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Na+ channel protein type 9 subunit alpha; Na+ channel protein type IX subunit alpha; voltage-gated Na+ channel subunit alpha Nav1.7; neuroendocrine Na+ channel; hNE-Na; peripheral Na+ channel 1 (SCN9A, NENA, PN1)

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 - tetrodotoxin-sensitive Na+ channel isoform - plays a role in pain mechanisms, especially in the development of inflammatory pain (putative) - ubiquitinated by NEDD4L; which may promote its endocytosis - does not seem to be ubiquitinated by NEDD4 (putative) - the Na+ channel consists of a large polypeptide & 2-3 smaller ones interacts with NEDD4 & NEDD4L (putative) Structure: - large polypeptide contains 4 internal repeats, each with 5 hydrophobic segments (S1,S2,S3,S5,S6) & 1 positively charged segment (S4). - segment S4 is probably the voltage-sensor & 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 - in neurite terminals (putative) Alternative splicing: named isoforms=3 Expression: - expressed strongly in dorsal root ganglion, with only minor levels elsewhere in the body - expressed in smooth muscle cells, MTC cell line & C-cell carcinoma - isoform 1 is expressed preferentially in the central & peripheral nervous system while isoform 2 is expressed preferentially in the dorsal root ganglion Pathology: - defects in SCN9A are the cause of a) primary erythromelalgia b) autosomal recessive congenital indifference to pain c) paroxysmal extreme pain disorder

Related

voltage-dependent Na+ channel

General

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

Properties

SIZE: entity length = 1988 aa MW = 226 kD COMPARTMENT: cellular membrane MOTIF: consensus repeat {121-405} MOTIF: transmembrane domain {122-145} transmembrane domain {154-173} transmembrane domain {187-205} N-glycosylation site {N209} transmembrane domain {212-231} transmembrane domain {248-271} N-glycosylation site {N283} transmembrane domain {379-404} consensus repeat {738-969} MOTIF: transmembrane domain {739-763} transmembrane domain {775-798} transmembrane domain {807-826} transmembrane domain {833-852} transmembrane domain {869-889} transmembrane domain {943-968} consensus repeat {1187-1458} MOTIF: transmembrane domain {1188-1211} transmembrane domain {1225-1250} transmembrane domain {1257-1278} transmembrane domain {1283-1304} transmembrane domain {1324-1351} N-glycosylation site {N1352} N-glycosylation site {N1366} N-glycosylation site {N1375} Tyr phosphorylation site {Y1413} Ser phosphorylation site {S1418} transmembrane domain {1431-1457} consensus repeat {1510-1761} MOTIF: transmembrane domain {1511-1534} transmembrane domain {1546-1569} transmembrane domain {1576-1599} transmembrane domain {1610-1631} transmembrane domain {1647-1669} transmembrane domain {1736-1760} IQ motif {1889-1918}

Database Correlations

OMIM correlations MORBIDMAP 603415 UniProt Q15858 PFAM correlations Entrez Gene 6335 Kegg hsa:6335

References

  1. UniProt :accession Q15858
  2. GeneReviews https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCN9A
  3. Wikipedia; Note: SCN9A entry http://en.wikipedia.org/wiki/SCN9A
  4. Protein Spotlight; Silent pain - Issue 102, February 2009 http://www.expasy.org/spotlight/back_issues/sptlt102.shtml