Figure 1. PTP4A3, but not PTP4A1, colocalizes with LC3-positive puncta and promotes AP accumulation upon CQ-mediated autophagic degradation inhibition. (A and B) CHO cells overexpressing myc-PTP4A1 (CHO-PTP4A1) (A) or myc-PTP4A3 (CHO-PTP4A3) (B) were transfected with EGFP-LC3 reporter construct, and allowed to grow for 24 h. The transfected cells were treated with or without CQ in full media for another 24 h before immunostaining with an anti-myc antibody (scale bar: 20 μm). (C) CHO control (CHO-Con), CHO-PTP4A1, and CHO-PTP4A3 were treated with or without CQ for 24 h prior to immunostaining for LC3 (green) and actin (red). Representative images are shown in the left panel (scale bar: 20 μm). (D) LC3 puncta intensity of at least 20 cells from 5 distinct viewing fields were quantified as described in Materials and Methods, and presented as a histogram in the right panel (mean ± S.D.). ***P < 0.001.