Actin filaments in apical projections of the primate pigmented epithelial cell.
A highly-ordered array of filaments is found within the apical processes of retinal pigmented epithelial cells in monkeys and humans. These filaments, approximately 100 A in diameter and 250 A apart, line the cytoplasmic face of the plasma membrane, in parallel with the long axis of the apical processes. Since these filaments bind rabbit myosin subfrafment-1 to form arrowhead complexes, we conclude that they contain actin. Such membrane-bound actin filaments could have any of several different functions: they could stabilize the apical projections and by so doing play a cytoskeletal role, and/or they could take part in the phagocytosis of shed outer segment discs.
D000199:Actins / Q000502:physiology; D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D004847:Epithelial Cells; D004848:Epithelium / Q000648:ultrastructure; D000882:Haplorhini; D006801:Humans; D010857:Pigment Epithelium of Eye / Q000648:ultrastructure*; D012160:Retina / Q000502:physiology / Q000648:ultrastructure*; D012453:Saimiri
D000199:Actins