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The cAMP-dependent kinase pathway does not sensitize the cloned vanilloid receptor type 1 expressed in Xenopus oocytes or Aplysia neurons
- Source :
- Neuroscience Letters. 288:57-60
- Publication Year :
- 2000
- Publisher :
- Elsevier BV, 2000.
-
Abstract
- Capsaicin-activated channels present in sensory neurons are ligand-gated cation channels that largely account for mediating some types of pain. The cAMP-dependent protein kinase (PKA) signal pathway was suggested to mediate the prostaglandin-induced enhancement of capsaicin-evoked inward current (I(CAP)) in rat sensory neurons. It is not clear, however, whether PKA acts directly on the capsaicin-sensitive channel that is responsible for I(CAP). To address this issue, we overexpressed the cloned capsaicin receptor, VR1, in heterologous expression systems such as Xenopus oocytes or Aplysia R2 neuron and stimulated PKA pathways. As a result, activation of PKA by applying either 8-bromo-cAMP or forskolin with 3-isobutyl-1-methylxanthine or through activation of beta(2) adrenergic receptors failed to enhance I(CAP) in oocytes or R2 neurons expressing VR1. Our results raise two possibilities. (1) Direct phosphorylation of VR1 by PKA may not be responsible for the sensitization; instead, phosphorylation of regulatory proteins associated with VR1 would account for the sensitization of I(CAP) evoked by prostaglandin E(2) in dorsal root ganglion (DRG) neurons. (2) DRG neurons may have a different PKA signaling mechanism that is not replicable in Xenopus oocytes or Aplysia R2 neurons.
- Subjects :
- Patch-Clamp Techniques
Phosphodiesterase Inhibitors
Receptors, Drug
Xenopus
TRPV1
8-Bromo Cyclic Adenosine Monophosphate
Gene Expression
TRPV Cation Channels
Transfection
Membrane Potentials
chemistry.chemical_compound
Dorsal root ganglion
1-Methyl-3-isobutylxanthine
Aplysia
medicine
Animals
Patch clamp
Cloning, Molecular
Protein kinase A
Neurons
Forskolin
biology
General Neuroscience
Colforsin
biology.organism_classification
Cyclic AMP-Dependent Protein Kinases
Molecular biology
Cell biology
medicine.anatomical_structure
nervous system
chemistry
Oocytes
Receptors, Adrenergic, beta-2
Neuron
Capsaicin
Signal Transduction
Subjects
Details
- ISSN :
- 03043940
- Volume :
- 288
- Database :
- OpenAIRE
- Journal :
- Neuroscience Letters
- Accession number :
- edsair.doi.dedup.....fab185296f3dee6ba22860b83993864d