title: Dauer pheromone and G-protein signaling modulate the coordination of intraflagellar transport kinesin motor proteins in C. elegans.
abstract: Cilia length and function are dynamically regulated by modulation of intraflagellar transport (IFT). The cilia of C. elegans amphid channel neurons provide an excellent model to study this process, since they use two different kinesins for anterograde transport: kinesin-II and OSM-3 kinesin together in the cilia middle segments, but only OSM-3 in the distal segments. To address whether sensory signaling modulates the coordination of the kinesins, we studied IFT protein motility in gpa-3 mutant animals, since dominant active mutation of this sensory Galpha protein GPA-3QL) affects cilia length. In addition, we examined animals exposed to dauer pheromone, since dauer formation, which involves gpa-3, induces changes in cilia morphology. Live imaging of fluorescently tagged IFT proteins showed that in gpa-3 mutants and in larvae exposed to dauer pheromone, kinesin-II speed is decreased and OSM-3 speed is increased, whereas structural IFT proteins move at an intermediate speed. These results indicate that mutation of gpa-3 and exposure to dauer pheromone partially uncouple the two kinesins. We propose a model in which GPA-3-regulated docking of kinesin-II and/or OSM-3 determines entry of IFT particles into the cilia subdomains, allowing structural and functional plasticity of cilia in response to environmental cues.
authors.affiliation: Department of Cell Biology and Genetics, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Burghoorn
authors.forename: Martijn P J
authors.initials: MP
authors.lastname: Dekkers
authors.forename: Suzanne
authors.initials: S
authors.lastname: Rademakers
authors.forename: Ton
authors.initials: T
authors.lastname: de Jong
authors.forename: Rob
authors.initials: R
authors.lastname: Willemsen
authors.forename: Peter
authors.initials: P
authors.lastname: Swoboda
authors.forename: Gert
authors.initials: G
authors.lastname: Jansen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002923:Cilia / Q000235:genetics / Q000378:metabolism*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000235:genetics / Q000378:metabolism*; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D010675:Pheromones / Q000378:metabolism*; D021381:Protein Transport; D015398:Signal Transduction
chemical_list: D029742:Caenorhabditis elegans Proteins; C093002:OSM-3 protein, C elegans; D010675:Pheromones; C501263:gpa-3 protein, C elegans; C074152:kinesin-II; D016547:Kinesins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go