CACNG2/A0473

Voltage-dependent calcium channel gamma 2 (CACNG2), also known as stargazin or A0473, encodes a subunit of the L-type neuronal calcium channel.

Voltage-dependent calcium channel gamma 2 (CACNG2), also known as stargazin or A0473, encodes a subunit of the L-type neuronal calcium channel. The expression of CACNG2 is brain-specific, with enrichment in synaptic plasma membranes. The protein subunit interacts with alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits, as well as PDZ domains of DLG1/SAP97 and DLG4/PSD95. These interactions with synaptic proteins give CACNG2 an important role in synaptic trafficking, in particular targeting AMPA receptor to synapses. Moreover, CACNG2 is thought to stabilize the calcium channel in an inactivated state, thereby controlling channel properties. Homozygous mice with mutant alleles of CACNG2 show growth retardation and movement disorders including seizure phenotypes and ataxic gait. The mutant mouse also lacks functional AMPA receptors on cerebellar granule cells. Homozygous mice with mutant alleles of CACNG2 show growth retardation and movement disorders including seizure phenotypes and ataxic gait. The mutant mouse also lack functional AMPA receptors on cerebellar granule cells.