The genomic organization of the gene encoding the vanilloid receptor: evidence for multiple splice variants.

Abstract Vanilloid receptor subtype-1 (VR1) is a nonselective cation channel that is expressed in sensory neurons and is activated by multiple noxious stimuli. Rat Vr1, stretch-inactivated channel (SIC), and vanilloid receptor 5′ splice variant (VR.5′sv) have been hypothesized to be derived from a common VR gene. Characterization of the genomic structure encoding the 5′ portion of rat Vr1 confirmed that VR.5′sv is derived from the VR gene; however, SIC seemed to be derived from two related but independent genes. We also deduced the genomic organization of the human gene VR1 . Comparative studies of rat and human VR genes showed substantial conservation in genomic organization. The splice site flanking exon–intron 7 in rat and human VR1 diverged from the expected consensus sequence; this may help to explain the skipping of exon 7 within VR.5′sv and other VR splice variants.