<p id="P3">Transcripts of noxious stimulus-detecting TrpA1 channels are alternatively
Despite the importance of nociception for survival, the
<i>in vivo</i> significance of expressing different
<i>TrpA1</i> isoforms is largely unknown. Here we develop a novel genetic approach
<i>Drosophila</i> knock-in strains expressing single TrpA1 isoforms.
<i>Drosophila</i> TrpA1 mediates heat and UVC-triggered nociception. We show TrpA1-C
and TrpA1-D, two
alternative isoforms, are co-expressed in nociceptors. When examined in heterologous
cells, both TrpA1-C and TrpA1-D are activated by heat and UVC. By contrast, analysis
of knock-in flies reveals the striking functional specificity; TrpA1-C mediates UVC-nociception,
whereas TrpA1-D mediates heat-nociception. Therefore,
<i>in vivo</i> functions of TrpA1-C and TrpA1-D are different from each other, and
<i>in vitro</i> properties. Our results indicate that a given sensory stimulus preferentially
a single TrpA1 isoform
<i>in vivo</i>, and that polymodal nociception requires co-expression of TrpA1 isoforms,
novel insights of how alternative splicing regulates nociception.
<i>et al</i>. demonstrate that heat and UVC light preferentially activate distinct
<i>Drosophila</i> TrpA1 isoforms
<i>in vivo</i>, and polymodal nociception requires co-expression of TrpA1-C and TrpA1-D.