In mouse melanocytes, myosin Va is recruited onto the surface of melanosomes by a receptor complex containing Rab27a that is present in the melanosome membrane and melanophilin (Mlp), which links myosin Va to Rab27a. In this study, we show that Mlp is also a microtubule plus end–tracking protein or +TIP. Moreover, myosin Va tracks the plus end in a Mlp-dependent manner. Data showing that overexpression and short inhibitory RNA knockdown of the +TIP EB1 have opposite effects on Mlp–microtubule interaction, that Mlp interacts directly with EB1, and that deletion from Mlp of a region similar to one in the adenomatous polyposis coli protein involved in EB1 binding blocks Mlp's ability to plus end track argue that Mlp tracks the plus end directly by hitchhiking on EB1. These results identify a novel +TIP and indicate that vertebrate cells possess a +TIP complex that is similar to the Myo2p–Kar9p–Bim1p complex in yeast. We suggest that the +TIP complex identified in this study may serve to focus the transfer of melanosomes from microtubules to actin at the microtubule plus end.
Skip Nav Destination
Article navigation
24 October 2005
Report|
October 24 2005
Melanophilin and myosin Va track the microtubule plus end on EB1
Xufeng S. Wu,
Xufeng S. Wu
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
Search for other works by this author on:
Grace L. Tsan,
Grace L. Tsan
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
Search for other works by this author on:
John A. Hammer, III
John A. Hammer, III
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
Search for other works by this author on:
Xufeng S. Wu
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
Grace L. Tsan
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
John A. Hammer, III
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
Correspondence to John A. Hammer: [email protected]
Abbreviations used in this paper: APC, adenomatous polyposis coli protein; MBP, maltose-binding protein; Mlp, melanophilin; MTOC, microtubule-organizing center; RBD, Rab27a-binding domain; siEB1, short inhibitory RNA for EB1.
Received:
March 07 2005
Accepted:
September 15 2005
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Government
2005
J Cell Biol (2005) 171 (2): 201–207.
Article history
Received:
March 07 2005
Accepted:
September 15 2005
Connected Content
This article has been corrected
Correction: Melanophilin and myosin Va track the microtubule plus end on EB1
Citation
Xufeng S. Wu, Grace L. Tsan, John A. Hammer; Melanophilin and myosin Va track the microtubule plus end on EB1 . J Cell Biol 24 October 2005; 171 (2): 201–207. doi: https://doi.org/10.1083/jcb.200503028
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionEmail alerts
Advertisement
Advertisement