18 research outputs found
Direct, convergent hypersensitivity of calcium-activated force generation produced by hypertrophic cardiomyopathy mutant α-tropomyosins in adult cardiac myocytes
Use of pyrene-labelled actin to probe actin-Myosin interactions: kinetic and equilibrium studies
A Differential Equation Model for Tropomyosin-induced Myosin Cooperativity Describes Myosin–Myosin Interactions at Low Calcium
Actin cytoskeleton is responsible for the change of cytoplasmic organization in root hair cells induced by a protein phosphatase inhibitor, calyculin A
Adaptability of myosin V studied by simultaneous detection of position and orientation
We studied the structural dynamics of chicken myosin V by combining the localization power of fluorescent imaging with one nanometer accuracy (FIONA) with the ability to detect angular changes of a fluorescent probe. The myosin V was labeled with bifunctional rhodamine on one of its calmodulin light chains. For every 74 nm translocation, the probe exhibited two reorientational motions, associated with alternating smaller and larger translational steps. Molecules previously identified as stepping alternatively 74-0 nm were found to actually step 64-10 nm. Additional tilting often occurred without full steps, possibly indicating flexibility of the attached myosin heads or probing of their vicinity. Processive myosin V molecules sometimes shifted from the top to the side of actin, possibly to avoid an obstacle. The data indicate marked adaptability of this molecular motor to a nonuniform local environment and provide strong support for a straight-neck model of myosin V in which the lever arm of the leading head is tilted backwards at the prepowerstoke angle