Figure 1. TFEB overexpression increases lysosomal localization to the plasma membrane, decreasing capacitative Ca²⁺ entry.

(A) Representative images and quantification of the distance of lysosomes from the plasma membrane, normalized to the cellular area, in HeLa cells co-transfected with pcDNA3 (control) or TFEB3xflag (TFEB) and LAMP1-GFP (green) for 48 h; the plasma membrane is stained with the FM4-64fx colorant (red) (pcDNA3 n = 12, TFEB n = 15). (B) Capacitative Ca²⁺ entry was measured using cytosolic aequorin in control HeLa cells (pcDNA3) or HeLa cells overexpressing TFEB for 48 h after Ca²⁺ (CaCl₂ 50 μM) administration (pcDNA3 n = 17, TFEB n = 20). (C) Capacitative Ca²⁺ entry was measured using PM-targeted aequorin in control HeLa cells (pcDNA3) or HeLa cells overexpressing TFEB after Ca²⁺ (50 μM) administration (n = 10 for each condition). Data are presented as the means ± SEM, ***p < 0.001. a.u.c. = area under the curve.