May act as a modulatory subunit rather than a functional channel. Unlike other P2XRs members, P2RX6 does not seem to form functional homotrimers (PubMed:22378790). P2RX6 requires the presence of P2RX4 or P2RX2 to shuttle it to the plasma membrane where it may form functional heterotrimeric receptors at the plasma membrane (PubMed:22378790). P2RX6 can be translocated to the nucleus and functions as a nuclear regulator of post-transcriptional modifications in neurons (By similarity). {ECO:0000250|UniProtKB:O54803, ECO:0000269|PubMed:22378790}. This is the function of ENSG00000099957 (P2RX6, purinergic receptor P2X 6).