Bradykinin Controls Pool Size of Sensory Neurons Expressing Functional  -Opioid Receptors

Molecular Pharmacology ofδ-Opioid Receptors

“…Other evidence that DOPrs are targeted to the plasma membrane via the regulated secretory pathway arises from studies demonstrating that a painful (noxious) stimulus causes membrane trafficking of the receptor. For example, Patwardhan et al (2005) demonstrated that DOPr membrane trafficking was produced by the inflammatory mediator bradykinin (BK) (Patwardhan et al, 2005), a finding replicated by others (Pettinger et al, 2013). The d-Opioid Receptor Pharmacology regulated trafficking of DOPr via BK was demonstrated by total internal reflection fluorescence microscopy of trigeminal and dorsal root sensory neurons transfected with DOPr fused with eGFP (Pettinger et al, 2013).…”

“…Nevertheless, stimulated DOPr membrane trafficking has been identified in transgenic knock-in DOPr-eGFP mice (BertranGonzalez et al, 2013) and these mice can be used reliably to study ligand-induced intracellular redistribution of receptors (Pradhan et al, 2009(Pradhan et al, , 2010(Pradhan et al, , 2015Faget et al, 2012). In addition, despite the altered trafficking and/or visualization of receptors with the eGFP tag, this fusion protein was not found to significantly alter the physiologic effects produced by DOPr activation via exogenous agonists (Pradhan et al, 2010;Bertran-Gonzalez et al, 2013;Pettinger et al, 2013;Bardoni et al, 2014). Table 2 summarizes the evidence and the strengths and weaknesses of the approaches that have been used to identify subcellular localization of DOPr.…”

“…However, again, we should caution reliance on eGFP-tagged DOPr knock-in mice for visualization of DOPr distribution, because intermolecular disulfide bonded eGFP that is nonfluorescent was shown to confound quantification of total levels of GFP in secretory pathways (including with use of GFP antibodies) (Jokitalo et al, 2001;Aronson et al, 2011). Similarly, studies also report conflicting results over whether DOPr expression exists in calcitonin gene-related peptide (CGRP) sensory neurons Pettinger et al, 2013). However, electrophysiological data with patch-clamp experiments and CGRP release assays strongly suggest significant coexpression of DOPr with this neuropeptide (Pettinger et al, 2013).…”

“…Similarly, studies also report conflicting results over whether DOPr expression exists in calcitonin gene-related peptide (CGRP) sensory neurons Pettinger et al, 2013). However, electrophysiological data with patch-clamp experiments and CGRP release assays strongly suggest significant coexpression of DOPr with this neuropeptide (Pettinger et al, 2013). Other evidence that DOPrs are targeted to the plasma membrane via the regulated secretory pathway arises from studies demonstrating that a painful (noxious) stimulus causes membrane trafficking of the receptor.…”

Activation of m1 muscarinic acetylcholine receptor induces surface transport of KCNQ channel via CRMP-2 mediated pathway

“…For decades, SCG neurons have been a standard experimental system for M-current research (Delmas and Brown, 2005;Hoshi et al, 2005). However, we found that performing the TIRF assay on cultured SCG neurons was very difficult because neurons often grew on top of other cell types and made poor contact with the cover glass, as described previously by another group (Pettinger et al, 2013). Therefore, we constructed a pH-sensitive GFP construct, superecliptic pHluorin, which was inserted within the S1-S2 loop of the KCNQ2 subunit, a region that has also been used for insertion of the hemagglutinin (HA) epitope for surface detection (Chung et al, 2006;Schwake et al, 2003).…”