title: Co-existence of Ras activation in a chemotactic signal transduction pathway and in an autonomous wave - forming system.
abstract: The activation of Ras is common to two activities in cells ofDictyostelium discoideum: the directed movement in a gradient of chemoattractant and the autonomous generation of propagating waves of actin polymerization on the substrate-attached cell surface. We produced large cells by electric-pulse induced fusion to simultaneously study both activities in one cell. For imaging, a fluorescent label for activated Ras was combined with labels for filamentous actin, PIP3, or PTEN. Chemotactic responses were elicited in a diffusion gradient of cyclic AMP. Waves initiated at sites separate from the front of the cell propagated in all directions. Nevertheless, the wave-forming cells were capable of recognizing the attractant gradient and managed to migrate in its direction.
authors.affiliation: a Max Planck Institute of Biochemistry , Martinsried , Germany.
authors.forename: Mary
authors.identifier: 0000-0002-3230-4872
authors.initials: M
authors.lastname: Ecke
authors.affiliation: a Max Planck Institute of Biochemistry , Martinsried , Germany.
authors.forename: Günther
authors.identifier: 0000-0002-8348-1924
authors.initials: G
authors.lastname: Gerisch
mesh_terms: D000199:Actins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002459:Cell Fusion; D002633:Chemotaxis; D000242:Cyclic AMP / Q000378:metabolism; D004023:Dictyostelium / Q000502:physiology*; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D015398:Signal Transduction; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D000199:Actins; D018797:Cell Cycle Proteins; C489016:ras protein, Dictyostelium; D000242:Cyclic AMP; D051059:PTEN Phosphohydrolase; D018631:ras Proteins
keywords: PIP3; PTEN; Ras; actin waves; cell fusion; chemotaxis; excitable systems