Ubiquitin-dependent down-regulation of the neurokinin-1 receptor

Cottrell, G. S. ORCID: https://orcid.org/0000-0001-9098-7627, Padilla, B., Pikios, S., Roosterman, D., Steinhoff, M., Gehringer, D., Grady, E. F. and Bunnett, N. W. (2006) Ubiquitin-dependent down-regulation of the neurokinin-1 receptor. The Journal of Biological Chemistry, 281 (38). pp. 27773-27783. ISSN 1083-351X doi: 10.1074/jbc.M603369200

Abstract/Summary

Transient stimulation with substance P (SP) induces endocytosis and recycling of the neurokinin-1 receptor (NK(1)R). The effects of sustained stimulation by high concentrations of SP on NK(1)R trafficking and Ca(2+) signaling, as may occur during chronic inflammation and pain, are unknown. Chronic exposure to SP (100 nm, 3 h) completely desensitized Ca(2+) signaling by wild-type NK(1)R (NK(1)Rwt). Resensitization occurred after 16 h, and cycloheximide prevented resensitization, implicating new receptor synthesis. Lysine ubiquitination of G-protein-coupled receptors is a signal for their trafficking and degradation. Lysine-deficient mutant receptors (NK(1)RDelta5K/R, C-terminal tail lysines; and NK(1)RDelta10K/R, all intracellular lysines) were expressed at the plasma membrane and were functional because they responded to SP by endocytosis and by mobilization of Ca(2+) ions. SP desensitized NK(1)Rwt, NK(1)RDelta5K/R, and NK(1)RDelta10K/R. However, NK(1)RDelta5K/R and NK(1)RDelta10K/R resensitized 4-8-fold faster than NK(1)Rwt by cycloheximide-independent mechanisms. NK(1)RDelta325 (a naturally occurring truncated variant) showed incomplete desensitization, followed by a marked sensitization of signaling. Upon labeling receptors in living cells using antibodies to extracellular epitopes, we observed that SP induced endocytosis of NK(1)Rwt, NK(1)RDelta5K/R, and NK(1)RDelta10K/R. After 4 h in SP-free medium, NK(1)RDelta5K/R and NK(1)RDelta10K/R recycled to the plasma membrane, whereas NK(1)Rwt remained internalized. SP induced ubiquitination of NK(1)Rwt and NK(1)RDelta5K/R as determined by immunoprecipitation under nondenaturing and denaturing conditions and detected with antibodies for mono- and polyubiquitin. NK(1)RDelta10K/R was not ubiquitinated. Whereas SP induced degradation of NK(1)Rwt, NK(1)RDelta5K/R and NK(1)RDelta10K/R showed approximately 50% diminished degradation. Thus, chronic stimulation with SP induces ubiquitination of the NK(1)R, which mediates its degradation and down-regulation.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/30275
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Division of Pharmacology No Reading authors. Back catalogue items
Uncontrolled Keywords	Animals Calcium/metabolism Cell Line Down-Regulation Endocytosis Protein Transport Rats Receptors, Neurokinin-1/chemistry/*metabolism Signal Transduction Structure-Activity Relationship Substance P/metabolism Ubiquitin/*metabolism
Publisher	American Society for Biochemistry and Molecular Biology
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