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Photoreceptor Discs: Built Like Ectosomes.

ABSTRACT: The light-sensitive outer segment organelle of the vertebrate photoreceptor cell is a modified cilium filled with hundreds of flattened 'disc' membranes that provide vast light-absorbing surfaces. The outer segment is constantly renewed with new discs added at its base every day. This continuous process is essential for photoreceptor viability. In this review, we describe recent breakthroughs in the understanding of disc morphogenesis, with a focus on the molecular mechanisms responsible for initiating disc formation from the ciliary membrane. We highlight the discoveries that this mechanism evolved from an innate ciliary process of releasing small extracellular vesicles, or ectosomes, and that both disc formation and ectosome release rely on the actin cytoskeleton.

SUBMITTER: Spencer WJ

PROVIDER: S-EPMC7584774 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

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Photoreceptor Discs: Built Like Ectosomes.

Spencer William J WJ Lewis Tylor R TR Pearring Jillian N JN Arshavsky Vadim Y VY

Trends in cell biology 20200906 11

The light-sensitive outer segment organelle of the vertebrate photoreceptor cell is a modified cilium filled with hundreds of flattened 'disc' membranes that provide vast light-absorbing surfaces. The outer segment is constantly renewed with new discs added at its base every day. This continuous process is essential for photoreceptor viability. In this review, we describe recent breakthroughs in the understanding of disc morphogenesis, with a focus on the molecular mechanisms responsible for ini ...[more]

PMID: 32900570

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Photoreceptor discs form through peripherin-dependent suppression of ciliary ectosome release.

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