The deubiquitinating enzyme USP5 modulates neuropathic and inflammatory pain by enhancing Cav3.2 channel activity
Résumé
T-type calcium channels are essential contributors to the transmission of nociceptive signals in the primary afferent pain pathway. Here, we show that T-type calcium channels are ubiquitinated by WWP1, a plasma-membrane-associated ubiquitin ligase that binds to the intracellular domain III-IV linker region of the Cav3.2 T-type channel and modifies specific lysine residues in this region. A proteomic screen identified the deubiquitinating enzyme USP5 as a Cav3.2 III-IV linker interacting partner. Knockdown of USP5 via shRNA increases Cav3.2 ubiquitination, decreases Cav3.2 protein levels, and reduces Cav3.2 whole-cell currents. In vivo knockdown of USP5 or uncoupling USP5 from native Cav3.2 channels via intrathecal delivery of Tat peptides mediates analgesia in both inflammatory and neuropathic mouse models of mechanical hypersensitivity. Altogether, our experiments reveal a cell signaling pathway that regulates T-type channel activity and their role in nociceptive signaling.
Mots clés
Mice
Animals
Male
Humans
Transgenic
Membrane Potentials/drug effects/genetics
Peptides/therapeutic use
Sensory Receptor Cells/drug effects/physiology
Spinal Cord/cytology
Ubiquitination/genetics/physiology
Neuralgia/drug therapy/*enzymology
Pain Threshold/drug effects/physiology
Animal
In Vitro Techniques
Cells
Cultured
Calcium Channels
T-Type/genetics/*metabolism
Transfection
Endopeptidases/genetics/*metabolism
Freund's Adjuvant/toxicity
Hyperalgesia/diagnosis/physiopathology
Inflammation/chemically induced/*physiopathology
Nerve Tissue Proteins/metabolism
Disease Models
Inbred C57BL