| Literature References | 1. GEORGE, A.L., KNITTLE, T.J. AND TAMKUN, M.M.
Molecular cloning of an atypical voltage-gated sodium channel expressed in
human heart and uterus - Evidence for a distinct gene family.
PROC.NATL.ACAD.SCI.U.S.A. 89(11) 4893-4897 (1992).
2. NODA, M., IKEDA, T., KAYANO, T., SUZUKI, H., TAKESHIMA, H.,
KURASAKI, M., TAKAHASHI, H. AND NUMA, S.
Existence of distinct sodium channel messenger RNAs in rat brain.
NATURE 320 188-192 (1986).
3. NODA, M., SHIMIZU, S., TANABE, T., TAKAI, T., KAYANO, T., IKEDA, T.,
TAKAHASHI, H., NAKAYAMA, H., KANAOKA, Y., MINAMINO, M., KANGAWA, K.,
MATSUO, H., RAFTERY, M.A., HIROSE, T., INAYAMA, S., HAYASHIDA, H, MIYATA,
T. AND NUMA, S.
Primary structure of Electrophorus electricus sodium channel deduced from
cDNA sequence.
NATURE 312 121-127 (1984).
4. ROGART, R.B., CRIBBS, L.L., MUGLIA, L.K., KEPHART, D.D. AND KAISER, M.W.
Molecular cloning of a putative tetrodotoxin resistant rat heart Na+
channel isoform.
PROC.NATL.ACAD.SCI.U.S.A. 86(20) 8170-8174 (1989).
5. SATO, C. AND MATSUMOTO, G.
Proposed tertiary structure of the sodium channel.
BIOCHEM.BIOPHYS.RES.COMMUN. 186 1158-1167 (1992).
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| Documentation | Voltage-dependent sodium channels are transmembrane (TM) proteins
responsible for the depolarising phase of the action potential in most
electrically excitable cells [1]. They may exist in 3 states [3]: the
resting state, where the channel is closed; the activated state, where the
channel is open; and the inactivated state, where the channel is closed
and refractory to opening. Several different structurally and functionally
distinct isoforms are found in mammals, coded for by a multigene family
[4], these being responsible for the different types of sodium ion currents
found in excitable tissues.
The structure of sodium channels is based on 4 internal repeats of a
6-helix bundle [2] (in which 5 of the membrane-spanning segments are
hydrophobic and the other is positively charged), forming a 24-helical
bundle. The charged segments are believed to be localised within clusters
formed by their 5 hydrophobic neighbours: it is postulated that the charged
domain may be the voltage sensor region, possibly moving outward on
depolarisation, causing a conformational change. This model, proposed by
Noda et al. [2], contrasts with that of Sato and Matsumoto [5], in which
the TM segments are juxtaposed octagonally. The basic structural motif (the
6-helix bundle) is also found in potassium and calcium channels alpha
subunits.
NACHANNEL is a 2-element fingerprint that provides a signature for voltage-
gated Na+ channel alpha subunits. The fingerprint was derived from an
initial alignment of 34 sequences: motif 1 lies on the sixth TM domain, of
the fourth internal repeat; and motif 2 encodes a portion of the putative
cytoplasmic C-terminus. Two iterations on SPTR37_10f were required to reach
convergence, at which point a true set comprising 49 sequences was
identified.
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| Sequence Titles | CIN1_LOLBL SODIUM CHANNEL PROTEIN I, BRAIN - LOLIGO BLEEKERI (BLEEKER'S SQUID).
CIN1_RAT Sodium channel protein, brain I alpha subunit - Rattus norvegicus (Rat).
CIN2_RAT SODIUM CHANNEL PROTEIN, BRAIN II ALPHA SUBUNIT - RATTUS NORVEGICUS (RAT).
CIN3_RAT SODIUM CHANNEL PROTEIN, BRAIN III ALPHA SUBUNIT - RATTUS NORVEGICUS (RAT).
CIN4_HUMAN Sodium channel protein, skeletal muscle alpha-subunit - Homo sapiens (Human).
CIN4_RAT Sodium channel protein, skeletal muscle alpha-subunit (MU-1) - Rattus norvegicus (Rat).
CIN5_HUMAN Sodium channel protein, cardiac muscle alpha-subunit (HH1) - Homo sapiens (Human).
CIN5_RAT Sodium channel protein, cardiac muscle alpha-subunit - Rattus norvegicus (Rat).
CIN6_HUMAN SODIUM CHANNEL PROTEIN, CARDIAC AND SKELETAL MUSCLE ALPHA-SUBUNIT - HOMO SAPIENS (HUMAN).
CINA_DROME SODIUM CHANNEL PROTEIN PARA (PARALYTIC PROTEIN) - DROSOPHILA MELANOGASTER (FRUIT FLY).
CINA_ELEEL SODIUM CHANNEL PROTEIN (NA+ CHANNEL) - ELECTROPHORUS ELECTRICUS (ELECTRIC EEL).
O01306 PARA SODIUM CHANNEL - BLATTELLA GERMANICA (GERMAN COCKROACH).
O01307 PARA SODIUM CHANNEL - BLATTELLA GERMANICA (GERMAN COCKROACH).
O02037 VOLTAGE-GATED SODIUM CHANNEL HOMOLOG BDNA1 - BDELLOURA CANDIDA.
O44930 PUTATIVE VOLTAGE-GATED SODIUM CHANNEL - AIPTASIA PALLIDA.
O46669 TTX-RESISTANT SODIUM CHANNEL - CANIS FAMILIARIS (DOG).
O62604 VOLTAGE-GATED SODIUM CHANNEL ALPHA SUBUNIT - POLYORCHIS PENICILLATUS (HYDROMEDUSA).
O70611 RAT SKELETAL MUSCLE TYPE 1 VOLTAGE-GATED SODIUM CHANNEL (RSKM1) VARIANT (RSKM1) - Rattus norvegicus (Rat).
O88420 VOLTAGE-GATED SODIUM CHANNEL RPN4 - Rattus norvegicus (Rat).
O88421 VOLTAGE-GATED SODIUM CHANNEL VARIANT RPN4A - Rattus norvegicus (Rat).
O88457 VOLTAGE-GATED NA CHANNEL ALPHA SUBUNIT NAN - RATTUS NORVEGICUS (RAT).
O95788 VOLTAGE-GATED SODIUM CHANNEL ALPHA SUBUNIT - Homo sapiens (Human).
P70276 SODIUM CHANNEL, TYPE X, ALPHA POLYPEPTIDE (VOLTAGE-GATED SODIUM CHANNEL) - MUS MUSCULUS (MOUSE).
P90670 SODIUM CHANNEL ALPHA-SUBUNIT SCAP1 - APLYSIA CALIFORNICA (CALIFORNIA SEA HARE).
P97706 SODIUM CHANNEL - RATTUS NORVEGICUS (RAT).
Q14472 VOLTAGE-GATED SODIUM CHANNEL (VOLTAGE-GATED SODIUM CHANNEL SUBTYPE II) - HOMO SAPIENS (HUMAN).
Q15478 SODIUM CHANNEL ALPHA SUBUNIT - HOMO SAPIENS (HUMAN).
Q15858 SODIUM CHANNEL ALPHA SUBUNIT - HOMO SAPIENS (HUMAN).
Q17314 SODIUM CHANNEL - CYANEA CAPILLATA.
Q24528 SODIUM CHANNEL ALPHA SUBUNIT - DROSOPHILA MELANOGASTER (FRUIT FLY).
Q24529 SODIUM CHANNEL ALPHA SUBUNIT - DROSOPHILA MELANOGASTER (FRUIT FLY).
Q24530 SODIUM CHANNEL ALPHA SUBUNIT - DROSOPHILA MELANOGASTER (FRUIT FLY).
Q24531 SODIUM CHANNEL ALPHA SUBUNIT - DROSOPHILA MELANOGASTER (FRUIT FLY).
Q24532 SODIUM CHANNEL ALPHA SUBUNIT - DROSOPHILA MELANOGASTER (FRUIT FLY).
Q25150 VOLTAGE-GATED SODIUM CHANNEL - HALOCYNTHIA RORETZI (SEA SQUIRT).
Q25377 SODIUM CHANNEL - LOLIGO OPALESCENS (CALIFORNIA MARKET SQUID).
Q25439 VOLTAGE-SENSITIVE SODIUM CHANNEL - MUSCA DOMESTICA (HOUSE FLY).
Q25440 VOLTAGE-SENSITIVE SODIUM CHANNEL - MUSCA DOMESTICA (HOUSE FLY).
Q28371 SKELETAL MUSCLE SODIUM CHANNEL ALPHA-SUBUNIT - Equus caballus (Horse).
Q28644 SODIUM CHANNEL ALPHA-SUBUNIT - ORYCTOLAGUS CUNICULUS (RABBIT).
Q60858 SODIUM CHANNEL, VOLTAGE-GATED, TYPE VIII, ALPHA POLYPEPTIDE (SCN8A) - Mus musculus (Mouse).
Q62205 SODIUM CHANNEL 25 - MUS MUSCULUS (MOUSE).
Q62243 SODIUM CHANNEL - MUS MUSCULUS (MOUSE).
Q62467 SODIUM CHANNEL, VOLTAGE-GATED, TYPE VI, ALPHA POLYPEPTIDE (VOLTAGE-GATED SODIUM CHANNEL PROTEIN) - MUS MUSCULUS (MOUSE).
Q62968 SODIUM CHANNEL PN3 - RATTUS NORVEGICUS (RAT).
Q63541 SODIUM CHANNEL PROTEIN 6 - Rattus norvegicus (Rat).
Q63554 VOLATAGE-GATED SODIUM CHANNEL - RATTUS NORVEGICUS (RAT).
Q94615 VOLTAGE-SENSITIVE SODIUM CHANNEL - MUSCA DOMESTICA (HOUSE FLY).
Q9YGN7 VOLTAGE-DEPENDENT SODIUM CHANNEL - CYNOPS PYRRHOGASTER (JAPANESE COMMON NEWT).
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