Regulation of Golgi structure and secretion by receptor-induced G protein βγ complex translocation

Proc Natl Acad Sci U S A. 2010 Jun 22;107(25):11417-22. doi: 10.1073/pnas.1003042107. Epub 2010 Jun 7.

Abstract

We show that receptor induced G protein betagamma subunit translocation from the plasma membrane to the Golgi allows a receptor to initiate fragmentation and regulate secretion. A lung epithelial cell line, A549, was shown to contain an endogenous translocating G protein gamma subunit and exhibit receptor-induced Golgi fragmentation. Receptor-induced Golgi fragmentation was inhibited by a shRNA specific to the endogenous translocating gamma subunit. A kinase defective protein kinase D and a phospholipase C beta inhibitor blocked receptor-induced Golgi fragmentation, suggesting a role for this process in secretion. Consistent with betagamma translocation dependence, fragmentation induced by receptor activation was inhibited by a dominant negative nontranslocating gamma3. Insulin secretion was shown to be induced by muscarinic receptor activation in a pancreatic beta cell line, NIT-1. Induction of insulin secretion was also inhibited by the dominant negative gamma3 subunit consistent with the Golgi fragmentation induced by betagamma complex translocation playing a role in secretion.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • GTP-Binding Protein beta Subunits / metabolism*
  • GTP-Binding Protein gamma Subunits / metabolism*
  • Genes, Dominant
  • Golgi Apparatus / metabolism*
  • Humans
  • Insulin / metabolism
  • Mice
  • Microscopy, Fluorescence / methods
  • Microtubules / metabolism
  • Phospholipase C beta / metabolism
  • Protein Kinase C / metabolism
  • Protein Transport
  • Receptors, Muscarinic / metabolism
  • Signal Transduction

Substances

  • G-protein Beta gamma
  • GTP-Binding Protein beta Subunits
  • GTP-Binding Protein gamma Subunits
  • Insulin
  • Receptors, Muscarinic
  • protein kinase D
  • Protein Kinase C
  • Phospholipase C beta