Na+ channel protein type 3 subunit alpha; Na+ channel protein type III subunit alpha; voltage-gated Na+ channel subunit alpha Nav1.3; Na+ channel protein, brain III subunit alpha; voltage-gated Na+ channel subtype III (SCN3A, KIAA1356, NAC3)

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
• may be ubiquitinated by NEDD4L; which would promote its endocytosis
• the Na+ channel consists of a large polypeptide & 2-3 smaller ones
• interacts with NEDD4L

Structure

• large sequence contains 4 internal repeats, each with 5 hydrophobic segments (S1,S2,S3,S5,S6) & one positively charged segment (S4)
• segment S4 is probably the voltage-sensors & is characterized by a series of positively charged amino acids at every 3rd position
• belongs to the Na+ channel family
• contains 1 IQ domain

Compartment

membrane

Alternative splicing

named isoforms=4

More general terms

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

Additional terms

• voltage-dependent Na+ channel

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6328
• OMIM: https://mirror.omim.org/entry/182391
• UniProt: http://www.uniprot.org/uniprot/Q9NY46.html