AMPAR/TARP stoichiometry differentially modulates channel properties.

ABSTRACT: AMPARs control fast synaptic communication between neurons and their function relies on auxiliary subunits, which importantly modulate channel properties. Although it has been suggested that AMPARs can bind to TARPs with variable stoichiometry, little is known about the effect that this stoichiometry exerts on certain AMPAR properties. Here we have found that AMPARs show a clear stoichiometry-dependent modulation by the prototypical TARP ?2 although the receptor still needs to be fully saturated with ?2 to show some typical TARP-induced characteristics (i.e. an increase in channel conductance). We also uncovered important differences in the stoichiometric modulation between calcium-permeable and calcium-impermeable AMPARs. Moreover, in heteromeric AMPARs, ?2 positioning in the complex is important to exert certain TARP-dependent features. Finally, by comparing data from recombinant receptors with endogenous AMPAR currents from mouse cerebellar granule cells, we have determined a likely presence of two ?2 molecules at somatic receptors in this cell type.

SUBMITTER: Miguez-Cabello F 

PROVIDER: S-EPMC7299370 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature