Protein Details: Acid-sensing ion channel 1

Protein ID

ICDB_Pro_0624

Protein Name

Acid-sensing ion channel 1

Gene Name

Asic1; Accn2; Bnac2

Organism

Rattus norvegicus (Rat)

Length

526 amino acids

AlphaFoldDB

AF-P55926-F1-model_v4.pdb

Function

Proton-gated sodium channel; it is activated by a drop of the extracellular pH and then becomes rapidly desensitized. Generates a biphasic current with a fast inactivating and a slow sustained phase. Has high selectivity for sodium ions and can also transport lithium ions with high efficiency. Can also transport potassium ions; but with lower efficiency. It is nearly impermeable to the larger rubidium and cesium ions. Isoform 3 discrimates stronger than isoform 1 between monovalent cations. Isoform 3 can flux Ca(2+) while isoform 1 cannot. Heteromeric channels composed of isoform 2 and isoform 3 are active but have a lower pH-sensitivity. Mediates glutamate-independent Ca(2+) entry into neurons upon acidosis. This Ca(2+) overloading is toxic for cortical neurons and may be in part responsible for ischemic brain injury. Heteromeric channel assembly seems to modulate channel properties.

Sequence

MELKTEEEEVGGVQPVSIQAFASSSTLHGLAHIFSYERLSLKRALWALCFLGSLAVLLCVCTERVQYYFCYHHVTKLDEVAASQLTFPAVTLCNLNEFRFSQVSKNDLYHAGELLALLNNRYEIPDTQMADEKQLEILQDKANFRSFKPKPFNMREFYDRAGHDIRDMLLSCHFRGEACSAEDFKVVFTRYGKCYTFNSGQDGRPRLKTMKGGTGNGLEIMLDIQQDEYLPVWGETDETSFEAGIKVQIHSQDEPPFIDQLGFGVAPGFQTFVSCQEQRLIYLPSPWGTCNAVTMDSDFFDSYSITACRIDCETRYLVENCNCRMVHMPGDAPYCTPEQYKECADPALDFLVEKDQEYCVCEMPCNLTRYGKELSMVKIPSKASAKYLAKKFNKSEQYIGENILVLDIFFEVLNYETIEQKKAYEIAGLLGDIGGQMGLFIGASILTVLELFDYAYEVIKHRLCRRGKCQKEAKRSSADKGVALSLDDVKRHNPCESLRGHPAGMTYAANILPHHPARGTFEDFTC

PDB Structures

Ligand Binding

1. DICL_CP

2. DICL_Pep

Binding Site

SITE 71: "Important for channel gating"; SITE 79: "Important for channel desensitizing"; SITE 175: "Important residue in interaction with the spider venom Pi-theraphotoxin-Hm3a; which can explain functional difference between ASIC1a and ASIC1b";SITE 177: "Important residue for interaction with the spider venom Pi-theraphotoxin-Hm3a; which can explain functional difference between ASIC1a and ASIC1b";SITE 287: "Important for channel gating"; SITE 349: "Important for interaction with the snake venom mambalgin-2"; SITE 350: "Important for interaction with the snake venom mambalgin-1 and mambalgin-2 toxins; probably binds to its residue L-53; Important for interaction with the spider venom Pi-hexatoxin-Hi1a and psalmotoxin-1"

Disease

Location

Expressed in dorsal root ganglia and sciatic nerve (at protein level). Widely distributed throughout the brain. Expressed in olfactory bulb; neo and allocortical regions; dentate granule cells; pyramidal cells of CA1-CA3 subfields of the hippocampal formation; habenula; basolateral amygdaloid nuclei; and in the Purkinje and granule cells of the cerebellum. Expressed in olfactory bulb; neo and allocortical regions; dentate granule cells; pyramidal cells of CA1-CA3 subfields of the hippocampal formation; habenula; basolateral amygdaloid nuclei; and in the Purkinje and granule cells of the cerebellum. Expressed in olfactory bulb; neo and allocortical regions; dentate granule cells; pyramidal cells of CA1-CA3 subfields of the hippocampal formation; habenula; basolateral amygdaloid nuclei; and in the Purkinje and granule cells of the cerebellum. Diffusely detected over most other regions of the basal ganglia; including thalamic nuclei; substantia nigra; striatum and globus pallidus; hypothalamus; midbrain; pons; medulla and choroid plexus. Isoform 3 is expressed only in dorsal root ganglion (DRG) while isoform 1 is expressed in DRG; spinal chord; trigeminal ganglia and the trigeminal mesencephalic nucleus.

DOI ID

10.1038/386173a0; 10.1073/pnas.95.17.10240; 10.1074/jbc.m104030200; 10.1097/00001756-200109170-00022; 10.1074/jbc.272.46.28819; 10.1074/jbc.m003643200; 10.1016/s0896-6273(00)81144-7; 10.1523/jneurosci.21-20-08026.2001; 10.1074/jbc.m205877200; 10.1073/pnas.042688199; 10.1074/jbc.m304441200; 10.1016/j.cell.2004.08.026; 10.1085/jgp.200308973; 10.1038/nature11494; 10.1016/j.toxicon.2013.04.008; 10.1002/anie.201308898; 10.1074/jbc.m114.561076; 10.1111/bph.13267; 10.1074/jbc.m115.702373; 10.1016/j.neuropharm.2017.03.020; 10.1073/pnas.1614728114

RefSeq

NP_077068.1 [P55926-1]; XP_006257440.1 [P55926-3]

Feature