Protein Domain : IPR008053

Type:  Family Name:  Voltage gated sodium channel, alpha-5 subunit
Description:  Voltage-dependent sodium channels are transmembrane (TM) proteins responsible for the depolarising phase of the action potential in mostelectrically excitable cells []. They may exist in 3 states []: theresting state, where the channel is closed; the activated state, where the channel is open; and the inactivated state, where the channel is closedand refractory to opening. Several different structurally and functionally distinct isoforms are found in mammals, coded for by a multigene family, these being responsible for the different types of sodium ion currentsfound in excitable tissues. The structure of sodium channels is based on 4 internal repeats of a 6-helix bundle [] (in which 5 of the membrane-spanning segments are hydrophobic andthe 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 aconformational change. This model [] contrastswith another [], in which the TM segments are juxtaposedoctagonally. The basic structural motif (the 6-helix bundle) is also found in potassium and calcium channel alpha subunits.The SCN5A gene encodes the NaH1 channel and is expressed in cardiac muscle, foetal skeletal muscle and denervated adult skeletal muscle. Mutationsin the SCN5A gene affect the function of NaH1 channels in the heart and are one of the three causes of Long QT syndrome, an inherited cardiac arrhythmiathat can cause abrupt loss of consciousness, seizures and sudden death []; it is also associated with Brugada syndrome [] and conduction systemdisease [].This entry represents the alpha 5 subunits and distinguishes them from other members of the voltage-gated Na+ channel superfamily. For entries containing other members of this superfamily see , , . Short Name:  Na_channel_a5su

0 Child Features

3 Contains

DB identifier Type Name
IPR005821 Domain Ion transport domain
IPR000048 Binding_site IQ motif, EF-hand binding site
IPR010526 Domain Sodium ion transport-associated

2 Cross Referencess

Identifier
PTHR10037:SF178
PR01666

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0005248 IPR008053
GO:0006814 IPR008053
GO:0001518 IPR008053

3 Ontology Annotations

GO Term Gene Name
GO:0005248 IPR008053
GO:0006814 IPR008053
GO:0001518 IPR008053

1 Parent Features

DB identifier Type Name
IPR001696 Family Voltage gated sodium channel, alpha subunit

0 Proteins

6 Publications

First Author Title Year Journal Volume Pages PubMed ID
            1323284
            6209577
            1317577
            7889574
            10358800
            10471492