Cell Migration

Vesicles to Stream By

Science Signaling  16 Dec 2008:
Vol. 1, Issue 50, pp. ec429
DOI: 10.1126/scisignal.150ec429

Starving Dictyostelium discoideum cells align head to tail and migrate toward each other in lines or “streams” of cells. This streaming behavior requires the chemoattractant adenosine 3',5'-monophosphate (cAMP), cell surface G-protein coupled receptors for cAMP, and intracellular adenylyl cyclase (ACA) to generate cAMP. Using ACA tagged with yellow fluorescent protein (ACA-YFP) to monitor subcellular localization, Kriebel et al. demonstrated that vesicles positive for ACA were actively trafficked to the rear of polarized Dictyostelium cells. This asymmetrical distribution, which the authors demonstrated previously was necessary for streaming behavior, required an intact actin cytoskeleton and microtubule network, as well as clathrin assembly and de novo synthesis of ACA. Actively migrating cells secreted multivesicular bodies (MVBs) containing ACA, a process that was reduced by inhibitors of microtubule polymerization or of protein synthesis. The authors propose that these ACA-rich MVBs may act as chemoattractant-releasing exosomes and provide a “trail” for other migrating cells to follow.

P. W. Kriebel, V. A. Barr, E. C. Rericha, G. Zhang, C. A. Parent, Collective cell migration requires vesicular trafficking for chemoattractant delivery at the trailing edge. J. Cell Biol. 183, 949–961 (2008). [Abstract] [Full Text]