FIGURE 9.

Model of strategies for correct melanosome localization in the cell. A, schematic diagram of a melanosome dendritic protrusion. Mature melanosomes can undergo bidirectional transport along microtubules by using either kinesin for anterograde movement or dynein for retrograde transport. At the interface with the cortical actin network at the cell periphery melanosomes are transferred and tethered to actin by the action of myoVa and Mlph. Transport through the cortical actin mesh to the plasma membrane requires both the tethering action of Mlph as well as the motor properties of myoVa. B, tethering to actin has to both outweigh the propensity of the microtubule-based transporters to carry melanosomes back to the cell body and prevent dissociation and diffusion away from the cell cortex. MyoVa-directed transport has to counterbalance tethering forces to allow for adequate transport and distribution of melanosomes within the cell cortex.