(D) Confocal images of live wild-type (control) and GRAMD1 TKO HeLa cells, expressing either wild-type EGFP-GRAM1b (WT) or mutant EGFP-GRAM1b (G187L), with or without SMase treatment (100 mU/ml for 1 hour at 37°C). Insets show at higher magnification the regions indicated by white dashed boxes. Note the recruitment of mutant EGFP-GRAM1b (G187L) to the PM even in wild-type HeLa cells at rest, which was further enhanced by SMase treatment. Scale bars, 10 µm. 