Rho GTPase Activating Protein 26 (ARHGAP26)

GRAF is a multidomain protein that is necessary for the CLIC/GEEC endocytic pathway,^[4] the most prevalent clathrin-independent endocytic pathway discovered to date. By virtue of an N-terminal BAR domain, GRAF1 sculpts the endocytic membranes of this pathway into 40 nm diameter tubules and vesicles that allow uptake of extracellular fluid, GPI-linked proteins and certain bacterial exotoxins into cells. The role of dynamin in the CLIC/GEEC pathway is controversial, but GRAF1 interacts strongly with this protein and acute inhibition of dynamin action abrogates CLIC/GEEC endocytosis. There are several members of the GRAF family of proteins, including GRAF2, GRAF3 and oligophrenin, all of which likely play similar roles during clathrin-independent endocytic events.