Figure 8.

(A) Ras-related protein 1 (Rap1) activity is reduced in retinal pigment epithelium (RPE) grown in contact with choroidal endothelial cells (CECs) compared with solo RPE. (B) (Left) RPE cells transfected with a constitutively active green fluorescent protein (GFP)-tagged Rap1 show more protein in the pull-down than wild-type (WT) Rap or controls, indicating greater activity; (Right) expression of Rap GTPase-activating proteins (RapGAP), which acts by promoting guanosine triphosphate (GTP) to guanosine diphosphate hydrolysis, reduces active Rap1.