Signaling efficiency of Gαq through its effectors p63RhoGEF and GEFT depends on their subcellular location

Sci Rep. 2013;3:2284. doi: 10.1038/srep02284.

Abstract

The p63RhoGEF and GEFT proteins are encoded by the same gene and both members of the Dbl family of guanine nucleotide exchange factors. These proteins can be activated by the heterotrimeric G-protein subunit Gαq. We show that p63RhoGEF is located at the plasma membrane, whereas GEFT is confined to the cytoplasm. Live-cell imaging studies yielded quantitative information on diffusion coefficients, association rates and encounter times of GEFT and p63RhoGEF. Calcium signaling was examined as a measure of the signal transmission, revealing more efficient signaling through the membrane-associated p63RhoGEF. A rapamycin dependent recruitment system was used to dynamically alter the subcellular location and concentration of GEFT, showing efficient signaling through GEFT only upon membrane recruitment. Together, our results show efficient signal transmission through membrane located effectors, and highlight a role for increased concentration rather than increased encounter times due to membrane localization in the Gαq mediated pathways to p63RhoGEF and PLCβ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Calcium Signaling
  • Cell Membrane / metabolism
  • Cysteine / chemistry
  • Cytoplasm / metabolism
  • GTP-Binding Protein alpha Subunits, Gq-G11 / genetics
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism*
  • Gene Expression
  • Gene Ontology
  • Genetic Vectors / genetics
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • HeLa Cells
  • Humans
  • Intracellular Space / metabolism
  • Kinetics
  • Microscopy, Confocal
  • Models, Biological
  • Molecular Sequence Data
  • Phospholipase C beta / metabolism
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Transport
  • Rho Guanine Nucleotide Exchange Factors / genetics
  • Rho Guanine Nucleotide Exchange Factors / metabolism*
  • Signal Transduction*

Substances

  • GEFT protein, human
  • Guanine Nucleotide Exchange Factors
  • Rho Guanine Nucleotide Exchange Factors
  • p63RhoGEF protein, human
  • Phospholipase C beta
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Cysteine