title: Photoreceptor discs form through peripherin-dependent suppression of ciliary ectosome release.
abstract: The primary cilium is a highly conserved organelle housing specialized molecules responsible for receiving and processing extracellular signals. A recently discovered property shared across many cilia is the ability to release small vesicles called ectosomes, which are used for exchanging protein and genetic material among cells. In this study, we report a novel role for ciliary ectosomes in building the elaborate photoreceptor outer segment filled with hundreds of tightly packed "disc" membranes. We demonstrate that the photoreceptor cilium has an innate ability to release massive amounts of ectosomes. However, this process is suppressed by the disc-specific protein peripherin, which enables retained ectosomes to be morphed into discs. This new function of peripherin is performed independently from its well-established role in maintaining the high curvature of disc edges, and each function is fulfilled by a separate part of peripherin's molecule. Our findings explain how the outer segment structure evolved from the primary cilium to provide photoreceptor cells with vast membrane surfaces for efficient light capture.
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710.|Department of Pharmacology, Duke University, Durham, NC 27710.
authors.forename: Raquel Y
authors.identifier: 0000-0002-3119-7737
authors.initials: RY
authors.lastname: Salinas
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710.
authors.forename: Jillian N
authors.identifier: 0000-0002-5352-2852
authors.initials: JN
authors.lastname: Pearring
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710.
authors.forename: Jin-Dong
authors.identifier: 0000-0003-0427-0369
authors.initials: JD
authors.lastname: Ding
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710.|Department of Pharmacology, Duke University, Durham, NC 27710.
authors.forename: William J
authors.initials: WJ
authors.lastname: Spencer
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Department of Ophthalmology, Duke University, Durham, NC 27710 vadim.arshavsky@duke.edu.|Department of Pharmacology, Duke University, Durham, NC 27710.
authors.forename: Vadim Y
authors.identifier: 0000-0001-8394-3650
authors.initials: VY
authors.lastname: Arshavsky
mesh_terms: D000818:Animals; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D002923:Cilia / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D064531:Peripherins / Q000378:metabolism*; D010786:Photoreceptor Cells / Q000378:metabolism*
chemical_list: D064531:Peripherins