Nomenclature	ClC‐1	ClC‐2
HGNC, UniProt	CLCN1, P35523	CLCN2, P51788
Endogenous activators	–	arachidonic acid
Activators	–	lubiprostone, omeprazole
Channel blockers	9‐anthroic acid, S‐(‐)CPB, S‐(‐)CPP, Cd2+, Zn2+, fenofibric acid, niflumic acid	GaTx2 (pK d 10.8) [voltage dependent ‐100mV], Cd2+, NPPB, Zn2+, diphenylamine‐2‐carboxylic acid
Functional Characteristics	γ = 1–1.5 pS; voltage‐activated (depolarization) (by fast gating of single protopores and a slower common gate allowing both pores to open simultaneously); inwardly rectifying; incomplete deactivation upon repolarization, ATP binding to cytoplasmic cystathionine β‐synthetase related (CBS) domains inhibits ClC‐1 (by closure of the common gate), depending on its redox status	γ = 2–3 pS; voltage‐activated by membrane hyperpolarization by fast protopore and slow cooperative gating; channels only open negative to ECl resulting in steady‐state inward rectification; voltage dependence modulated by permeant anions; activated by cell swelling, PKA, and weak extracellular acidosis; potentiated by SGK1; inhibited by phosphorylation by p34(cdc2)/cyclin B; cell surface expression and activity increased by association with Hsp90
Comments	CIC‐1 is constitutively active	CIC‐2 is also activated by amidation