title: An actin-dependent mechanism for long-range vesicle transport.
abstract: Intracellular transport is vital for the function, survival and architecture of every eukaryotic cell. Long-range transport in animal cells is thought to depend exclusively on microtubule tracks. This study reveals an unexpected actin-dependent but microtubule-independent mechanism for long-range transport of vesicles. Vesicles organize their own actin tracks by recruiting the actin nucleation factors Spire1, Spire2 and Formin-2, which assemble an extensive actin network from the vesicles' surfaces. The network connects the vesicles with one another and with the plasma membrane. Vesicles move directionally along these connections in a myosin-Vb-dependent manner to converge and to reach the cell surface. The overall outward-directed movement of the vesicle-actin network is driven by recruitment of vesicles to the plasma membrane in the periphery of the oocyte. Being organized in a dynamic vesicle-actin network allows vesicles to move in a local random manner and a global directed manner at the same time: they can reach any position in the cytoplasm, but also move directionally to the cell surface as a collective. Thus, collective movement within a network is a powerful and flexible mode of vesicle transport.
authors: Medical Research Council, Laboratory of Molecular Biology, Cambridge CB2 0QH, UK. mschuh@mrc-lmb.cam.ac.uk
authors: Melina
authors: M
authors: Schuh
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D000199:Actins / Q000502:physiology*; D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D022162:Cytoplasmic Vesicles / Q000378:metabolism*; D005260:Female; D000080865:Formins; D051379:Mice; D008817:Mice, Mutant Strains; D008840:Microfilament Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*
chemical_list: D000199:Actins; D000080865:Formins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C556674:Spir-2 protein, mouse; C493004:Spire1 protein, mouse; C549436:formin 2 protein, mouse