mAbs and their sources included mouse anti-TYRP1 (TA99, also known as Mel-5; American Type Culture Collection) and mouse anti-Myc for dIFM (9E10; American Type Culture Collection), mouse anti-Pldn (clone 2G6; a generous gift from Esteban Dell’Angelica, University of California, Los Angeles, CA; Ghiani et al., 2010 (link)), mouse anti–AP-3δ (clone SA4; Developmental Studies Hybridoma Bank), rabbit anti-AP3M1 (ab201227; Abcam), mouse anti–γ-tubulin (GTU88; Sigma-Aldrich), mouse anti-VAMP7 (clone 158.2; Synaptic Systems), mouse anti-GFP (NB600-597, Novus Biologicals; or clones 7.1 and 13.1, Roche), and mouse anti-clathrin heavy chain (clone 23; BD Biosciences). Polyclonal antibodies included rabbit anti-STX13 (Prekeris et al., 1998 (link)), as previously described (Setty et al., 2007 (link)); rabbit anti-VAMP7 TG50, a kind gift from Thierry Galli (Verraes et al., 2018 (link)); rabbit αPep7h-msm to the cytoplasmic domain of TYR (Berson et al., 2000 (link)); rabbit anti-dysbindin (Starcevic and Dell’Angelica, 2004 (link)), a kind gift from Esteban Dell’Angelica; and sheep anti-TGN46 (Serotec). Species-specific secondary antibodies from donkey and conjugated to Alexa Fluor 488, Cy3, Alexa Fluor 594, and Alexa Fluor 647 were used for dIFM or to IRDye-790CW, IRDye-680LT, or HRP for immunoblotting (Jackson ImmunoResearch Laboratories, Inc.).