Department of Ophthalmology, Duke University, Durham, NC, USA.
Duke Eye Center, Durham, NC, USA.
Adv Exp Med Biol. 2023;1415:507-511. doi: 10.1007/978-3-031-27681-1_74.
The light-detecting organelle of the photoreceptor cell is a modified primary cilium, called the outer segment. The outer segment houses hundreds of light-sensitive membrane, "discs," that are continuously renewed by the constant formation of new discs at the outer segment base and the phagocytosis of old ones from outer segment tips by the retinal pigment epithelium. In this chapter, we describe how an actin cytoskeleton network, residing precisely at the site of disc formation, provides the driving force that pushes out the ciliary plasma membrane to form each disc evagination that subsequently can mature into a bona fide disc. We highlight the functions of actin-binding proteins, particularly PCARE and Arp2/3, that are known to participate in disc formation. Finally, we describe a working model of disc formation built upon the many studies focusing on the role of actin during disc morphogenesis.
光感受器细胞的光探测细胞器是一种经过修饰的初级纤毛，称为外节。外节包含数百个感光膜“盘”，这些“盘”由外节基部不断形成新的“盘”以及视网膜色素上皮细胞从外节尖端吞噬旧“盘”来持续更新。在本章中，我们描述了位于盘形成部位的肌动蛋白细胞骨架网络如何提供推动力，将纤毛质膜向外推出，形成每个盘状突起，随后这些突起可以成熟为真正的盘。我们强调了肌动蛋白结合蛋白的功能，特别是已知参与盘形成的 PCARE 和 Arp2/3。最后，我们描述了一个基于许多研究的盘形成工作模型，这些研究集中在肌动蛋白在盘形态发生过程中的作用。
