Biology subjects

Moye, A. R.

Publications and source records attributed to Moye, A. R..

3 recordsLinked to original sources

bioRxiv2025

Ciliopathy-associated protein, CEP290, is required for ciliary necklace and outer segment membrane formation in retinal photoreceptors.

The most common genetic cause of the childhood blinding disease Leber Congenital Amaurosis is mutation of the ciliopathy gene CEP290. Though studied extensively, the photoreceptor-specific roles of CEP290 remain unclear. Using advanced microscopy techniques, we investigated the sub-ciliary localization of CEP290 and its role in mouse photoreceptors during development. CEP290 was found throughout the connecting cilium between the microtubules and membrane, with nine-fold symmetry. In the absence of CEP290 ciliogenesis occurs, but the connecting cilium membrane is aberrant, and sub-structures, such as the ciliary necklace and Y-links, are defective or absent throughout the mid to distal connecting cilium. Transition zone proteins AHI1 and NPHP1 were abnormally restricted to the proximal connecting cilium in the absence of CEP290, while others like NPHP8 and CEP89 were unaffected. Although outer segment disc formation is inhibited in CEP290 mutant retina, we observed large numbers of extracellular vesicles. These results suggest roles for CEP290 in ciliary membrane structure, outer segment disc formation and photoreceptor-specific spatial distribution of a subset of transition zone proteins, which collectively lead to failure of outer segment formation and photoreceptor degeneration.

cell biology↗

bioRxiv2023

Centriole and transition zone structures in photoreceptor cilia revealed by cryo-electron tomography

Primary cilia mediate sensory signaling in multiple organisms and cell types but have structures adapted for specific roles. Structural defects in them lead to devastating diseases known as ciliopathies in humans. Key to their functions are structures at their base: the basal body, the transition zone, the "Y-shaped links" and the "ciliary necklace". We have used cryo-electron tomography with subtomogram averaging and conventional TEM to elucidate the structures associated with the basal region of the "connecting cilia" of rod outer segments in mouse retina. The longitudinal variations in microtubule (MT) structures and the lumenal scaffold complexes connecting them have been determined, as well as membrane-associated transition zone structures: Y-shaped links connecting MT to the membrane, and ciliary beads connected to them that protrude from the cell surface and form a necklace-like structure. These results represent a clearer structural scaffold onto which molecules, identified genetics, proteomics, and superresolution fluorescence, can be placed in our emerging model of photoreceptor sensory cilia. SummaryCryo-electron tomography and subtomogram averaging reveal new structural features at the base of the light sensing cilia of retinal rods. These include the basal body, the Y-links between axoneme and membrane, and the ciliary necklace of the transition zone.

cell biology↗

bioRxiv2020

Superresolution microscopy reveals photoreceptor-specific subciliary location and function of Cep290

Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multi-organ syndromic ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used superresolution fluorescence microscopy and electron microscopy (TEM) to localize CEP290 in the CC and in primary cilia of cultured cells with sub-diffraction resolution, and to determine effects of CEP290 deficiency. Radially, CEP290 co-localizes with the microtubule doublets and extends beyond them. Longitudinally, it is distributed throughout the length of the CC but is strictly confined to the very base of primary cilia in hRPE-1 cells. We found Y-shaped links, the ciliary sub-structures between microtubules and membrane, at the base of the transition zone in primary cilia of epithelial cells and throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. They did not lead to loss of the Y-shaped links but caused changes in their structures. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.

cell biology↗