Ca channel

[Itoero]

A calcium channel is an ion channel which shows selective permeability to calcium ions. What is the role of the Ca ions?

According to this paper deranged Ca(2+) signaling may play an important role in SCA3 pathology . SCA 3 is called Machado joseph disease...I have SCA7.

https://www.ncbi.nlm.nih.gov/pubmed/19036964

[Endy0816]

Quote

The concentration of calcium (Ca2+ ions) is normally several thousand times higher outside the cell than inside. Activation of particular VGCCs allows Ca2+ to rush into the cell, which, depending on the cell type, results in activation of calcium-sensitive potassium channels, muscular contraction,[4] excitation of neurons, up-regulation of gene expression, or release of hormones or neurotransmitters.

https://en.m.wikipedia.org/wiki/Voltage-gated_calcium_channel

[BabcockHall]

Calcium ions are one member of the class of chemical species called "second messengers," which respond to hormones, the first messengers.  Calcium ions activate protein kinase C, among many other effects.  My answer is intended to be very general.

Edited March 16, 2018 by BabcockHall
added last sentence.