Figure 5.
![Figure 5. [Ca2+]ER modulation of InsP3R-3 channel activity depends on magnitude of Ca2+ flux through the open-channel pore. (A) A typical single-channel lum-out nuclear patch-clamp current trace recorded during a switch of [Ca2+]ER from 70 nM to 300 µM in Vapp = +30 mV. Note that the change in channel current size as the result of the change in [Ca2+]ER was smaller. This is because of the reduction in Ca2+ flux through the channel by the positive Vapp. (B–D) Bar graphs of mean ratios of channel Po, to, and tc observed before and after [Ca2+]ER switches between 70 nM and 300 µM in Vapp = ±30 mV. ooo indicates statistically significant difference between the two ratios connected by the bracket (P < 0.005; unpaired t test).](https://cdn.rupress.org/rup/content_public/journal/jgp/140/6/10.1085_jgp.201210804/5/jgp_201210804r_fig5.jpeg?Expires=1773556049&Signature=vlH8kNI4QVCUX9CdJwJmQoSP6qjIxe0KM7k6Ys~QQ4NOO1rfeENrhiUQyEK9PYOzKGyxHU7I55u~LSi4GP4vZ5XgowJgV1Si1Nuqd1dUXchLniSeH6tPSaat45odprHC2z65OwFAlZE2t0KJio8TXWQBxsOrGXyRjr69Ym02MBYw-hytzHEq7IcdpMfTn919tTOJJNjnXMul~aa8R5cVP23mfr75UbKO6j1Ke7CRaCsMu9Moptfc~3UEyAZbxZzq1bfKBAzqAAHwSAz6-wjvFkd6M~o6Nmow~zLFqlghvEJ2IA3Ugcz~W1Ip8Y6OCUI2K6x6NnDgo-kIgJQpg6L4vw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
[Ca2+]ER modulation of InsP3R-3 channel activity depends on magnitude of Ca2+ flux through the open-channel pore. (A) A typical single-channel lum-out nuclear patch-clamp current trace recorded during a switch of [Ca2+]ER from 70 nM to 300 µM in Vapp = +30 mV. Note that the change in channel current size as the result of the change in [Ca2+]ER was smaller. This is because of the reduction in Ca2+ flux through the channel by the positive Vapp. (B–D) Bar graphs of mean ratios of channel Po, to, and tc observed before and after [Ca2+]ER switches between 70 nM and 300 µM in Vapp = ±30 mV. ooo indicates statistically significant difference between the two ratios connected by the bracket (P < 0.005; unpaired t test).
