Cation channel with high affinity for sodium, which is gated by extracellular protons and inhibited by the diuretic amiloride. Generates a biphasic current with a fast inactivating and a slow sustained phase. In sensory neurons is proposed to mediate the pain induced by acidosis that occurs in ischemic, damaged or inflamed tissue. May be involved in hyperalgesia. May play a role in mechanoreception. Heteromeric channel assembly seems to modulate channel properties. Homotrimer or heterotrimer with other ASIC proteins (By similarity). Interacts with STOM; this regulates channel activity. Interacts with DLG4 (By similarity). Interacts with LIN7B, MAGI1/BAIAP1, GOPC and ASIC2. Cell surface expression may be stabilized by interaction with LIN7B and cytoplasmic retention by interaction with DLG4. In part cytoplasmic in cochlea cells (By similarity). Expressed by sensory neurons. Strongly expressed in brain, spinal chord, lung, lymph nodes, kidney, pituitary, heart and testis. Expressed in fetal tissues, expression increases in lung and kidney adult tissues. The PDZ domain-binding motif is involved in interaction with LIN7A, GOPC and MAGI1. Phosphorylated by PKA. Phosphorylated by PKC. In vitro, PRKCABP/PICK-1 is necessary for PKC phosphorylation and activation of a ASIC3/ACCN3-ASIC2/ASIC2b channel, but does not activate a homomeric ASIC3 channel (By similarity). Potentiated by FMRFamide-related neuropeptides. Sensitized and potentiated by NPSF. Regulated by lactate and Ca(2+). Inhibited by anti-inflammatory drugs, like salicylic acid (By similarity). Sensitized and potentiated by NPFF. Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. ASIC3 subfamily. Extended N-terminus.