Canonical transient receptor potential 3 channels regulate mitochondrial calcium uptake

Mitochondrial Ca2+ homeostasis is fundamental to regulation of mitochondrial membrane potential, ATP production, and cellular Ca2+ homeostasis. It has been known for decades that isolated mitochondria can take up Ca2+ from the extramitochondrial solution, but the molecular identity of the Ca2+ channels involved in this action is largely unknown. Here, we show that a fraction of canonical transient receptor potential 3 (TRPC3) channels is localized to mitochondria, a significant fraction of mitochondrial Ca2+ uptake that relies on extramitochondrial Ca2+ concentration is TRPC3-dependent, and the up-and down-regulation of TRPC3 expression in the cell influences the mitochondrial membrane potential. Our findings suggest that TRPC3 channels contribute to mitochondrial Ca2+ uptake. We anticipate our observations may provide insights into the mechanisms of mitochondrial Ca2+ uptake and advance understanding of the physiological role of TRPC3.