myosin superfamily," Current Opinion in Cell Biol. 16: 61-67.
F. Buss, G. Spudich & J. Kendrick-Jones (2004) "Myosin VI: cellular functions and motor properties," Annu. Rev. Cell Dev. Biol. 20: 649-676.
F. J. Kull & S. A. Endow (2004) "A new structural state of myosin," Trends In Biochem. Sci. 29: 103-106.
Z. M. Jaffer & J. Chernoff (2004) "The cross-Rho'ds of cell-cell adhesion," J. Biol. Chem. 279: 35123-35126.
M. Vicente-Manzanares, D. J. Webb & A. R. Horwitz (2005) "Cell migration at a glance," J. Cell Sci. 118: 4917-4919.
M. Krendel & M. S. Mooseker (2005) "Myosins: tails (and heads) of functional diversity," Physiology 20: 239-251.
L. Bosgrasf & P. J. M. van Haastert (2006) "The regulation of myosin II in Dictyostelium," Eur. J. Cell Biol. 85: 969-979.
O. M. Hernandez, M. Jones, G. Guzman & D. Szczesna-Cordary (2007) "Myosin essential light chain in health and disease," Am. J. Physiol. Heart Circ. Physiol. H1643-H1654.

Potential Test Questions:

1.a. Diagram the structure of myosin II. What is its subunit composition, and what are the major structural features of the myosin heavy chains? What is the role of the head domain? Briefly describe the myosin nucleotide-binding domain.
b. Diagram and describe how small assemblies of myosin II form and cause relative movements of actin filaments. Briefly describe a specific example of a cellular motility process that involves myosin II.
c. How does the structure of myosin V differ from that of myosin II? What is meant by the statement that myosin V is a processive motor? What is the significance of the myosin V step length? How is its processive reaction mechanism suited to the role of myosin V?

2. You may be asked to briefly describe the postulated role of each of the following in ameboid movement. If relevant, include mention of where it tends to be localized relative to the leading edge or tail region of a moving cell: profilin, myosin I, myosin II, Arp2/3, cofilin, actin capping protein, G-actin, F-actin, PIP2, Ca++, calpains.

Copyright 1998-2007 by Joyce J. Diwan. All rights reserved.

Lecture Notes on
Myosin

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