Visualization of dynamic trafficking of a protein kinase C betaII/green fluorescent protein conjugate reveals differences in G protein-coupled receptor activation and desensitization

J Biol Chem. 1998 Apr 24;273(17):10755-62. doi: 10.1074/jbc.273.17.10755.

Abstract

Protein kinase C (PKC) links various extracellular signals to intracellular responses and is activated by diverse intracellular factors including diacylglycerol, Ca2+, and arachidonic acid. In this study, using a fully functional green fluorescent protein conjugated PKCbetaII (GFP-PKCbetaII), we demonstrate a novel approach to study the dynamic redistribution of PKC in live cells in response to G protein-coupled receptor activation. Agonist-induced PKC translocation was rapid, transient, and selectively mediated by the activation of Gqalpha- but not Gsalpha- or Gialpha-coupled receptors. Interestingly, although the stimuli were continuously present, only one brief peak of PKC membrane translocation was observed, consistent with rapid desensitization of the signaling pathway. Moreover, when GFP-PKCbetaII was used to examine cross-talk between two Gqalpha-coupled receptors, angiotensin II type 1A receptor (AT1AR) and endothelin A receptor (ETAR), activation of ETARs resulted in a subsequent loss of AT1AR responsiveness, whereas stimulation of AT1ARs did not cause desensitization of the ETAR signaling. The development of GFP-PKCbetaII has allowed not only the real time visualization of the dynamic PKC trafficking in live cells in response to physiological stimuli but has also provided a direct and sensitive means in the assessment of activation and desensitization of receptors implicated in the phospholipase C signaling pathway.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Biological Transport
  • Cell Line
  • GTP-Binding Proteins / metabolism*
  • Green Fluorescent Proteins
  • Humans
  • Isoenzymes / chemistry
  • Isoenzymes / metabolism*
  • Luminescent Proteins / chemistry
  • Luminescent Proteins / metabolism*
  • Protein Kinase C / chemistry
  • Protein Kinase C / metabolism*
  • Protein Kinase C beta
  • Receptors, Cell Surface / metabolism*
  • Signal Transduction

Substances

  • Isoenzymes
  • Luminescent Proteins
  • Receptors, Cell Surface
  • Green Fluorescent Proteins
  • Protein Kinase C
  • Protein Kinase C beta
  • GTP-Binding Proteins