The Rho Guanine Nucleotide Exchange Factor DRhoGEF2 Is a Genetic Modifier of the PI3K Pathway in Drosophila

PLoS One. 2016 Mar 25;11(3):e0152259. doi: 10.1371/journal.pone.0152259. eCollection 2016.

Abstract

The insulin/IGF-1 signaling pathway mediates various physiological processes associated with human health. Components of this pathway are highly conserved throughout eukaryotic evolution. In Drosophila, the PTEN ortholog and its mammalian counterpart downregulate insulin/IGF signaling by antagonizing the PI3-kinase function. From a dominant loss-of-function genetic screen, we discovered that mutations of a Dbl-family member, the guanine nucleotide exchange factor DRhoGEF2 (DRhoGEF22(l)04291), suppressed the PTEN-overexpression eye phenotype. dAkt/dPKB phosphorylation, a measure of PI3K signaling pathway activation, increased in the eye discs from the heterozygous DRhoGEF2 wandering third instar larvae. Overexpression of DRhoGEF2, and it's functional mammalian ortholog PDZ-RhoGEF (ArhGEF11), at various stages of eye development, resulted in both dPKB/Akt-dependent and -independent phenotypes, reflecting the complexity in the crosstalk between PI3K and Rho signaling in Drosophila.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins
  • Drosophila / genetics*
  • Drosophila / growth & development
  • Drosophila Proteins / biosynthesis
  • Drosophila Proteins / genetics*
  • Eye / growth & development*
  • Eye / metabolism
  • Gene Expression Regulation, Developmental
  • Humans
  • Insulin / genetics
  • Insulin-Like Growth Factor I / genetics
  • Mutation
  • Phosphatidylinositol 3-Kinases / genetics*
  • Proto-Oncogene Proteins c-akt / genetics
  • Signal Transduction
  • rho GTP-Binding Proteins / biosynthesis
  • rho GTP-Binding Proteins / genetics*

Substances

  • Cell Cycle Proteins
  • Drosophila Proteins
  • Insulin
  • sav protein, Drosophila
  • Insulin-Like Growth Factor I
  • Proto-Oncogene Proteins c-akt
  • rho GTP-Binding Proteins

Grants and funding

This work was funded by Canadian Cancer Society Research Institute Innovation Grant number 701683 to VS.