Melanosomes transported by myosin-V in Xenopus melanophores perform slow 35 nm steps.
We studied the motion of pigment organelles driven by myosin-V in Xenopus melanophores using a tracking technique with precision of 2 nm. The organelle trajectories showed occasional steps with a distribution centered at 35 nm and a standard deviation of 13 nm, in agreement with the step size of myosin-V determined in vitro. In contrast, trajectories of melanosomes in cells expressing a dominant negative form of myosin-V did not show steps. The step duration was in the range 20-80 ms, slower than what it would be expected from in vitro results. We speculate that the cytoplasm high viscosity may affect significantly the melanosomes' motion.
Levi
Valeria
V
Gelfand
Vladimir I
VI
Serpinskaya
Anna S
AS
Gratton
Enrico
E
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001703:Biophysics / Q000379:methods*; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D005799:Genes, Dominant; D016547:Kinesins / Q000737:chemistry; D020460:Melanosomes / Q000502:physiology*; D024701:Myosin Type V / Q000737:chemistry*; D015739:Nocodazole / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D014981:Xenopus
D000970:Antineoplastic Agents; D024701:Myosin Type V; D016547:Kinesins; D015739:Nocodazole