NON-RECEPTOR ION CHANNELS
(see also ionotropic receptors)

• volume-sensitive osmolyte and anion channels (VSOACs)

Table of contents :

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voltage-gated ion channels (4x) Ca2+ channel (CCN) Na+ channel (SCN) K+ channel (KCN / KV) Cl- channel (CLCN)

nonvoltage-gated ion channels cyclic nucleotide gated (CNG) aquaporins ryanodine receptors (RYRs)

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• voltage-gated ion channels (4x)

ion	subunits	expressed in ...	activators	blockers
Ca2+ channel (CCN) (4 internal repeated domains, each has 6 TM regions : region 4 acts as a voltage sensor)	a1 subunit  a1A (L-type : P/Q type; nervous system) a1B (L-type : N-type) a1C (L-type) a1D (L-type) a1E a1F  a1G (T-type) a1H (T-type) a1I (T-type) a1S (L-type) a2 / d subunit  a2 / d 1 a2 / d 2 a2 / d 3 b subunit  b1 b2 b3 b4 g subunit  g1 g2 g3 g4 g5 g6 g7 g8 CatSper1 CatSper2	L-type :  T-type : peripheral pain receptors, spinal cord, ventroposterolateral (VPL) thalamocortical neurons	1,4-dihydropyridines (DHP) :  BAY K 8644 atrotoxin maitotoxin	Cd2+ Ni2+ La3+ high-voltage activated (HVA) / L-type / dihydropyridines receptor (DHPR) selective nondihydropyridine calcium antagonists (NDCA) : gabapentin (Neurontin®) pregabalin  calciseptine D-600 diarylaminopropylamine ether  bepridil (Vascor®) benzothiazepines  diltiazem (Cardizem®, Tiazac®, Cartia®, Dilacor®, Dilacor-XR®, Diltia®) phenylalkylamines  amipamil gallopamil (Procorum®) tiapamil verapamil (Azupamil®, Calan®, Cardibeltin®, Civicor®, Cordilox®, Covera-HS®, Durasoptin®, Isoptin®, Veramex®, Verelan®) piperazines  flunarizine (Sibelium®) ranolazine (Ranexa®) trimetazidine (Vastarel®) 1,4-dihydropyridines (DHP) calcium antagonists (DCA) amlodipine (Norvasc®, Lotrel®, Amlor®, Istin®) benzimidazolyl isradipine (Dynacirc®, Lomir®, Icaz®)  barnidipine (Dilacor®, Osipine®) benidipine  cinildipine (Cinalong®) efonidipine hydrochloride (Landel®)  felodipine (Feloday®, Plendil®) lacidipine (Lacipil®, Motens®) lercarnidipine (Lerdip®) manidipine (Calslot®) nicardipine (Cardene®, Perpidine®, ...) nifedipine (Adalat®, Procardia®) nilvadipine (Nivadil®) nimodipine (Sular®, Nimotop®, Admon®, Bloquel®, Norton®, Oxigen®, Periplum®, Regental®, Vasoactin®) nisoldipine (Baymycard®, Sular®) nitrendipine (Bayotensin®, Pressodipin®) taicatoxin (TCX)  b-bungarotoxin (b-BTX / BuTx) N-type w-conotoxin AM336 P/Q-type w-agatoxin Hololena toxin R-type SNX-482 low-voltage activated (LVA) / transient (T)-type selective ethosuximide (ESM) (Zarontin®) valproic acid (VPA) / n-dipropyl acetate (Depakene®, Convulex®, Depakine®, Depalept®, Epilim®, Ergenyl®, Leptilan®, Orfiril®, Valporal®) or valproate (Depakote®, Epival®, Elvetium®, Everiden®, Novoseven®, Valcote®, Valnar®) or sodium valproate (Depacon®, Valpro®) divalproex sodium (Depakote®, Epival®, Elvetium®, Everiden®, Novoseven®, Valcote®, Valnar®) kurtoxin zonisamide (Zonegran®)
Na+ channel (SCN) (4 repeated domains, each has 6 TM regions : region 4 acts as a voltage sensor)	type I  a b		aconitine batrachotoxins brevetoxins pumiliotoxin veratridine	chlorinated ethane derivative insecticides  1,2-dibromo-3-chloropropane (BBC) dichlorodiphenyltrichloroethane (DDT) / chlorophenothane endosulphon (Thiodan®) methoxychlor (Marlate®) tetrodotoxins  saxitoxins  ciguatoxins  grayanotoxins  magnificalysins  crotamine  d-conotoxin  m-conotoxin  palytoxin  codeine  disopyramide (Norpace®)  encainide (Enkaid®) flecainide (Tambocor®)  amides  dibucaine (Nupercainal®)  lidocaine / lignocaine (Xylocaine®; EMLA® is lidocaine 2.5% and prilocaine 2.5%)  prilocaine (Citanest®; EMLA® is lidocaine 2.5% and prilocaine 2.5%)  benzocaine (Americaine Anesthetic®; Cepacol Anesthetic® in combination with cetylpyridinium chloride)  bupivacaine (Marcaine®, Sensorcaine®)  mexiletine (Mexitil®)  morizicine (Ethmozine®)  procainamide (Procan SR®, Procanbid®) quinidine (Quinaglute®, Quinidex®, ...)  tocainide (Tonocard®)  etidocaine (Duranest®)  mepivacaine (Carbosen®, Carbocaina®, Carbocaine®; Carbocaina Con Adrenalina®  in combination with adrenaline)  pramoxine hydrochloride (Anusol®, Tronothane®, ...)  esters  cocaine procaine chlorhydrate (Novocain®)  tetracaine (Pontocaine®)  propafenone PO (Rythmol®, RytmoNorm®) => 5-OH-propafenone and N-deproprionyl-propafenone proparacaine (Alcaine®, Ophtaine®, ..)  ropivacaine (Naropin®)  oxybuprocaine / benoxinate (Minims®; Fluress® in combination with fluorescein sodium) chloroprocaine (Nesacaine®)  dyclonine hydrochloride (Dyclone®) carbamazepine (CBZ) (Epitol®, Atretol®, Carbium®, Teril®, Sirtal®, Telestin®, Timonil, Tegretol®, Carbatrol®, ...)  oxcarbamazepine (Trileptal®)  valproic acid (VPA) / n-dipropyl acetate  hydantoins :  phenytoin (PHT) / diphenylhydantoin (Dilantin®, Dilantina®, Diphenylan®, Di-Hydan®, Dintoina®, Epsolin®,Fenitoina®, Epanutin®, Epilantin®, Phenhydan®, Zentropil®)  mephenytoin (Mesantoin®) ethotoin (Peganone®) topiramate (Topamax®)  lamotrigine (Lamictal®)  zonisamide (Zonegran®)  pentobarbital (Nembutal®)
	type II a 1 2 b
	type III  a
	type IV  a b
	type V  a
	type VI / VII  a
	type VIII  a
	type IX  a
	type X  a
	type XI  a
K+ channel (KCN / KV)	related to the Drosophila melanogaster Shaker channel  A / KV1 1 / KV1.1 (homotetramer) 2 / KV1.2 3 / KV1.3 4 / 8 / KV1.4 5 / KV1.5 6 / KV1.6 7 / KV1.7 10 / KV1.10 AB 1 2 3 Shaker cognate b (Shab)-related subfamily (B) 1 2 Shaker cognate w (Shaw)-related subfamily (C) 1 / KV3.1 2 / KV3.2 (3 isoforms : KV3.2a, KV3.2b, KV3.2c) 3 / KV3.3 4 / KV3.4 Shaker cognate l (Shal)-related subfamily (D) 1 2 3		Kv1.1 is palmitoylated in the cytosolic portion of the S2-S3 linker domain at residue C243. An amino acid palmitoylation consensus motif (ACP/RSKT) that is present in multiple other members of the Shaker subfamily of K+ channels and in several other unrelated regulatory proteins (e.g., CD36, NOS2, and the mannose-6 phosphate receptor) that are known to be palmitoylated by thioester linkages at the predicted consensus site cysteine residueref.	amiodarone (Cordarone®, Pacerone®)  sotalol (Betapace®)  quinidine (Quinaglute®, Quinidex®, ...)  dofetilide (Tikosyn®)  ibutilide (Corvert®)  Stichodactyla toxin (ShK) b-bungarotoxin (b-BTX / BuTx) dendrotoxins pandinotoxins iberiotoxin MCD-peptide apamin margatoxin charybdotoxin Gaboon viper toxin phalloidin haloperidol (Serenace®)  phencyclidine / 1-phenyl-cyclohexylpyperidine (PCP)  phentolamine mesylate (Regitine®)  lidocaine / lignocaine (Xylocaine®)  4-aminopyridine (4-AP) / EL-970 (Avitrol®, Fampridine-SR®) Sr2+ Ba2+ Cs2+
	IsK-related causes delayed-rectifier K+ current in cardiac myocytes (E)  1 (mutations cause inherited long-QT syndrome) Q2 / KCNQ1 (mutations cause inherited long-QT syndrome) 1-like 2 3 4
	F  1
	G  1 2 / F2 3
	H  1 2 (mutations cause inherited long-QT syndrome) 3 4 5 6 7 8
	J  1 (KATP / ROMK) 2 3 4 5 (KATP) 6 / 7 8 (KATP) 9 10 (KATP) 11 (KATP); associated with ABCC8 / sulfonylurea receptor 1 (SUR1) in b-cells of pancreatic Langerhans' islets) 12 (KATP) 13 14 15 (KATP) 16 inhibitor 1		diazoxide (Hyperstat IV®, Proglycem®)  minoxidil N-O sulfate (Loniten®, Rogaine®, Rogaine Extra Strength For Men®)  nicorandil (Sigmart®, Ikorel®)  pinacidil (Pindac®)
	K (two-pore)  1 2 3 4 5 6 / 8 7 9 10 11 / 14 / 15 12 13 16 17		halothane (Fluothane®)  enflurane (Ethrane®)  isoflurane (Forane®)  desflurane (Suprane®)  sevoflurane (Ultane®)  nitrous oxide / dinitrogen monoxide / N2O
	M (large conductance KCa) A1 B 1 2 3 4			zoxazolamine (Flexin®)
	N (intermediate/small  conductance KCa)  1 2 3 4 / Gardos			clotrimazole ICA 17043
	Q / KV7. 1 / A9 2 3 4 5		retigabine [D23129; N-(2-amino-4-(4-fluorobenzylamino)-phenyl)carbamic acid ethyl ester]
	S  1 2 3
	V  1 / B3
	Kv11.1
	Kv6.3
Cl- channel (CLCN)	CLCN1	skeletal muscle		niflumic acid (NFA) (Niflam®) (for Ca2+-activated Cl- channels)
	CLCN2
	CLCN3
	CLCN4	neuron
	CLCN5	kidney
	CLCN6
	CLCN7
	CLCNKA	thin ascending limb of the Henle loop (tAL) in the inner medulla
	CLCNKB	kidney

• nonvoltage-gated ion channels

ion	subunits	expressed in ...	activators	blockers
cyclic nucleotide gated (CNG) non-selective cation channel (6Na+:1Ca2+) with 3A:1B stoichiometry	a1
	a2
	a3
	a4 / b2
	b1
	b3
	aquaporin 0 (AQP0) / major intrinsic protein (MIP) of lens fiber (the only aquaporin known to form membrane junctions in vivoref)	lens-specific
aquaporins / aqua-glycerolporins : the structure of these channels reveals a tripathic channel that supports a hydrophobic surface and, opposite to this, a line of 8 hydrogen-bond acceptors and 4 hydrogen-bond donors. The 8 carbonyls act as acceptors for water (or glycerol OH) molecules. The central water molecule in the channel is oriented to polarize hydrogen atoms outward from the center. This arrangement suggests how the structure prevents the potentially lethal conduction of protons across the membrane. The structure also suggests the mechanism behind the selectivity of aquaglyceroporins for glycerol, the basis for enantioselectivity among alditols, and the basis for the prevention of any leakage of the electrochemical gradient.	aquaporin 1	RBC, proximal tubule, descending thin limb of the loop of Henle, and vasa recta		mercurial sulfhydryl-reactive compounds
	aquaporin 2 (translocation to plasma membrane is induced by antidiuretic hormone (ADH) via V2)	apical membrane of principal cells of collecting duct		mercurial sulfhydryl-reactive compounds
	aquaporin 3	basolateral membrane of principal cells of collecting duct		mercurial sulfhydryl-reactive compounds
	aquaporin 4	basolateral membrane of principal cells ofcollecting duct, brain		mercurial sulfhydryl-reactive compounds
	aquaporin 5	salivary and lachrymal glands, pneumocytes		mercurial sulfhydryl-reactive compounds
	aquaporin 6	kidney		mercurial sulfhydryl-reactive compounds
	aquaporin 7	adipocyte (hydrolysis of triglycerides results in the release of free fatty acids and glycerol)ref, sperm		mercurial sulfhydryl-reactive compounds
	aquaporin 8	pancreas, colon		mercurial sulfhydryl-reactive compounds
	aquaporin 9	WBC		mercurial sulfhydryl-reactive compounds
	aquaporin 10	epithelia		mercurial sulfhydryl-reactive compounds
amiloride-sensitive epithelial sodium channel (ENaC)	a b d g			amiloride (Midamor®; in combination with hydrochlorothiazide in Moduretic®) triamterene (Dyrenium®, Maxzide®)
degenerin (K+, Li+)				amiloride (Midamor®; in combination with hydrochlorothiazide in Moduretic®)
ryanodine receptors (RYRs) (Ca2+)	RYR1	skeletal muscles	ryanodine at nM concentrations  caffeine	ryanodine at mM concentrations  dantrolene (Dantrium®)
	RYR2	cardiomyocytes		ryanodine at mM concentrations
	RYR3	brain		ryanodine at mM concentrations
calcium-activated non-selective channels
stretch-activated (SA) non-selective cation channels
transient receptor potential cation channel, subfamily V, member 1 (TRPV1) / vanilloid receptor subtype 1 (VR1)		immature dendritic cells	capsaicin ;  increases in temperature in the noxious range	capsazepine

•  Web resources
• The ion channel webpage
• Cation channels

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