A Molecular Network for the Transport of the TI-VAMP/VAMP7 Vesicles from Cell Center to Periphery

• DOI: 10.1016/j.devcel.2012.04.019
• Publication Date: 2012-06-14T16:39:43Z
• Authors: Andrea Burgo; Véronique Proux-G...; Emmanuel Sotirakis; Philippe Bun; Alessandra Casano; Agathe Verraes; Ronald K.H. Liem; Etienne Formstecher; Maïté Coppey-Moisan; Thierry Galli
• Keywords: Rab; Vesicle fusion; Vesicular Transport Proteins; Molecular motor

The compartmental organization of eukaryotic cells is maintained dynamically by vesicular trafficking. SNARE proteins play a crucial role in intracellular membrane fusion and need to be targeted to their proper donor or acceptor membrane. The molecular mechanisms that allow for the secretory vesicles carrying the v-SNARE TI-VAMP/VAMP7 to leave the cell center, load onto microtubules, and reach the periphery to mediate exocytosis are largely unknown. Here, we show that the TI-VAMP/VAMP7 partner Varp, a Rab21 guanine nucleotide exchange factor, interacts with GolginA4 and the kinesin 1 Kif5A. Activated Rab21-GTP in turn binds to MACF1, an actin and microtubule regulator, which is itself a partner of GolginA4. These components are required for directed movement of TI-VAMP/VAMP7 vesicles from the cell center to the cell periphery. The molecular mechanisms uncovered here suggest an integrated view of the transport of vesicles carrying a specific v-SNARE toward the cell surface.