Ion channels: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
Michal Harel (talk | contribs) No edit summary |
||
| (18 intermediate revisions by 2 users not shown) | |||
| Line 5: | Line 5: | ||
== Ion channel types == | == Ion channel types == | ||
Most ion channels are specific to an ion, like the '''sodium channels''', or the [[Potassium Channel]]<ref>PMID:19165895</ref>.<br /> | Most ion channels are specific to an ion, like the '''sodium channels''', or the [[Potassium Channel]]<ref>PMID:19165895</ref>.<br /> | ||
'''TRP channels''' let through various cations<ref>PMID:17579562</ref>.<br /> | *'''TRP channels''' let through various cations<ref>PMID:17579562</ref>.<br /> | ||
Another property of ion channels is that they can be either driven by voltage or by concentration gradients, or they can be gated (by voltage, ligands, touch and other sensory signal). '''Potassium channels''' (KCh) are subdivided to voltage-gated KCh and calcium-dependent KCh. The latter are subdivided into high- (BK, LKCa), intermediate- and small-conductance KCh (human SK1, rat SK2, SKCa). | Another property of ion channels is that they can be either driven by voltage or by concentration gradients, or they can be gated (by voltage, ligands, touch and other sensory signal).<br /> | ||
'''MthK''' is a calcium-dependent potassium channel from ''Methanobacterium thermoautrophicum''<ref>PMID:16735753</ref>.<br /> | *'''Potassium channels''' (KCh) are subdivided to voltage-gated KCh and calcium-dependent KCh. The latter are subdivided into high- (BK, LKCa), intermediate- and small-conductance KCh (human SK1, rat SK2, SKCa). See: [[Potassium Channel|Potassium channels]].<br /> | ||
'''MscL''' and '''MscS''' are large- and small-conductance mechanosensitive channels which protect bacteria from osmotic shock by allowing ions to flow across the cell membrane<ref>PMID:12046893</ref>. See [[Mechanosensitive channels: opening and closing]].<br /> | *'''MthK''' is a calcium-dependent potassium channel from ''Methanobacterium thermoautrophicum''<ref>PMID:16735753</ref>.<br /> | ||
'''Voltage-Dependent Calcium Channels''' (VDCC) allow calcium ions to enter the cell resulting in muscle contraction, neuron excitation or hormone release. VDCC are composed of several subunits and are named as a Cav gene product<ref>PMID:16096350</ref>. | *'''MscL''' and '''MscS''' are large- and small-conductance mechanosensitive channels which protect bacteria from osmotic shock by allowing ions to flow across the cell membrane<ref>PMID:12046893</ref>.<br /> | ||
See:<br /> | |||
[[Mechanosensitive channels: opening and closing]].<br /> | |||
*'''Voltage-Dependent Calcium Channels''' (VDCC) allow calcium ions to enter the cell resulting in muscle contraction, neuron excitation or hormone release. VDCC are composed of several subunits and are named as a Cav gene product<ref>PMID:16096350</ref>. <br /> | |||
See:<br /> | |||
[[Voltage-gated calcium channels]].<br /> | |||
[[Voltage-gated calcium channel Cav1.1 complex]].<br /> | |||
*'''Voltage-gated sodium (Nav) channels''' - see: | |||
*[[Bupivacaine]] | |||
*[[Carbamazepine]] | |||
There are also '''Voltage-Dependent Anion Channels''' (VDAC)<ref>PMID:16787253</ref>.<br /> | There are also '''Voltage-Dependent Anion Channels''' (VDAC)<ref>PMID:16787253</ref>.<br /> | ||
'''Chloride ion channels''' (ClCh) are involved in maintaining pH, volume homeostasis and more. The anti-parasitic drug [[Ivermectin]] binds to glutamate-gated chloride channels. | *'''Chloride ion channels''' (ClCh) are involved in maintaining pH, volume homeostasis and more. The anti-parasitic drug [[Ivermectin]] binds to glutamate-gated chloride channels.<br /> | ||
'''Ligand-Gated Ion Channels''' (LGIC) open or close when binding a ligand like a neurotransmitter<ref>PMID:15288758</ref>.<br /> | See:<br /> | ||
'''Cyclic Nucleotide-Gated channels''' (CNGC) conduct cations upon binding of cAMP or cGMP<ref>PMID:12087135</ref>.<br /> | [[Chloride Ion Channel]]<br /> | ||
'''Acid-Sensitive channels''' (ASC) conduct cations upon binding of acid<ref>PMID:19655111</ref>.<br /> | [[User:Laura Fountain/Chloride Ion Channel]]<br /> | ||
'''Glycerol facilitator''' (GlpF) is a protein channel which transports glycerol across the cell membrane of ''E. coli''<ref>PMID:12948772</ref>.<br /> | [[Chloride Intracellular Channel Protein 2]]<br /> | ||
*'''Calcium-activated chloride channel''' or '''anoctamin''' or '''scramblase''' or '''TMEM16''' are important in cell volume regulation and malignancy<ref>PMID:21607626</ref>.<br /> | |||
*'''Bestrophin''' is another type of '''Calcium-activated chloride channel'''<ref>PMID:22183384</ref><br /> | |||
*'''Ligand-Gated Ion Channels''' (LGIC) open or close when binding a ligand like a neurotransmitter<ref>PMID:15288758</ref>.<br /> | |||
See [[Journal:Acta_Cryst_D:S205979832000772X|Structural evidence for mono- and di-carboxylates binding at pharmacologically relevant extracellular sites of a pentameric ligand gated ion channel]] <ref>doi 10.1107/S205979832000772X</ref> | |||
*'''Cyclic Nucleotide-Gated channels''' (CNGC) conduct cations upon binding of cAMP or cGMP<ref>PMID:12087135</ref>.<br /> | |||
*'''Acid-Sensitive channels''' (ASC) conduct cations upon binding of acid<ref>PMID:19655111</ref>.<br /> | |||
*'''Transient receptor potential cation channel''' (TRP) superfamily consists of 6 subfamilies: canonical, melastatin-related, ankyrin, mucolipin, mucolipidosis, polycystic and vanilloid (TRPV) which is heat-sensitive <ref>PMID:15288758</ref>. For details see [[Transient Receptor Potential Cation Channel Subfamily V Member 1 (TRPV1)]].<br /> | |||
*'''Glycerol facilitator''' (GlpF) is a protein channel which transports glycerol across the cell membrane of ''E. coli''<ref>PMID:12948772</ref>.<br /> | |||
Other ion channel proteins are the aquaporins, annexin V, gramicidin, antiamoebin, trichotoxin, peptaibol and the glutamate receptor. Specific details in:<br /> | Other ion channel proteins are the aquaporins, annexin V, gramicidin, antiamoebin, trichotoxin, peptaibol and the glutamate receptor. Specific details in:<br /> | ||
*[[Proton Channels]], <br /> | *[[Proton Channels]], <br /> | ||
| Line 28: | Line 48: | ||
*[[5-hydroxytryptamine receptor#Structural highlights/Specific Function of 5-HT3|5-HT3 receptor]] | *[[5-hydroxytryptamine receptor#Structural highlights/Specific Function of 5-HT3|5-HT3 receptor]] | ||
== Classification == | == Classification == | ||
TCDB, the most sophisticated classification of transport proteins to date, classify ion channels as a heterogenous subset of all '''α-type channels''', whose singular property is to consist mainly of [[alpha helix|α-helices]] that span the membrane. They are distinct in this from the beta-barrel [[porins]] and the [[pore-forming toxins]], as well as from non-ribosomally synthesized channels like [[gramicidin]], | TCDB, the most sophisticated classification of transport proteins to date, classify ion channels as a heterogenous subset of all '''α-type channels''', whose singular property is to consist mainly of [[alpha helix|α-helices]] that span the membrane. They are distinct in this from the beta-barrel [[porins]] and the [[pore-forming toxins]], as well as from non-ribosomally synthesized channels like [[gramicidin]], polyglutamine or digitoxin. All these proteins are '''passive''' transport proteins. | ||
== Disease == | == Disease == | ||
Mutations in sodium channel are involved in arrhythmia<ref>PMID:19377496</ref>, epilepsy<ref>PMID:16075041</ref>, Brugada syndrome and cardiac conduction disease<ref>PMID:18464934</ref>. Many diseases are related to voltage-gated sodium, potassium, chloride, acetylcholine and glycine ion channels<ref>PMID:11310970</ref>. | Mutations in sodium channel are involved in arrhythmia<ref>PMID:19377496</ref>, epilepsy<ref>PMID:16075041</ref>, Brugada syndrome and cardiac conduction disease<ref>PMID:18464934</ref>. Many diseases are related to voltage-gated sodium, potassium, chloride, acetylcholine and glycine ion channels<ref>PMID:11310970</ref>. Mutations in several members of the calcium-activated chloride channels or anoctamin are liked to several diseases: ano-1 to cancer, ano-5 to muscular dystrophy, ano-10 to ataxia and ano-6 to Scott syndrome<ref>PMID:21642943</ref><br /> Mutations in bestrophin are associated with macular dystrophy<ref>PMID:24328569</ref>.<br />[[Amiodarone]] and [[Amlodipine]] are voltage-gated calcium channel blockers used in treatment of cardiac dysrhythmias. | ||
==Additional Resources== | ==Additional Resources== | ||