title: Role of PKD2 in rheotaxis in Dictyostelium.
abstract: The sensing of mechanical forces modulates several cellular responses as adhesion, migration and differentiation. Transient elevations of calcium concentration play a key role in the activation of cells following mechanical stress, but it is still unclear how eukaryotic cells convert a mechanical signal into an ion flux. In this study, we used the model organism Dictyostelium discoideum to assess systematically the role of individual calcium channels in mechanosensing. Our results indicate that PKD2 is the major player in the cell response to rheotaxis (i.e., shear-flow induced mechanical motility), while other putative calcium channels play at most minor roles. Mutant pkd2 KO cells lose the ability to orient relative to a shear flow, whereas their ability to move towards a chemoattractant is unaffected. PKD2 is also important for calcium-induced lysosome exocytosis: WT cells show a transient, 2-fold increase in lysosome secretion upon sudden exposure to high levels of extracellular calcium, but pkd2 KO cells do not. In Dictyostelium, PKD2 is specifically localized at the plasma membrane, where it may generate calcium influxes in response to mechanical stress or extracellular calcium changes.
authors: Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.
authors: Wanessa C
authors: WC
authors: Lima
authors: Biozentrum, University of Basel, Basel, Switzerland.
authors: Adrien
authors: A
authors: Vinet
authors: Biozentrum, University of Basel, Basel, Switzerland.
authors: Jean
authors: J
authors: Pieters
authors: Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.
authors: Pierre
authors: P
authors: Cosson
mesh_terms: D000595:Amino Acid Sequence; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects; D004023:Dictyostelium / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D005089:Exocytosis / Q000187:drug effects; D005492:Folic Acid / Q000494:pharmacology; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D040542:Mechanotransduction, Cellular / Q000187:drug effects; D008969:Molecular Sequence Data; D010802:Phylogeny; D021381:Protein Transport / Q000187:drug effects; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D012212:Rheology / Q000187:drug effects; D033081:Shear Strength; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D015800:Protozoan Proteins; D005492:Folic Acid; D002118:Calcium