Purchase this article with an account.
Christine Insinna, Quanlong Lu, Carolyn Ott, Jennifer Lippincott-Schwartz, Peter Jackson, Christopher Westlake; Membrane trafficking regulation of intracellular ciliogenesis initiation and progression in RPE-1 cells and photoreceptors. Invest. Ophthalmol. Vis. Sci. 2016;57(12):567.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Vision is carried out through a highly elaborated sensory cilium in photoreceptor cells. Defects in photoreceptor cilia formation/function cause human diseases commonly associated with retinal degeneration, which ultimately culminates in blindness. Ciliogenesis is a complex process involving the coordination of multiple assembly events including mother centriole to basal body transition, recruitment of vesicular membranes for ciliary membrane formation and intraflagellar transport proteins along with microtubule building blocks for axonemal elongation. Studies in photoreceptors and cultured immortalized human retinal pigment epithelium (RPE-1) cells have suggested that ciliogenesis proceeds through an intracellular process wherein vesicular membranes are recruited to the mother centriole to form early ciliary membrane structures, which subsequently fuse with the plasma membrane. To date, the molecular mechanisms governing ciliary membrane assembly remain poorly understood. Previously, we identified the function of the Rab11-Rab8 cascade in ciliary membrane formation of mammalian cells. Here we characterize the role of membrane curving proteins linked to Rab11 and Rab8, including the EHD (Eps15 homology domain containing) proteins and a subfamily of BAR domain containing proteins in early ciliogenesis events.
We performed genetic knockout experiments using zebrafish photoreceptors and other ciliated organs and RPE-1 cells to examine membrane reshaping roles in intracellular ciliogenesis. We determined the timing of arrival of membrane shaping proteins at the mother centriole using a live cell imaging approach. We also identified the requirement of these proteins for early ciliogenesis functions using super-resolution imaging and electron microscopy techniques.
EHD1 and F-BAR proteins function in membrane shaping important for assembling the ciliary vesicle, the precursor of the ciliary membrane. Furthermore these proteins regulate the uncapping of the distal end of the mother centriole needed to initiate axonemal assembly.
Our results demonstrate that membrane shaping regulators perform an essential role in the formative steps of the intracellular ciliogenesis pathway.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only