ABSTRACT
CLC proteins are a family comprising anion channels and transporters. e acronym “CLC” stands for “ChLoride Channel,” and CLC-0, the curious double-barreled Cl− channel from the Torpedo electric organ, is the rst cloned member of the family (Jentsch et al., 1990; Miller and White, 1980). Strictly speaking, the acronym is a misnomer because we now know that many CLC homologues are actually not passive Cl− channels but secondary active Cl−/H+ antiporters (Accardi and Miller, 2004; Zifarelli and Pusch, 2007). us, we will be referring to these proteins as CLC channels and transporters, or just CLC proteins. All CLC proteins studied so far seem to share the same threedimensional architecture: they are homodimeric proteins with physically separate, but identical ion translocation pathways in each subunit.
