Ca2+ channel properties of the mink ryanodine receptor type 3 (RyR3), expressed in HEK293 cells, were studied in planar lipid bilayers to which RyR3 rich membrane fragments had been fused. RyR3 channels were not active at resting levels of Ca2+(free) but were gated by an additional 1 mM ATP, exhibiting long open times. The second major finding was the absence of channel inactivation at millimolar Ca2+(free). Insertion of a myc tag at the N-terminus of RyR3 did not affect the channel properties. As to skeletal muscle, the observed type 3 channel properties appear physiologically meaningful by assisting type 1 channels in calcium release. Copyright (C) 2000 Federation of European Biochemical Societies.
Manunta, M., Rossi, D., Simeoni, I., Butelli, E., Romanin, C., Sorrentino, V., & Schindler, H. (2000). ATP-induced activation of expressed RyR3 at low free calcium. FEBS Letters, 471(2–3), 256–260. https://doi.org/10.1016/S0014-5793(00)01385-5