Figure 12.

Proposed multiple open state model for ENaC to describe the separate effects of cleavage, sodium concentration and temperature. In this model we propose that there is a single closed state “C_0,” and multiple non-interacting open states “O₁…O_n.” This model explains how some means of increasing P_o are unchanged between isoforms (such as temperature), while others (such as activation by proteases) show distinct differences. It also accounts for the high baseline activity in low Na⁺ under conditions with little cleavage. See Discussion for details.