title: Adenylyl cyclase localization regulates streaming during chemotaxis.
abstract: We studied the role of the adenylyl cyclase ACA in Dictyostelium discoideum chemotaxis and streaming. In this process, cells orient themselves in a head to tail fashion as they are migrating to form aggregates. We show that cells lacking ACA are capable of moving up a chemoattractant gradient, but are unable to stream. Imaging of ACA-YFP reveals plasma membrane labeling highly enriched at the uropod of polarized cells. This localization requires the actin cytoskeleton but is independent of the regulator CRAC and the effector PKA. A constitutively active mutant of ACA shows dramatically reduced uropod enrichment and has severe streaming defects. We propose that the asymmetric distribution of ACA provides a compartment from which cAMP is secreted to locally act as a chemoattractant, thereby providing a unique mechanism to amplify chemical gradients. This could represent a general mechanism that cells use to amplify chemotactic responses.
authors.affiliation: Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Building 37/Room 1E24, Bethesda, MD 20892, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Kriebel
authors.forename: Valarie A
authors.initials: VA
authors.lastname: Barr
authors.forename: Carole A
authors.initials: CA
authors.lastname: Parent
mesh_terms: D000199:Actins / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000096:biosynthesis*; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D002478:Cells, Cultured; D002633:Chemotaxis; D000242:Cyclic AMP / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism / Q000502:physiology*; D018274:Electroporation; D015151:Immunoblotting; D008164:Luminescent Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors
chemical_list: D000199:Actins; D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D000242:Cyclic AMP; D000262:Adenylyl Cyclases