Journal of Cell Science 115, e503-e503 (2002)
© 2002 The Company of Biologists Limited
Myosin Vc (p. 991)
Class V myosin motors are thought to transport organelles along actin
filaments. Myosin Va functions in melanosome trafficking, docking in a manner
dependent on the GTPase Rab27a. Less is known about myosin Vb (Myo5b),
although it has been shown to interact with Rab11a and is implicated in
transferrin receptor recycling. Olga Rodriguez and Richard Cheney now report
the cloning and characterization of a third member of this class, myosin Vc
(Myo5c). Myo5c is ubiquitously expressed but particularly abundant in
epithelial cells. The authors find that overexpression of a dominant negative
Myo5c construct disrupts membrane trafficking of the transferrin receptor via
a Rab8-containing compartment to which Myo5c localizes. Interestingly,
dominant negative Myo5b affects recycling of transferrin receptor via
Rab11a-containing compartments. Since dominant negative Myo5c appears to have
no effect on this latter pathway, Rodriguez and Cheney suggest that two
independent mechanisms for transferrin receptor trafficking exist: a
Rab11a-Myo5b pathway and a Rab8-Myo5c pathway. They suggest that the latter is
probably important in polarized epithelial cells, in which Myo5c is most
abundantly expressed.
Related articles in JCS:
- Human myosin-Vc is a novel class V myosin expressed in epithelial cells
- Olga C. Rodriguez and Richard E. Cheney
JCS 2002 115: 991-1004.
[Abstract]
[Full Text]