The small GTPase Rem is a potent negative regulator of high voltage-activated Ca 2+
channels and a known interacting partner for Ca 2+ channel accessory β subunits. The
mechanism for Rem-mediated channel inhibition remains controversial, although it has
been proposed that Ca V β association is required. Previous work has shown that a C-
terminal truncation of Rem (Rem-(1–265)) displays reduced in vivo binding to membrane-
localized β2a and lacks channel regulatory function. In this paper, we describe a role for the …