On Your Marks… Get Bound… Internalize!
Photoreceptor shedding and its phagocytosis by the retinal pigment epithelium is a crucial process in the renewal of the light-sensitive photoreceptor outer segments (POS). This internalization process shares many components used by macrophages in apoptotic cell clearance, but is unique in that this process is rhythmic. This chapter discusses the molecular mechanisms known so far to be involved in the journey of the POS that follows three sequential steps: particle recognition, binding, and internalization.
KeywordsRetinal pigment epithelium Photoreceptor outer segments Phagocytosis Daily rhythm αvβ5 integrin MFG-E8 FAK MerTK Annexin 2
- Finnemann SC, Rodriguez-Boulan E (1999) Macrophage and retinal pigment epithelium phagocytosis: apoptotic cells and photoreceptors compete for alphavbeta3 and alphavbeta5 integrins, and protein kinase C regulates alphavbeta5 binding and cytoskeletal linkage. J Exp Med 190:861–874PubMedCrossRefGoogle Scholar