The N-type calcium channel is a type of voltage-dependent calcium channel

Voltage-dependent calcium channel

Voltage-dependent calcium channels are a group of voltage-gated ion channels found in excitable cells with a permeability to the ion Ca2+...

. Like the others of this class, the α₁ subunit forms the pore through which calcium enters the cell and determines most of the channel's properties. The α₁ subunit is also known as the calcium channel, voltage-dependent, N type, alpha 1B subunit (CACNA1B) or Cav_2.2 which in humans is encoded by the CACNA1B gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

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Structure

In addition to the α₁ subunit, the following subunits are present in the N-type calcium channel:

• α₂δ – CACNA2D1
  CACNA2D1
  Voltage-dependent calcium channel subunit alpha-2/delta-1 is a protein that in humans is encoded by the CACNA2D1 gene.- External links :...
  
  , CACNA2D2
  CACNA2D2
  Voltage-dependent calcium channel subunit alpha2delta-2 is a protein that in humans is encoded by the CACNA2D2 gene....
  
  
• β₁ – CACNB1
  CACNB1
  Voltage-dependent L-type calcium channel subunit beta-1 is a protein that in humans is encoded by the CACNB1 gene.- External links :...
  
  
• β₃ – CACNB3
  CACNB3
  Voltage-dependent L-type calcium channel subunit beta-3 is a protein that in humans is encoded by the CACNB3 gene....
  
  
• β₄ – CACNB4
  CACNB4
  Voltage-dependent L-type calcium channel subunit beta-4 is a protein that in humans is encoded by the CACNB4 gene.- Function :This gene encodes a member of the beta subunit family, a protein in the voltage-dependent calcium channel complex...
  
  

Function

N-type ('N' for "Neural-Type" ) calcium channels are found primarily at presynaptic

Chemical synapse

Chemical synapses are specialized junctions through which neurons signal to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie...

 terminals and are involved in neurotransmitter

Neurotransmitter

Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

 release. Strong depolarization by an action potential causes these channels to open and allow influx of Ca²⁺, initiating vesicle fusion and release of stored neurotransmitter. N-type channels are blocked by ω-conotoxin

Conotoxin

A conotoxin is one of a group of neurotoxic peptides isolated from the venom of the marine cone snail, genus Conus.Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Conotoxins have a variety of mechanisms of actions, most of...

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Therapeutic Potential

Recently, blockade of the N-type calcium channel has emerged as a potential therapeutic strategy for the treatment of alcoholism

Alcoholism

Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...

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Blockers

• ω-Conotoxin
  Conotoxin
  A conotoxin is one of a group of neurotoxic peptides isolated from the venom of the marine cone snail, genus Conus.Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Conotoxins have a variety of mechanisms of actions, most of...
  
  s
• Ziconotide
• Caroverine
  Caroverine
  Caroverine is a drug used as a spasmolytic and otoneuroprotective agent in some countries. It acts as an N-type calcium channel blocker, competitive AMPA receptor antagonist, and non-competitive NMDA receptor antagonist. It also has potent antioxidant effects.- References :...
  
  
• Cilnidipine
  Cilnidipine
  Cilnidipine is a calcium channel blocker. It is sold as 'Atelec' in Japan, and as 'Cilacar' in India as 5 mg and 10 mg tablets....
  
  
• NP078585
• TROX-1
  TROX-1
  TROX-1 is a drug which acts as a potent blocker of the Cav2 type calcium channels. It was developed as a potential analgesic after the discovery that the selective Cav2.2 blocker ziconotide is an active analgesic with similar efficacy to strong opioid drugs but comparatively milder side effects...