Colocalization of FcαR with lamp-1 in clustered vesicles occurs in transfectants with WT γ chain but not in those with altered γ chain.

Transfectants expressing FcαR and either WT γ chain (WT gamma), γ chain with IIA ITAM (IIA ITAM), or γ chain with Y → F mutation (Y → F) were treated with anti-FcαR IgG1 mAb and FITC anti-mIgG1 (green) at 37°C, after which they were fixed, permeabilized, and counterstained with rat anti–lamp-1 and Cy3 antirat IgG (red). Yellow staining denotes areas of colocalized FcαR and lamp-1.