Fab 6H3 , but not Ab 6H3 , can inhibit PTCH1 endocytosis. PTCH1-Flag transiently-transfected HEK293T cells were treated with PBS, native SHH-N, Ab 6H3 , and Fab 6H3 , respectively, for 3 h. After treatment, cell-surface PTCH1-Flag was labeled with Sulfo-NHS-SS-biotin and pulled down using streptavidin-agarose resin. Total and surface (non-internalized) PTCH1 were detected using anti-FLAG antibody. Endogenous β-actin was used as an internal control.
