title: Myosin Va and myosin VI coordinate their steps while engaged in an in vitro tug of war during cargo transport.
abstract: Myosin Va (myoV) and myosin VI (myoVI) are processive molecular motors that transport cargo in opposite directions on actin tracks. Because these motors may bind to the same cargo in vivo, we developed an in vitro "tug of war" to characterize the stepping dynamics of single quantum-dot-labeled myoV and myoVI motors linked to a common cargo. MyoV dominates its myoVI partner 79% of the time. Regardless of which motor wins, its stepping rate slows due to the resistive load of the losing motor (myoV, 2.1 pN; myoVI, 1.4 pN). Interestingly, the losing motor steps backward in synchrony with the winning motor. With ADP present, myoVI acts as an anchor to prevent myoV from stepping forward. This model system emphasizes the physical communication between opposing motors bound to a common cargo and highlights the potential for modulating this interaction by changes in the cell's ionic milieu.
authors.affiliation: Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA.
authors.forename: M Yusuf
authors.initials: MY
authors.lastname: Ali
authors.forename: Guy G
authors.initials: GG
authors.lastname: Kennedy
authors.forename: Daniel
authors.initials: D
authors.lastname: Safer
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Trybus
authors.forename: H Lee
authors.initials: HL
authors.lastname: Sweeney
authors.forename: David M
authors.initials: DM
authors.lastname: Warshaw
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D051379:Mice; D008954:Models, Biological; D018995:Myosin Heavy Chains / Q000378:metabolism*; D024701:Myosin Type V / Q000378:metabolism*; D034421:Sus scrofa
chemical_list: C089785:myosin VI; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D024701:Myosin Type V; D018995:Myosin Heavy Chains