User Visitor Login
/images/graph_sv_i.gif
English only
EPFL > FSV > BBP > Channelpedia
Ion channels
References
Reports
SEARCH IN WIKI
Logged in as a Visitor.

cacng8

calcium channel, voltage-dependent, gamma subunit 8
Synonyms: cacng8. Symbol: Cacng8

Introductions


The protein encoded by CACNG8 (also known as FLJ16240; FLJ30598) is a type I transmembrane AMPA receptor regulatory protein (TARP). TARPs regulate both trafficking and channel gating of the AMPA receptors. This gene is part of a functionally diverse eight-member protein subfamily of the PMP-22/EMP/MP20 family and is located in a cluster with two family members, a type II TARP and a calcium channel gamma subunit. The mRNA for this gene is believed to initiate translation from a non-AUG (CUG) start codon.

http://www.ncbi.nlm.nih.gov/gene/59283

Genes


Phylogenetic analysis suggests that all c subunits evolved from a single ancestral gene through tandem repeat and chromosome duplication (Burgesse [1312], Chu [1311]). Based on sequence homology and chromosomal linkage the c subunits can be divided into three clusters: (c1, c6), (c5, c7), and (c2, c3, c4, c8) (Burgesse [1312], Chu [1311]). See also the phylogenetic tree, fig.2 in Black [478].

The four c subunits identified as regulators of AMPA receptor function (c2, c3, c4, and c8; the TARPs) are widely expressed in the brain and share highly conserved sequences that are quite distinct from c1 and c6 (Arikkath [1324], Black [478]).

Cacng8 : calcium channel, voltage-dependent, gamma subunit 8

RGD ID Chromosome Position Species
628808 1 64068324-64088556 Rat
732323 7 3394459-3415366 Mouse
732322 19 54466294-54486139 Human

Transcripts


Acc No Sequence Length Source
NM_080696 NCBI
NM_133190 NCBI
NM_031895 NCBI

Ontologies


Accession Name Definition Evidence
GO:0016020 membrane Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. IEA
GO:0016021 integral to membrane Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane. IEA

Interactions


The most distinct features of the TARPs are the terminal PDZ-binding motifs overlapped with PKA phosphorylation sites. The terminal TTPV motif is known to interact with PSD-95 in the postsynaptic density and the binding is regulated by the PKA motif immediately preceding the PDZ-binding motif (Chetkovich [1325], Choi [1326]). In addition to the critical PDZ-binding motif, the C-terminal regions of the four c subunits known as the TARPs (c2, c3, c4, c8) also contain regulatory sites that control AMPA receptor targeting. (Chen [1310])

Proteins


Structures


The eight calcium channel c subunits share a predicted structure that includes four transmembrane domains with intracellular N- and C- termini (Fig. 1 in Chen [1310]). They are members of a large protein superfamily (pfam00822, a subset of the tetraspanin supergroup) that also includes claudins, proteins that are important components of tight junctions in epithelia. The c subunits share with the claudins a conserved GLW motif of unknown significance in the first extracellular loop. Chen [1310]

The cytoplasmic C-terminal regions of the TARPs (to which cacng8 = gamma8 = c8 belongs) contain a number of regulatory sites including a PDZ-binding motif. This PDZ-binding motif (TTPV) is critical for targeting AMPA receptors to the synapse. Chen [1310]

Distributions


Expressions


The four c subunits identified as regulators of AMPA receptor function (c2, c3, c4, and c8; the TARPs) are widely expressed in the brain and share highly conserved sequences that are quite distinct from c1 and c6 (Arikkath [1324], Black [478]).

Functionals


Kinetics


Models


References


[1310 : 17652770]
[1324 : 12850214]
[1322 : 12409298]
[1340 : 15174133]
[1313 : 10613843]
[1312 : 11170751]
[1311 : 11738816]
[1336 : 11927536]
[478 : 15000525]
[1326 : 11805122]
[1325 : 12122038]

Credits