Opioid inhibition of N-type Ca2+ channels and spinal analgesia couple to alternative splicing.
Alternative pre-mRNA splicing occurs extensively in the nervous systems of complex organisms, including humans, considerably expanding the potential size of the proteome. Cell-specific alternative pre-mRNA splicing is thought to optimize protein function for specialized cellular tasks, but direct evidence for this is limited. Transmission of noxious thermal stimuli relies on the activity of N-type Ca(V)2.2 calcium channels in nociceptors. Using an exon-replacement strategy in mice, we show that mutually exclusive splicing patterns in the Ca(V)2.2 gene modulate N-type channel function in nociceptors, leading to a change in morphine analgesia. Exon 37a (e37a) enhances μ-opioid receptor-mediated inhibition of N-type calcium channels by promoting activity-independent inhibition. In the absence of e37a, spinal morphine analgesia is weakened in vivo but the basal response to noxious thermal stimuli is not altered. Our data suggest that highly specialized, discrete cellular responsiveness in vivo can be attributed to alternative splicing events regulated at the level of individual neurons.
Andrade
Arturo
A
Department of Neuroscience, Brown University, Providence, Rhode Island, USA.
Denome
Sylvia
S
Jiang
Yu-Qiu
YQ
Marangoudakis
Spiro
S
Lipscombe
Diane
D
D017398:Alternative Splicing / Q000187:drug effects*; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020864:Calcium Channels, N-Type / Q000235:genetics*; D004195:Disease Models, Animal; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D004622:Embryo, Mammalian; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D005091:Exons / Q000235:genetics; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006930:Hyperalgesia / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D037102:Lectins / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009020:Morphine / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D020866:omega-Conotoxin GVIA / Q000494:pharmacology
D000701:Analgesics, Opioid; C500963:Cacna1b protein, mouse; D002121:Calcium Channel Blockers; D020864:Calcium Channels, N-Type; D037102:Lectins; D012333:RNA, Messenger; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009020:Morphine; D020866:omega-Conotoxin GVIA; D015740:Calcitonin Gene-Related Peptide