title: Role of SpdA in Cell Spreading and Phagocytosis in Dictyostelium.
abstract: Dictyostelium discoideum is a widely used model to study molecular mechanisms controlling cell adhesion, cell spreading on a surface, and phagocytosis. In this study we isolated and characterize a new mutant created by insertion of a mutagenic vector in the heretofore uncharacterized spdA gene. SpdA-ins mutant cells produce an altered, slightly shortened version of the SpdA protein. They spread more efficiently than WT cells when allowed to adhere to a glass substrate, and phagocytose particles more efficiently. On the contrary, a functional spdA knockout mutant where a large segment of the gene was deleted phagocytosed less efficiently and spread less efficiently on a substrate. These phenotypes were highly dependent on the cellular density, and were most visible at high cell densities, where secreted quorum-sensing factors inhibiting cell motility, spreading and phagocytosis are most active. These results identify the involvement of SpdA in the control of cell spreading and phagocytosis. The underlying molecular mechanisms, as well as the exact link between SpdA and cell spreading, remain to be established.
authors: Department for Cell Physiology and Metabolism, Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors: Marco
authors: M
authors: Dias
authors: Department for Cell Physiology and Metabolism, Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors: Cristiana
authors: C
authors: Brochetta
authors: Department for Cell Physiology and Metabolism, Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors: Anna
authors: A
authors: Marchetti
authors: Department for Cell Physiology and Metabolism, Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors: Romain
authors: R
authors: Bodinier
authors: Laboratoire des Matériaux et du Génie Physique (LMGP), UMR CNRS-Grenoble INP5628 Université Grenoble Alpes, 3 parvis Louis Néel, BP 257, Grenoble cedex 1, France.
authors: Franz
authors: F
authors: Brückert
authors: Department for Cell Physiology and Metabolism, Faculty of Medicine, Geneva University, Geneva, Switzerland.
authors: Pierre
authors: P
authors: Cosson
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D004023:Dictyostelium / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D010587:Phagocytosis / Q000502:physiology*; D010641:Phenotype; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins