Alternative titles; symbolsN-COPINEHGNC Approved Gene Symbol: CPNE6Cytogenetic location: 14q11.2 Genomic coordinates (GRCh38): 14:24,069,832-24,078,099 (from...
Alternative titles; symbols
HGNC Approved Gene Symbol: CPNE6
Cytogenetic location: 14q11.2 Genomic coordinates (GRCh38): 14:24,069,832-24,078,099 (from NCBI)
Copines are a family of calcium-dependent lipid-binding proteins that are evolutionarily conserved from Arabidopsis to Homo sapiens. Copines are composed of 2 N-terminal C2 domains (C2Ds) and a C-terminal A domain (AD). The C2Ds contain aspartate residues important for calcium and phospholipid binding (summary by Ramsey et al., 2008). See CPNE1 (604205) for background information.
▼ Cloning and Expression
Using a 2-dimensional cDNA display system, restriction landmark cDNA scanning, Nakayama et al. (1998) isolated copine VI, which they designated N-copine, from mouse and human brain cDNA libraries. The human cDNA encodes a 557-amino acid protein. Like copine I, copine VI contains 2 C2 domains in the N terminus that show greater similarity to those of PLC-gamma (see 172420) than to those of double C2 domain proteins. Northern blot analysis detected a 2.2-kb transcript in brain only.
▼ Gene Function
By in situ hybridization, Nakayama et al. (1998) demonstrated that expression of CPNE6 is upregulated by neuronal activity such as kainate stimulation. The authors suggested that CPNE6 may play a role in synaptic plasticity. In further in situ hybridization studies in mouse, Nakayama et al. (1999) demonstrated that CPNE6 is expressed exclusively in neurons of the hippocampus and in the main and accessory olfactory bulbs, where various forms of synaptic plasticity and memory formation occur. Immunohistochemical studies detected CPNE6 mainly in the cell bodies and dentrites in the neurons, suggesting that CPNE6 has a role in postsynaptic events, in contrast to the presynaptic roles of the double C2 domain proteins. A GST-fusion protein with the second C2 domain of copine VI showed calcium-dependent binding to phosphatidylserine, indicating that this domain is responsible for the calcium-dependent association of copine VI with the membrane.
The International Radiation Hybrid Mapping Consortium mapped the CPNE6 gene to chromosome 14 (stSG35445). Scott (2001) refined the location to 14q11.2 based on sequence similarity between the CPNE6 sequence (GenBank AB009288.1) and a genomic contig (GenBank NT_010062).