Calcium channel, voltage-dependent, P/Q type, alpha 1A subunit
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols  ; APCA; BI; CACNL1A4; CAV2.1; EA2; FHM; HPCA; MHP; MHP1; SCA6
External IDs IUPHAR: ChEMBL: GeneCards:
RNA expression pattern
Species Human Mouse
RefSeq (mRNA)
RefSeq (protein)
Location (UCSC)
PubMed search

The Cav2.1 P/Q voltage-dependent calcium channel is encoded by the CACNA1A gene.

Voltage-dependent calcium channels mediate the entry of calcium ions into excitable cells, and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, and gene expression. Calcium channels are multisubunit complexes composed of alpha-1, beta, alpha-2/delta, and gamma subunits. The channel activity is directed by the pore-forming alpha-1 subunit, whereas, the others act as auxiliary subunits regulating this activity. The distinctive properties of the calcium channel types are related primarily to the expression of a variety of alpha-1 isoforms, alpha-1A, B, C, D, E, and S. This gene encodes the alpha-1A subunit, which is predominantly expressed in neuronal tissue. Mutations in this gene are associated with 2 neurologic disorders, familial hemiplegic migraine and episodic ataxia 2. This gene also exhibits polymorphic variation due to (CAG)n-repeats. Multiple transcript variants have been described, however, the full-length nature of not all is known. In one set of transcript variants, the (CAG)n-repeats occur in the 3' UTR, and are not associated with any disease. But in another set of variants, an insertion extends the coding region to include the (CAG)n-repeats which encode a polyglutamine tract. Expansion of the (CAG)n-repeats from the normal 4-16 to 21-28 in the coding region is associated with spinocerebellar ataxia 6.[1]


  • Interactions 1
  • References 2
  • Further reading 3
  • External links 4


Cav2.1 has been shown to interact with CACNB4.[2][3]


  1. ^ "Entrez Gene: CACNA1A calcium channel, voltage-dependent, P/Q type, alpha 1A subunit". 
  2. ^ Walker, D; Bichet D; Campbell K P; De Waard M (Jan 1998). "A beta 4 isoform-specific interaction site in the carboxyl-terminal region of the voltage-dependent Ca2+ channel alpha 1A subunit". J. Biol. Chem. (UNITED STATES) 273 (4): 2361–2367.  
  3. ^ Walker, D; Bichet D; Geib S; Mori E; Cornet V; Snutch T P; Mori Y; De Waard M (Apr 1999). "A new beta subtype-specific interaction in alpha1A subunit controls P/Q-type Ca2+ channel activation". J. Biol. Chem. (UNITED STATES) 274 (18): 12383–12390.  

Further reading

  • Terwindt G, Kors E, Haan J et al. (2002). "Mutation analysis of the CACNA1A calcium channel subunit gene in 27 patients with sporadic hemiplegic migraine". Arch. Neurol. 59 (6): 1016–1018.  
  • Catterall WA, Perez-Reyes E, Snutch TP, Striessnig J (2006). "International Union of Pharmacology. XLVIII. Nomenclature and structure-function relationships of voltage-gated calcium channels". Pharmacol. Rev. 57 (4): 411–425.  
  • Perez-Reyes E, Castellano A, Kim HS et al. (1992). "Cloning and expression of a cardiac/brain beta subunit of the L-type calcium channel". J. Biol. Chem. 267 (3): 1792–7.  
  • Barry EL, Viglione MP, Kim YI, Froehner SC (1995). "Expression and antibody inhibition of P-type calcium channels in human small-cell lung carcinoma cells". J. Neurosci. 15 (1 Pt 1): 274–83.  
  • Joutel A, Bousser MG, Biousse V et al. (1993). "A gene for familial hemiplegic migraine maps to chromosome 19". Nat. Genet. 5 (1): 40–45.  
  • Margolis RL, Breschel TS, Li SH et al. (1996). "Characterization of cDNA clones containing CCA trinucleotide repeats derived from human brain". Somat. Cell Mol. Genet. 21 (4): 279–284.  
  • Rettig J, Sheng ZH, Kim DK et al. (1996). "Isoform-specific interaction of the alpha1A subunits of brain Ca2+ channels with the presynaptic proteins syntaxin and SNAP-25". Proc. Natl. Acad. Sci. U.S.A. 93 (14): 7363–7368.  
  • Diriong S, Lory P, Williams ME et al. (1997). "Chromosomal localization of the human genes for alpha 1A, alpha 1B, and alpha 1E voltage-dependent Ca2+ channel subunits". Genomics 30 (3): 605–609.  
  • Ophoff RA, Terwindt GM, Vergouwe MN et al. (1996). "Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+ channel gene CACNL1A4". Cell 87 (3): 543–552.  
  • Zhuchenko O, Bailey J, Bonnen P et al. (1997). "Autosomal dominant cerebellar ataxia (SCA6) associated with small polyglutamine expansions in the alpha 1A-voltage-dependent calcium channel". Nat. Genet. 15 (1): 62–69.  
  • De Waard M, Liu H, Walker D et al. (1997). "Direct binding of G-protein betagamma complex to voltage-dependent calcium channels". Nature 385 (6615): 446–450.  
  • Qin N, Platano D, Olcese R et al. (1997). "Direct interaction of gbetagamma with a C-terminal gbetagamma-binding domain of the Ca2+ channel alpha1 subunit is responsible for channel inhibition by G protein-coupled receptors". Proc. Natl. Acad. Sci. U.S.A. 94 (16): 8866–8871.  
  • Riess O, Schöls L, Bottger H et al. (1997). "SCA6 is caused by moderate CAG expansion in the alpha1A-voltage-dependent calcium channel gene". Hum. Mol. Genet. 6 (8): 1289–1293.  
  • Jodice C, Mantuano E, Veneziano L et al. (1998). "Episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6) due to CAG repeat expansion in the CACNA1A gene on chromosome 19p". Hum. Mol. Genet. 6 (11): 1973–1978.  
  • Charvin N, L'evêque C, Walker D et al. (1997). "Direct interaction of the calcium sensor protein synaptotagmin I with a cytoplasmic domain of the alpha1A subunit of the P/Q-type calcium channel". EMBO J. 16 (15): 4591–4596.  
  • Ishikawa K, Tanaka H, Saito M et al. (1997). "Japanese families with autosomal dominant pure cerebellar ataxia map to chromosome 19p13.1-p13.2 and are strongly associated with mild CAG expansions in the spinocerebellar ataxia type 6 gene in chromosome 19p13.1". Am. J. Hum. Genet. 61 (2): 336–346.  
  • Walker D, Bichet D, Campbell KP, De Waard M (1998). "A beta 4 isoform-specific interaction site in the carboxyl-terminal region of the voltage-dependent Ca2+ channel alpha 1A subunit". J. Biol. Chem. 273 (4): 2361–2367.  
  • Yue Q, Jen JC, Thwe MM et al. (1998). "De novo mutation in CACNA1A caused acetazolamide-responsive episodic ataxia". Am. J. Med. Genet. 77 (4): 298–301.  
  • Hans M, Urrutia A, Deal C et al. (1999). "Structural elements in domain IV that influence biophysical and pharmacological properties of human alpha1A-containing high-voltage-activated calcium channels". Biophys. J. 76 (3): 1384–1400.  
  • Walker D, Bichet D, Geib S et al. (1999). "A new beta subtype-specific interaction in alpha1A subunit controls P/Q-type Ca2+ channel activation". J. Biol. Chem. 274 (18): 12383–12390.  

External links

  • Jen, Joanna C (2009-09-08). Familial Hemiplegic Migraine. NBK1388.  In Pagon RA, Bird TD, Dolan CR, et al., ed. (1993–). GeneReviews™ [Internet]. Seattle WA: University of Washington, Seattle. 
  • Spacey, Sian (2011-12-08). Episodic Ataxia Type 2. NBK1501.  In GeneReviews
  • Gomez, Christopher M (2013-07-18). Spinocerebellar Ataxia Type 6. NBK1140.  In GeneReviews