Making sense of melanosome dynamics in mouse melanocytes.
Molecular motors drive most if not all organelle movements in Eukaryotic cells. These proteins are thought to bind to the organelle surface and, through the action of their mechanochemical domains, to translocate the organelle along a cytoskeletal track. In the case of the myosin family of molecular motors, the cytoskeletal track is filamentous actin. Microtubules serve as the cytoskeletal track for the kinesins and dyneins. While a considerable amount is known about the motors and tracks responsible for the bi-directional movement of pigment granules in fish and frog melanophores, relatively little is known about how melanosomes in mammalian melanocytes are transported out the cells dendritic arbor, accumulated at the ends of these dendrites, and transferred to keratinocytes. In this short review, we focus on the use of video microscopy to address these questions in mouse melanocytes, and we describe how an analysis of melanosome dynamics within wild type and dilute melanocytes shaped our thinking regarding the role of an unconventional myosin in melanosome transport and distribution.
Wu
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Laboratory of Cell Biology, National Institutes of Health, Bethesda, Maryland 20892-0301, USA. wux@helix.nih.gov
Hammer
J A
JA
D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D007381:Intermediate Filament Proteins / Q000502:physiology*; D008544:Melanocytes / Q000166:cytology / Q000648:ultrastructure*; D020460:Melanosomes / Q000502:physiology* / Q000648:ultrastructure; D051379:Mice; D018715:Microscopy, Video; D020409:Molecular Motor Proteins / Q000502:physiology*; D009068:Movement; D018995:Myosin Heavy Chains; D024701:Myosin Type V
D007381:Intermediate Filament Proteins; D020409:Molecular Motor Proteins; C513082:Myo5a protein, mouse; D024701:Myosin Type V; D018995:Myosin Heavy Chains