First published online March 7, 2007
Journal of Cell Science 120, 601e (2007)
© The Company of Biologists Limited
Resetting a SNARE
Fusion of membrane-bound vesicles with target compartments is crucial for intracellular trafficking. v-SNAREs (soluble N-ethyl maleimide sensitive factor adaptor protein receptors) on vesicles and t-SNAREs on target compartments mediate each fusion event. Because the v-SNARE is transferred into the target compartment during fusion, it must be recycled to the donor compartment, but how? On p. 1028, Wanjin Hong and co-authors reveal the trafficking itinerary of VAMP4, a v-SNARE enriched in the trans-Golgi network (TGN) that functions in endosome-to-TGN trafficking. Using GFP-tagged VAMP4 and an anti-GFP antibody, the authors show that VAMP4 is endocytosed from the cell surface by clathrin-dependent pathways and passes through the early and recycling endosomes before being directly transported to the TGN. That is, VAMP4 – i.e. it is recycled to the endosomes from the TGN via the cell surface. Internalisation of VAMP requires the double double-leucine motif in its TGN-targeting signal whereas its transport from endosomes to the TGN involves the signal's acidic cluster. Thus, the authors conclude, the TGN-targeting signal of VAMP4 contains the sorting information necessary for efficient recycling of VAMP4 via a route that fits in with its role in trafficking.
Related articles in JCS:
- VAMP4 cycles from the cell surface to the trans-Golgi network via sorting and recycling endosomes
- Ton Hoai Thi Tran, Qi Zeng, and Wanjin Hong
JCS 2007 120: 1028-1041.
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