Stargazin and γ4 slow the channel opening and closing rates of GluA4 AMPA receptors.

ABSTRACT: As auxiliary subunits, transmembrane AMPA receptor regulatory proteins (TARPs) are known to enhance macroscopic current amplitude and alter kinetic properties of AMPA receptors on slow time scale, such as desensitization rate. Whether TARPs affect the rate of AMPA channel opening and closing, however, remains elusive. Using a laser-pulse photolysis technique, we investigated the effect of γ-2 (stargazin, a type 1a TARP) and γ-4 (a type 1b TARP) on the channel-opening and channel-closing rate constants (i.e., k_op and k_cl) of GluA4 homomeric channels. We found both TARPs slow the k_op and k_cl by 4-fold and 3-fold, respectively, without appreciable change of channel-opening probability, as compared with GluA4 channel alone. On the other hand, γ-4 has

SUBMITTER: Pierce VD 

PROVIDER: S-EPMC6606765 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature