title: Light-dependent translocation of visual arrestin regulated by the NINAC myosin III.
abstract: The rhodopsin regulatory protein, visual arrestin, undergoes light-dependent trafficking in mammalian and Drosophila photoreceptor cells, though the mechanisms underlying these movements are poorly understood. In Drosophila, the movement of the visual arrestin, Arr2, functions in long-term adaptation and is dependent on interaction with phosphoinositides (PIs). However, the basis for the requirement for PIs for light-dependent shuttling was unclear. Here, we demonstrated that the dynamic trafficking of Arr2 into the phototransducing compartment, the rhabdomere, required the eye-enriched myosin III, NINAC. We showed that defects in ninaC resulted in a long-term adaptation phenotype similar to that which occurred in arr2 mutants. The interaction between Arr2 and NINAC was PI dependent and NINAC bound directly to PIs. These data demonstrate that the light-dependent translocation of Arr2 into the rhabdomeres requires PI-mediated interactions between Arr2 and the NINAC myosin III.
authors.affiliation: Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Craig
authors.initials: C
authors.lastname: Montell
mesh_terms: D000221:Adaptation, Ocular / Q000235:genetics*; D000818:Animals; D019390:Arrestins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism* / Q000648:ultrastructure; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D025102:Myosin Type III / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010716:Phosphatidylinositols / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D014785:Vision, Ocular / Q000235:genetics
chemical_list: D019390:Arrestins; D029721:Drosophila Proteins; D005136:Eye Proteins; D010716:Phosphatidylinositols; D010750:Phosphoproteins; D025102:Myosin Type III; C072308:ninaC protein, Drosophila; D018995:Myosin Heavy Chains