Fig. 5

Activation of TRPML1 promotes Zn²⁺ release from lysosomes and late endosomes, not synaptic vesicles. Average traces (±s.e.m.) of primary rat hippocampal neurons a coexpressing mCherry-TRPML1 and GZnP3, b expressing GZnP3-TRPML1, c coexpressing mCherry-TRPML1 and GZnP3-Rab7a, or d coexpressing mCherry-TRPML1 and synaptophysin-GZnP3, treated with 50 µM ML-SA1 at 0 s and 100 µM TPEN at 300 s. e Mean normalized GZnP3 signal (±s.e.m.) 30 and 290 s after ML-SA1 addition for cytosolic GZnP3 (n = 10 neuron soma), GZnP3-TRPML1 (n = 48 puncta from 5 neuron soma), GZnP3-Rab7a (n = 62 puncta from nine neuron soma), and synaptophysin-GZnP3 (syn-GZnP3; n = 45 puncta from three neurons). Two-tailed student’s t-tests with Bonferroni correction for multiple comparisons. f Average traces (±s.e.m.) of primary rat hippocampal neurons coexpressing mCherry-TRPML1 and cytosolic GZnP3 (green), GZnP3-Rab7a (blue), or expressing GZnP3-TRPML1 (magenta), treated with 200 µM GPN from -600 to -480 seconds (not shown). g Mean normalized GZnP3 signal (±s.e.m.) 30 and 290 s after ML-SA1 addition for cytosolic GZnP3 (n = 6 neuron soma), GZnP3-TRPML1 (n = 30 puncta from four neuron soma), GZnP3-Rab7a (n = 51 puncta from six neuron soma). One-tailed student’s t-tests with Bonferroni correction for multiple comparisons. 50 µM ML-SA1 (black arrow), 100 µM TPEN (white arrow). ***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