Nomenclature	ASIC1	ASIC2	ASIC3
HGNC, UniProt	ASIC1, P78348	ASIC2, Q16515	ASIC3, Q9UHC3
Endogenous activators (EC50)	Extracellular H+ (ASIC1a) (∼1.6x10-7 – 6.3x10-7 M), Extracellular H+ (ASIC1b) (∼6.3x10-7 – 8x10-6 M)	Extracellular H+ (∼1x10-5 – 8x10-5 M)	Extracellular H+ (transient component) (∼2x10-7 – 6.3x10-7 M), Extracellular H+ (sustained component) (∼5x10-5 – 3.5x10-4 M)
Activators (EC50)	–	–	GMQ (largely non-desensitizing; at pH 7.4) (∼1x10-3 M), arcaine (at pH 7.4) (∼1.2x10-3 M), agmatine (at pH 7.4) (∼9.8x10-3 M)
Channel Blockers (IC50)	psalmotoxin 1 (ASIC1a) (9x10-10 M), Zn2+ (ASIC1a) (∼7x10-9 M), Pb2+ (ASIC1b) (∼1.5x10-6 M), A317567 (ASIC1a) (∼2x10-6 M), Pb2+ (ASIC1a) (∼4x10-6 M), amiloride (ASIC1a) (1x10-5 M), benzamil (ASIC1a) (1x10-5 M), EIPA (ASIC1a) (1x10-5 M), nafamostat (ASIC1a) (∼1.3x10-5 M), amiloride (ASIC1b) (2.1x10-5 – 2.3x10-5 M), flurbiprofen (ASIC1a) (3.5x10-4 M), ibuprofen (ASIC1a) (∼3.5x10-4 M), Ni2+ (ASIC1a) (∼6x10-4 M)	amiloride (2.8x10-5 M), A317567 (∼3x10-5 M), nafamostat (∼7x10-5 M), Cd2+ (∼1x10-3 M)	APETx2 (transient component only) (6.3x10-8 M), nafamostat (transient component) (∼2.5x10-6 M), A317567 (∼1x10-5 M), amiloride (transient component only - sustained component enhanced by 200μM amiloride at pH 4) (1.6x10-5 – 6.3x10-5 M), Gd3+ (4x10-5 M), Zn2+ (6.1x10-5 M), aspirin (sustained component) (9.2x10-5 M), diclofenac (sustained component) (9.2x10-5 M), salicylic acid (sustained component) (2.6x10-4 M)
Radioligands (Kd)	[125I]psalmotoxin 1 (ASIC1a) (2.13x10-10 M)	–	–
Functional characteristics	ASIC1a: γ ∼14pS, PNa/PK = 5–13, PNa/PCa =2.5, rapid activation rate (5.8–13.7 ms), rapid inactivation rate (1.2–4 s) @ pH 6.0, slow recovery (5.3–13s) @ pH 7.4 ASIC1b: γ ∼ 19 pS, PNa/PK =14.0, PNa ≫ PCa, rapid activation rate (9.9 ms), rapid inactivation rate (0.9–1.7 s) @ pH 6.0, slow recovery (4.4–7.7 s) @ pH 7.4	γ∼10.4–13.4 pS, PNa/PK =10, PNa/PCa = 20, rapid activation rate, moderate inactivation rate (3.3–5.5 s) @ pH 5	γ∼ 13–15 pS; biphasic response consisting of rapidly inactivating transient and sustained components; very rapid activation (<5 ms) and inactivation (0.4s); fast recovery (0.4–0.6 s) @ pH 7.4, transient component partially inactivated at pH 7.2
Comment	ASIC1a and ASIC1b are also blocked by diarylamidines (IC50 ∼3 μM for ASIC1a)	ASIC2 is also blocked by diarylamidines	ASIC3 is also blocked by diarylamidines