Figure S3. ESYT1 is required for ER to mitochondria Ca²⁺ transfer.

(A) Trace of mitochondrial–aequorin measurements of mitochondrial Ca²⁺ upon histamine stimulation (100 μM) in control human fibroblasts, ESYT1 knock-out fibroblasts, ESYT1 knock-out fibroblasts expressing either ESYT1–Myc or an artificial mitochondria–ER tether. (B) Quantification of maximal mitochondrial Ca²⁺. Results are expressed as mean ± SD. From >50 cells per condition; n = 4 independent experiments. ns: not significant; **P < 0.01 (Turkey’s multiple comparisons test). (C) Quantification of the rate of mitochondrial Ca²⁺ uptake. Results are expressed as mean ± SD. From >50 cells per condition; n = 4 independent experiments. ns: not significant; *P < 0.05; **P < 0.01; ***P < 0.001 (Turkey’s multiple comparisons test). (D) Trace of cytosolic–aequorin measurements of cytosolic Ca²⁺ upon histamine stimulation (100 μM) in control human fibroblasts, ESYT1 knock-out fibroblasts, ESYT1 knock-out fibroblasts expressing either ESYT1–Myc or an mitochondria–ER artificial tether. (E) Quantification of maximal cytosolic Ca²⁺. Results are expressed as mean ± SD. From >50 cells per condition; n = 4 independent experiments. ns: not significant; *P < 0.05 (Turkey’s multiple comparisons test). (F) Quantification of the rate of cytosolic Ca²⁺ uptake. Results are expressed as mean ± SD. From >50 cells per condition; n = 4 independent experiments. ns: not significant; *P < 0.05; ***P < 0.001 (Turkey’s multiple comparisons test).