Sci. STKE, 27 August 2002
Cell Polarity Membrane Recycling and Motility
Motile cells can exhibit dynamic polarity, adjusting their movement in response to external cues. Such polarity is defined by the cell's leading edge, a protrusion that characterizes the front end of the cell and orients it in the proper direction. Thompson and Bretscher report that polarity in motile Dictyostelium discoideum amoebae depends on NEM-sensitive factor (NSF), a protein that regulates membrane transport. Amoebae expressing temperature-sensitive forms of NSF were not only unable to carry out normal endocytosis, pinocytosis, and phagocytosis at the restrictive temperature, but they also lost cell polarity and became immobile. Unlike normal motile cells, they were not able to cap cross-linked surface receptors. Just how NSF links membrane transport with cell polarity is unclear, but the authors propose that recycling of membrane at the front of the cell could establish an internal orienting signal that organizes the cytoskeleton for continued membrane delivery in that direction.
Citation: Membrane Recycling and Motility. Sci. STKE 2002, tw315 (2002).
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