R-type calcium channel

R-type calcium channel is a type of voltage-gated calcium channel that plays a crucial role in various physiological processes. These channels are named "R" for "resistant" because they are resistant to many drugs and toxins that typically block other types of calcium channels.

Structure

The R-type calcium channel is composed of several subunits, including the main pore-forming α1 subunit and auxiliary β, α2δ, and γ subunits. The α1 subunit is encoded by the CACNA1E gene in humans. This subunit forms the pore through which calcium ions pass and determines most of the channel's properties.

Function

R-type calcium channels are involved in a variety of physiological processes. They contribute to the release of neurotransmitters at synapses, the regulation of neuronal excitability, and the modulation of gene expression. In the heart, they participate in the regulation of cardiac contractility. In the brain, they are involved in neuronal plasticity, learning, and memory.

Clinical significance

Mutations in the CACNA1E gene that encodes the α1 subunit of the R-type calcium channel can lead to various neurological disorders. For example, they have been associated with episodic ataxia type 2, a rare inherited neurological disorder characterized by periodic episodes of unsteady gait and dizziness.

Moreover, R-type calcium channels have been implicated in the pathophysiology of several neurological diseases, including Alzheimer's disease, Parkinson's disease, and epilepsy. They are also thought to play a role in chronic pain and migraine.

See also

• Voltage-gated calcium channel
• CACNA1E
• Neurotransmitter
• Neuronal plasticity