Alexandros H Kanellopoulos 1 , Jennifer Koenig 1 , Honglei Huang 2 , Martina Pyrski 3 , Queensta Millet 1 , Stéphane Lolignier 1 , 4 , Toru Morohashi 1 , Samuel J Gossage 1 , Maude Jay 1 , John E Linley 1 , 5 , Georgios Baskozos 6 , Benedikt M Kessler 2 , James J Cox 1 , Annette C Dolphin 7 , Frank Zufall 3 , John N Wood , 1 , Jing Zhao , 1
15 January 2018
The voltage‐gated sodium channel Na V1.7 plays a critical role in pain pathways. We generated an epitope‐tagged Na V1.7 mouse that showed normal pain behaviours to identify channel‐interacting proteins. Analysis of Na V1.7 complexes affinity‐purified under native conditions by mass spectrometry revealed 267 proteins associated with Nav1.7 in vivo. The sodium channel β3 (Scn3b), rather than the β1 subunit, complexes with Nav1.7, and we demonstrate an interaction between collapsing‐response mediator protein (Crmp2) and Nav1.7, through which the analgesic drug lacosamide regulates Nav1.7 current density. Novel Na V1.7 protein interactors including membrane‐trafficking protein synaptotagmin‐2 (Syt2), L‐type amino acid transporter 1 (Lat1) and transmembrane P24‐trafficking protein 10 (Tmed10) together with Scn3b and Crmp2 were validated by co‐immunoprecipitation (Co‐IP) from sensory neuron extract. Nav1.7, known to regulate opioid receptor efficacy, interacts with the G protein‐regulated inducer of neurite outgrowth (Gprin1), an opioid receptor‐binding protein, demonstrating a physical and functional link between Nav1.7 and opioid signalling. Further information on physiological interactions provided with this normal epitope‐tagged mouse should provide useful insights into the many functions now associated with the Na V1.7 channel.