Melanosomes Transported by Myosin V in Xenopus Melanophores Perform Slow 35 nm Steps

LEVI V, GELFAND VI, SERPINSKAYA AS, GRATTON E

BIOPHYSICAL JOURNAL

CELL PRESS

Año: 2006 vol. 90 p. 7 - 9

0006-3495

ABSTRACT We studied the motion of pigment organelles driven by myosin-V in Xenopus melanophores using a trackingtechnique with precision of 2 nm. The organelle trajectories showed occasional steps with a distribution centered at 35 nm and astandard deviation of 13 nm, in agreement with the step size of myosin-V determined in vitro. In contrast, trajectories ofmelanosomes in cells expressing a dominant negative form of myosin-V did not show steps. The step duration was in the range20–80 ms, slower than what it would be expected from in vitro results. We speculate that the cytoplasm high viscosity may affectsignificantly the melanosomes’ motion