Migrating fibroblasts perform polarized, microtubule-dependent exocytosis towards the leading edge.
Cell migration might involve biased membrane traffic toward the leading edge to facilitate the building of extracellular matrix, membrane protrusions and adhesion plaques. We tested the hypothesis that secretory vesicles are preferentially delivered toward the leading lamella in wound-edge fibroblasts. Single fusion events of vesicles containing LDLR-GFP were mapped by total internal reflection fluorescence microscopy (TIR-FM). In migrating fibroblasts, exocytic events were polarized towards the leading edge. After disrupting microtubules with nocodazole, exocytosis continued, but fusion sites were clustered around central Golgi elements; there was no peripheral exocytosis. We conclude that microtubules are necessary for the domain-specific fusion of post-Golgi vesicles with the plasma membrane during migration.
Schmoranzer
Jan
J
Laboratory of Cellular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Kreitzer
Geri
G
Simon
Sanford M
SM
D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D002465:Cell Movement; D016764:Cell Polarity / Q000502:physiology*; D002478:Cells, Cultured; D003599:Cytoskeleton; D005089:Exocytosis / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000502:physiology; D008561:Membrane Fusion / Q000502:physiology; D008845:Microinjections; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000502:physiology*; D015739:Nocodazole / Q000494:pharmacology; D011554:Pseudopodia / Q000502:physiology*; D022142:Secretory Vesicles / Q000502:physiology; D014945:Wound Healing / Q000502:physiology
D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D015739:Nocodazole