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 LIN7B, MAGI1 and GOPC (By similarity). Interacts with DLG4 and ASIC2. Interacts with STOM; this regulates channel activity. Homotrimeric ASIC3 and ASIC3-containing heterotrimers interact with the cono-RFamide CNF-Tx1.1, and probably CNF-Tx1.2 and CNF-Tx1.3 (AC P0DL71) (PubMed:28396446). In part cytoplasmic in cochlea cells (By similarity). Cell surface expression may be stabilized by interaction with LIN7B and cytoplasmic retention by interaction with DLG4. Expressed in sciatic nerve and dorsal root ganglion (at protein level). Expressed in sensory neurons of dorsal root ganglion. Expressed in Golgi interneurons in the granular layer. Also found in superior cervical ganglia, spinal cord and brain stem. Expression is first detected at E15.5. Strongly expressed perinatally. Transcriptionally regulated by the proinflammatory mediators nerve growth factor, serotonin, interleukin-1 and bradykinin. Up-regulation upon tissue inflammation is abolished by anti-inflammatory drugs. The PDZ domain-binding motif is involved in interaction with LIN7A, GOPC and MAGI1/BAIAP1. Phosphorylated by PKA (By similarity). 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/ACCN3 channel. Potentiated by FMRFamide-related neuropeptides (By similarity). Sensitized and potentiated by NPFF and NPSF. Regulated by lactate and Ca(2+). Specifically inhibited by APETx2, a sea anemone toxin. Inhibited by anti-inflammatory drugs like salicylic acid. Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. ASIC3 subfamily.