This web page was produced as an assignment for Gen677 at UW-Madison Spring 2013
Myosin Va
Conventional myosin is the protein that along with actin is responsible for muscle contractions [1]. Unconventional myosins however, are motor proteins that acts as intracellular cargo transporters moving all sorts of things around the cell including organelles, secretory and protein vesicles and mRNA [2]. This class of proteins is probably best know for its ability to "walk" along an actin cytoskeleton [2]. Class V myosins are found in a wide variety of eukaryotes and are essential for life [1]. These motor proteins move along actin filaments in a hand-over-hand fashion as seen in the video below.
|
There are three class V myosins in most mammals, Va, Vb and Vc [2]. Myosin Vb and Vc are primarily found in the epithelial tissues and are thought to be responsible for the recycling of endosomes in these cells [2]. Myosin Va is expressed in the brain as well as in melanocytes and when the protein is defective, causes neurological and pigmentation defects [1].
From YouTube 2009. Myosin V Molecular Motor. Retrieved From:
http://www.youtube.com/watch?v=KfEbuHCGIIo
http://www.youtube.com/watch?v=KfEbuHCGIIo
References
[1] Islam K., Chin HF., Olivares AO., Saunders LP., De la Cruz EM., Kapoor TM. (2010). Myosin V inhibitor based on privileged chemical scaffolds. Angew Chem Int Ed Engl 49(45):8484 - 8488.
[2] Trybus KM. (2008). Myosin V from head to tail. Cell Mol Life Sci. 65(9):1378 - 1389.
[3] Protein Data Bank. CRYSTAL STRUCTURE OF MYOSIN V MOTOR WITH ESSENTIAL LIGHT CHAIN - NUCLEOTIDE-FREE. Retrieved March 7, 2013. http://www.pdb.org/pdb/explore/explore.do?structureId=1oe9
[2] Trybus KM. (2008). Myosin V from head to tail. Cell Mol Life Sci. 65(9):1378 - 1389.
[3] Protein Data Bank. CRYSTAL STRUCTURE OF MYOSIN V MOTOR WITH ESSENTIAL LIGHT CHAIN - NUCLEOTIDE-FREE. Retrieved March 7, 2013. http://www.pdb.org/pdb/explore/explore.do?structureId=1oe9
Rebecca Blackburn, [email protected], 3/12/13