Mechanisms of LD motility.
(A, B) LDs are transported as direct cargo by molecular motors along cytoskeletal filaments: transport along actin filaments is driven by plus-end directed Myosins (A); transport along microtubules can be unidirectional towards either the plus-or minus end (powered by Kinesin-1 or Cytoplasmic Dynein, respectively) or bidirectional, using both types of motors (B). (C) LDs hitchhike on other organelles that are transported by motors along microtubules. (D) Molecular motors promote bulk flow of the cytoplasm that drags many organelles, including LDs, along. (E) Polymerization of actin filaments may push LDs through the cytoplasm. (F) Myosin II may move LDs indirectly, by sliding actin filaments with attached LDs against each other. (G). LD moving by Brownian motion until it is captured by a tether on a target organelle.