[摘要] The authors describe a new version of the P2X7 receptor, P2X7k, which starts at an alternative transcription initiation site in what was thought to be a large intron between the first and second exons. This provides a functional receptor with an alternative first transmembrane domain. There are three key findings of this work: (1) the P2X7k receptor has distinct signaling properties and notably undergoes pore dilation very rapidly; (2) it strengthens the case that pore dilation is a property of the P2X7 protein rather than additional proteins; and (3) in transgenic mice where gene silencing of the P2X7 receptor has been attempted by removal of the first exon, P2X7k is still expressed and is functional.
