ASIC1 Isoform 2 and isoform 3 function as proton-gated sodium channels; they are activated by a drop of the extracellular pH and then become rapidly desensitized. The channel 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. Isoform 2 can also transport potassium, but with lower efficiency. It is nearly impermeable to the larger rubidium and cesium ions. Isoform 3 can also transport calcium ions. 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. Functions as a postsynaptic proton receptor that influences intracellular Ca(2+) concentration and calmodulin-dependent protein kinase II phosphorylation and thereby the density of dendritic spines. Modulates activity in the circuits underlying innate fear. Isoform 1 does not display proton-gated cation channel activity. Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. ASIC1 subfamily. Expressed in most or all neurons. 3 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Channel, cation; Membrane protein, integral; Membrane protein, multi-pass; Transporter; Transporter, ion channel
Chromosomal Location of Human Ortholog: 7q36
Cellular Component:  cell surface; Golgi apparatus; integral component of membrane; integral component of plasma membrane; plasma membrane; synapse
Molecular Function:  acid-sensing ion channel activity; cation channel activity; ion channel activity; ion gated channel activity; ligand-gated sodium channel activity
Biological Process:  associative learning; behavioral fear response; calcium ion transmembrane transport; cation transport; cellular response to pH; ion transmembrane transport; memory; negative regulation of neurotransmitter secretion; protein homotrimerization; regulation of membrane potential; response to acidic pH; response to amphetamine; sensory perception of pain; sensory perception of sour taste; sodium ion transmembrane transport
Reference #:  P55926 (UniProtKB)
Alt. Names/Synonyms: Accn2; Acid-sensing ion channel 1; Amiloride-sensitive cation channel 2, neuronal; ASIC1; BNaC2; Brain sodium channel 2; proton gated cation channel ASIC1
Gene Symbols: Accn2
Molecular weight: 59,641 Da
Basal Isoelectric point: 5.38  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  STRING  |  Reactome  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene