Na+ channel protein type 1 subunit alpha; Na+ channel protein type I subunit alpha; voltage-gated Na+ channel subunit alpha Nav1.1; Na+ channel protein, brain I subunit alpha (SCN1A, NAC1, SCN1)

Function

• mediates voltage-dependent Na+ permeability of excitable membranes
• assumes opened or closed conformation in response to voltage difference across membrane
• forms a Na+-selective channel through which Na+ ions may pass in accordance with their electrochemical gradient
• the Na+ channel consists of a large polypeptide & 2-3 smaller ones

Structure

• large polypeptide contains 4 internal repeats, each with 5 hydrophobic segments (S1,S2,S3,S5,S6) & one positively charged segment (S4)
• segments S4 are probably the voltage-sensors & are characterized by a series of positively charged amino acids at every third position
• belongs to the Na+ channel family
• contains 1 IQ domain

Compartment

membrane

Alternative splicing

named isoforms=2

Pathology

• defects in SCN1A are the cause of
  • generalized epilepsy with febrile seizures plus type 2
  • severe myoclonic epilepsy in infancy (Dravet syndrome)
  • intractable childhood epilepsy with generalized tonic-clonic seizures (ICEGTC)
  • familial hemiplegic migraine type 3
  • familial febrile convulsions type 3

More general terms

• transmembrane 24 protein
• voltage-dependent Na+ channel protein alpha subunit
• glycoprotein

Additional terms

• voltage-dependent Na+ channel

Database

• UniProt: http://www.uniprot.org/uniprot/P35498.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6323
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6323
• OMIM: https://mirror.omim.org/entry/182389
• OMIM: https://mirror.omim.org/entry/604233
• OMIM: https://mirror.omim.org/entry/604403
• OMIM: https://mirror.omim.org/entry/607208
• OMIM: https://mirror.omim.org/entry/609634