Molecular basis for photoreceptor outer segment architecture

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• 作者：Andrew F.X. Goldberg^a ; ^{goldberg@oakland.edu" class="auth_mail" title="E-mail the corresponding author} ; Orson L. Moritz^b ; David S. Williams^c
• 关键词：Photoreceptor ; Outer segment ; Cilia ; Membrane curvature ; Retinal degeneration ; Tetraspanin
• 刊名：Progress in Retinal and Eye Research
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：55
• 期：Complete
• 页码：52-81
• 全文大小：4351 K

文摘

To serve vision, vertebrate rod and cone photoreceptors must detect photons, convert the light stimuli into cellular signals, and then convey the encoded information to downstream neurons. Rods and cones are sensory neurons that each rely on specialized ciliary organelles to detect light. These organelles, called outer segments, possess elaborate architectures that include many hundreds of light-sensitive membranous disks arrayed one atop another in precise register. These stacked disks capture light and initiate the chain of molecular and cellular events that underlie normal vision. Outer segment organization is challenged by an inherently dynamic nature; these organelles are subject to a renewal process that replaces a significant fraction of their disks (up to ∼10%) on a daily basis. In addition, a broad range of environmental and genetic insults can disrupt outer segment morphology to impair photoreceptor function and viability. In this chapter, we survey the major progress that has been made for understanding the molecular basis of outer segment architecture. We also discuss key aspects of organelle lipid and protein composition, and highlight distributions, interactions, and potential structural functions of key OS-resident molecules, including: kinesin-2, actin, RP1, prominin-1, protocadherin 21, peripherin-2/rds, rom-1, glutamic acid-rich proteins, and rhodopsin. Finally, we identify key knowledge gaps and challenges that remain for understanding how normal outer segment architecture is established and maintained.