A Sense of Direction

Science's STKE  30 Oct 2001:
Vol. 2001, Issue 106, pp. tw402
DOI: 10.1126/stke.2001.106.tw402

Intracellular signaling events that regulate chemotaxis are thought to be restricted to the edge of the cell that faces the highest concentration of attractant. However, a chemotactic Dictyostelium amoeba displays a constant and uniform surface distribution of its chemotactic receptors. Ueda et al. have used single-molecule imaging on live Dictyostelium cells to determine that the ligand binding kinetics of chemotactic receptors at the leading edge is different from other locations on the cell surface. Thus, the mechanism for directional sensing relies on differences in the signaling state of the receptors.

M. Ueda, Y. Sako, T. Tanaka, P. Devreotes, T. Yanagida , Single-molecule analysis of chemotactic signaling in Dictyostelium cells. Science 294, 864-867 (2001). [Abstract] [Full Text]