Steering in Quadruplet: The Complex Signaling Pathways Directing Chemotaxis

Abstract

Studies in the social amoeba Dictyostelium discoideum reveal that signaling cascades coordinating chemotactic directional sensing and migration are complex, with redundant pathways emerging as cells differentiate. Lack of accumulation of the leading-edge marker phosphatidylinositol-3,4,5-trisphosphate can be compensated by a pathway containing phospholipase A 2 (PLA 2 ) in early developed cells and guanylyl cyclase (GC) in later developed, polarized cells. Because numerous signaling networks operational during Dictyostelium chemotaxis are conserved in mammalian cells, PLA 2 and GC pathways may also be effective in higher eukaryotes, providing avenues for future research.