Moving towards a paradigm: common mechanisms of chemotactic signaling in Dictyostelium and mammalian leukocytes.
Chemotaxis, or directed migration of cells along a chemical gradient, is a highly coordinated process that involves gradient sensing, motility, and polarity. Most of our understanding of chemotaxis comes from studies of cells undergoing amoeboid-type migration, in particular the social amoeba Dictyostelium discoideum and leukocytes. In these amoeboid cells the molecular events leading to directed migration can be conceptually divided into four interacting networks: receptor/G protein, signal transduction, cytoskeleton, and polarity. The signal transduction network occupies a central position in this scheme as it receives direct input from the receptor/G protein network, as well as feedback from the cytoskeletal and polarity networks. Multiple overlapping modules within the signal transduction network transmit the signals to the actin cytoskeleton network leading to biased pseudopod protrusion in the direction of the gradient. The overall architecture of the networks, as well as the individual signaling modules, is remarkably conserved between Dictyostelium and mammalian leukocytes, and the similarities and differences between the two systems are the subject of this review.
Department of Cell Biology, Johns Hopkins University, School of Medicine, 725 N. Wolfe St., 114 WBSB, Baltimore, MD, 21205, USA.
Yulia
Y
Artemenko
Thomas J
TJ
Lampert
Peter N
PN
Devreotes
D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D004023:Dictyostelium / Q000378:metabolism*; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
D018797:Cell Cycle Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D015800:Protozoan Proteins; D043562:Receptors, G-Protein-Coupled; D058570:TOR Serine-Threonine Kinases