Scientific article
English

Myosin VI regulates actin dynamics and melanosome biogenesis

Published inTraffic, vol. 13, no. 5, p. 665-680
Publication date2012-05
First online date2012-03-06
Abstract

Myosin VI has been implicated in various steps of organelle dynamics. However, the molecular mechanism by which this myosin contributes to membrane traffic is poorly understood. Here, we report that myosin VI is associated with a lysosome-related organelle, the melanosome. Using an actin-based motility assay and video microscopy, we observed that myosin VI does not contribute to melanosome movements. Myosin VI expression regulates instead the organization of actin networks in the cytoplasm. Using a cell-free assay, we showed that myosin VI recruited actin at the surface of isolated melanosomes. Myosin VI is involved in the endocytic-recycling pathway, and this pathway contributes to the transport of a melanogenic enzyme to maturing melanosomes. We showed that depletion of myosin VI accumulated a melanogenic enzyme in enlarged melanosomes and increased their melanin content. We confirmed the requirement of myosin VI to regulate melanosome biogenesis by analysing the morphology of melanosomes in choroid cells from of the Snell's waltzer mice that do not express myosin VI. Together, our results provide new evidence that myosin VI regulates the organization of actin dynamics at the surface of a specialized organelle and unravel a novel function of this myosin in regulating the biogenesis of this organelle.

Keywords
  • Actins / chemistry
  • Actins / metabolism
  • Animals
  • Cell Membrane / metabolism
  • Choroid / cytology
  • Cytoplasm / metabolism
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Melanosomes / metabolism
  • Mice
  • Mice, Transgenic
  • Microscopy, Electron / methods
  • Microscopy, Video / methods
  • Microtubules / metabolism
  • Models, Biological
  • Myosin Heavy Chains / chemistry
  • Myosin Heavy Chains / physiology
  • Myosins / metabolism
  • Pigmentation
Citation (ISO format)
LOUBERY, Sylvain Philippe et al. Myosin VI regulates actin dynamics and melanosome biogenesis. In: Traffic, 2012, vol. 13, n° 5, p. 665–680. doi: 10.1111/j.1600-0854.2012.01342.x
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
Journal ISSN1398-9219
11views
0downloads

Technical informations

Creation21/10/2024 14:39:53
First validation14/01/2026 14:32:53
Update14/01/2026 14:32:53
Status update14/01/2026 14:32:53
Last indexation14/01/2026 14:32:54
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack