Enables several functions, including ATP binding activity; extracellularly ATP-gated cation channel activity; and lipopolysaccharide binding activity. Involved in negative regulation of cell volume and sensory perception of pain. Acts upstream of or within several processes, including organophosphate ester transport; positive regulation of cytokine production; and positive regulation of secretion. Located in several cellular components, including external side of plasma membrane; neuromuscular junction; and neuronal cell body. Is integral component of plasma membrane. Is expressed in brain; heart; and metanephros. Orthologous to human P2RX7 (purinergic receptor P2X 7). [provided by Alliance of Genome Resources, Apr 2022]