C-terminal Dimerization Activates the Nociceptive Transduction Channel Transient Receptor Potential Vanilloid 1

• Published in: The Journal of biological chemistry Vol. 286; no. 47; pp. 40601 - 40607
• Main Authors: Wang, Shu, Chuang, Huai-hu
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25-11-2011; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Amino Acid Substitution; Animals; Arsenicals - pharmacology; Capsaicin Receptor; Cell Membrane - metabolism; Chickens; Cysteine; HEK293 Cells; Humans; Hydrogen Peroxide - pharmacology; Ion Channels; Molecular Sequence Data; Mutation; Nociception - drug effects; Oxidation-Reduction; Oxidative Stress; Peptide Fragments - chemistry; Peptide Fragments - metabolism; Protein Chemical Modification; Protein Multimerization; Protein Structure, Quaternary; Protein Subunits - chemistry; Protein Subunits - genetics; Protein Subunits - metabolism; Rats; Receptor Structure-Function; Signal Transduction; Signal Transduction - drug effects; Sulfhydryl Compounds - chemistry; TRPV Cation Channels - chemistry; TRPV Cation Channels - genetics; TRPV Cation Channels - metabolism; Receptor Structure-Function; Ion Channels; Oxidative Stress; Signal Transduction; Protein Chemical Modification; Capsaicin Receptor
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M111.256669

Covalent modification of the specific cysteine residue(s) by oxidative stress robustly potentiates transient receptor potential vanilloid 1 (TRPV1) and sensitizes nociception. Here we provide biochemical evidence of dimerization of TRPV1 subunits upon exposure to phenylarsine oxide and hydrogen peroxide (H2O2), two chemical surrogates of oxidative stress. A disulfide bond formed between apposing cysteines ligates two C termini, serving as the structural basis of channel sensitization by oxidative covalent C-terminal modification. Systematic cysteine scanning of the C terminus of a cysteineless TRPV1 channel revealed a critical region within which any cysteine introduced phenylarsine oxide activation to mutant TRPV1. Oxidative sensitization persisted even when this region is substituted with a random peptide linker containing a single cysteine. So did insertion of this region to TRPV3, a homolog lacking the corresponding region and resistant to oxidative challenge. These results suggest that the non-conserved linker in the TRPV1 C terminus senses environmental oxidative stress and adjusts channel activity during cumulative oxidative damage by lowering the activation threshold of gating elements shared by TRPV channels.
Background: Oxidation sensitizes nociception by covalent cysteine modification of pain transduction transient receptor potential vanilloid 1 (TRPV1) channels.
Results: Cysteines within a unique C-terminal region are ligated to form intersubunit disulfide bonds to sensitize TRPV1.
Conclusion: Dimerization of adjacent C termini activates TRPV1.
Significance: This is potentially the first example of channel activation by physical approximation of two intrinsically unstructured peptide linkers.