Fig. 7

TRPML1-mediated Zn²⁺ signals are higher in neurons and INS-1 cells than other mammalian cell types. a Representative traces of primary rat hippocampal neurons co-expressing GZnP3 and mCherry-TRPML1. Neurons were treated with 50 µM ML-SA1 at 0 s (black arrow) and 100 µM TPEN at 300 s (white arrow). b Representative traces of HeLa cells co-expressing GZnP3 and mCherry-TRPML1. Cells were treated as described in a. c Mean integrated GZnP3 signal (±s.e.m.) 300 s after ML-SA1 addition for both neurons (blue, n = 10 cells) and HeLa cells (magenta, n = 7). Two-tailed Student’s t-test. d Representative traces of primary rat hippocampal neurons co-expressing GCaMP5 and mCherry-TRPML1. Neurons were treated with 50 µM ML-SA1 at 0 s (black arrow) and 10 mM CaCl₂ at 300 s (gray arrow). e Representative traces of HeLa cells co-expressing GCaMP5 and mCherry-TRPML1. Cells were treated as described in d. f Mean integrated GCaMP5 signal (±s.e.m.) 180 s after ML-SA1 addition for both neurons (blue, n = 8) and HeLa cells (magenta, n = 12). Two-tailed Student’s t-test. g Mean GZnP3 signal maximum (±s.e.m.) 300 s after ML-SA1 addition for both TRPML1^WT and TRPML1^DDKK in neurons (blue; WT, n = 10; DDKK, n = 7), INS-1 cells (green; WT, n = 26; DDKK, n = 18), COS-7 cells (gray; WT, n = 18; DDKK, n = 9), and HeLa cells (magenta; WT, n = 7; DDKK, n = 6). One-way ANOVA with post-hoc Tukey HSD. ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05, n.s. not significant. p-values listed in italics above corresponding comparisons where applicable. Source data are provided as a Source Data file