Ion channels: Difference between revisions

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[[Ion channels]] are membrane proteins that catalyze the passive transport of ions through the cell membrane. Most ion channels are specific to an ion, like the [[natrium channels]], or the [[chloride channels]]. Some, like the [[TRP channels]], let through a bunch of cations. Another property of ion channels is that they can be either driven by voltage or 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).
[[Ion channels]] are membrane proteins that catalyze the passive transport of ions through the cell membrane. Most ion channels are specific to an ion, like the [[natrium channels]], or the [[chloride channels]]. Some, like the [[TRP channels]], let through a bunch of cations. Another property of ion channels is that they can be either driven by voltage or 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).
MthK is a calcium-dependent potassium channel from Methanobacterium thermoautrophicum.  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. Voltage-Dependent Calcium Channels (VDCC) allow Ca 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. Finally, ion channels are the fastest of all membrane transporters, with 10<sup>6</sup> to 10<sup>8</sup> transported units per second versus 10^2 to 10^4 molecules per second for porters/carriers, or 10<sup>0</sup> to 10<sup>3</sup> for ATP-driven pumps. The images at the left and at the right correspond to one representative ion channel structure, ''i.e.'' crystal structure of voltage-dependent potassium channel from ''Rattus norvegicus'' ([[1qrq]]).
MthK is a calcium-dependent potassium channel from Methanobacterium thermoautrophicum.  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. Voltage-Dependent Calcium Channels (VDCC) allow Ca 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. Finally, ion channels are the fastest of all membrane transporters, with 10<sup>6</sup> to 10<sup>8</sup> transported units per second versus 10<sup>2</sup> to 10<sup>4</sup> molecules per second for porters/carriers, or 10<sup>0</sup> to 10<sup>3</sup> for ATP-driven pumps. The images at the left and at the right correspond to one representative ion channel structure, ''i.e.'' crystal structure of voltage-dependent potassium channel from ''Rattus norvegicus'' ([[1qrq]]).


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* the [[voltage-dependent calcium channel]] from ''Rattus norvegicus'' (L-type: [[1t0h]], [[1t0j]], [[1vyt]], [[1vyu]], [[1vyv]], [[2vay]], [[3bxk]], R-type: [[3bxl]])
* the [[voltage-dependent calcium channel]] from ''Rattus norvegicus'' (L-type: [[1t0h]], [[1t0j]], [[1vyt]], [[1vyu]], [[1vyv]], [[2vay]], [[3bxk]], R-type: [[3bxl]])
* the [[voltage-gated potassium channel]] KcsA from ''Streptomyces lividans'' and ''Mus musculus'' with the structures [[1bl8]], [[1k4c]], [[1jq2]], [[1k4d]], [[2bob]], [[2boc]], [[2hg5]],[[2h8p]], [[2hfe]], [[2itc]], [[2itd]], [[2k1e]], [[2nlj]]
* the [[voltage-gated potassium channel]] KcsA from ''Streptomyces lividans'' and ''Mus musculus'' with the structures [[1bl8]], [[1k4c]], [[1jq2]], [[1k4d]], [[2bob]], [[2boc]], [[2hg5]],[[2h8p]], [[2hfe]], [[2itc]], [[2itd]], [[2k1e]], [[2nlj]]
* the [[voltage-gated potassium channel]] K<sub>v</sub>AP from ''Aeropyrum pernix'' ([[1orq]], [[2a0l]]), and human K<sub>v</sub>7 ([[2ovc]], [[3bj4]])
* the [[voltage-gated potassium channel]] K<sub>AP</sub> from ''Aeropyrum pernix'' ([[1orq]], [[2a0l]]), and human K<sub>7</sub> ([[2ovc]], [[3bj4]])
* the [[voltage-gated sodium channel]] Na<sub>v</sub>1.2 ([[1byy]], [[2kav]]) and Na<sub>v</sub>1.5 ([[2kbi]])
* the [[voltage-gated sodium channel]] Na<sub>1.2</sub> ([[1byy]], [[2kav]]) and Na<sub>1.5</sub> ([[2kbi]])
* the [[ligand-gated ion channel]] that is the [[Glutamate receptor (GluA2)|glutamate receptor]] from ''Rattus norvegicus'' ([[Glutamate receptor (GluA2)|3kg2]])
* the [[ligand-gated ion channel]] that is the [[Glutamate receptor (GluA2)|glutamate receptor]] from ''Rattus norvegicus'' ([[Glutamate receptor (GluA2)|3kg2]])
* the [[calcium-gated potassium channel mthK]] from ''Methanobacterium thermoautotrophicum'' ([[1lnq]], [[2fy8]])
* the [[calcium-gated potassium channel mthK]] from ''Methanobacterium thermoautotrophicum'' ([[1lnq]], [[2fy8]])
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* [[2ahz]] – BcKCh+K
* [[2ahz]] – BcKCh+K
* [[2pnv]] – rKCh leucine zipper domain SKCa – from ''Rattus norvegicus''
* [[2pnv]] – rKCh leucine zipper domain SKCa – from ''Rattus norvegicus''
* [[2nz0]] – hKCh Kv4.3 N-terminal+KV channel interacting protein 1 – human
* [[2nz0]] – hKCh Kv4.3 N-terminal+KV channel interacting protein 1 – ''Homo sapiens''
* [[2i2r]] - rKCh Kv4.3 N-terminal+KV channel interacting protein 1
* [[2i2r]] - rKCh Kv4.3 N-terminal+KV channel interacting protein 1
* [[1s6c]] - rKCh Kv4.2 N-terminal+KV channel interacting protein 1
* [[1s6c]] - rKCh Kv4.2 N-terminal+KV channel interacting protein 1

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Ralf Stephan, Ilan Samish, Eric Martz, Wayne Decatur, Alexander Berchansky, Michal Harel, David Canner, Jaime Prilusky, Shelly Livne