FGFR/Heartless and Smog interact synergistically to negatively regulate Fog mediated G-protein coupled receptor signaling in the Drosophila nervous system

G3 (Bethesda). 2021 Mar 16;11(3):jkaa029. doi: 10.1093/g3journal/jkaa029.


Folded gastrulation (Fog) is a secreted ligand that signals through the G-protein-coupled receptors Mist and Smog and the G-protein Concertina to activate downstream effectors to elicit cell-shape change during gastrulation. In the embryonic central nervous system (CNS), Fog has roles in axon guidance and glial morphogenesis. However, the elements of the pathway as well as mechanisms required for transducing the signal in this context have not been determined. We find that while Concertina is essential for Fog signaling, Mist is dispensable and Smog, surprisingly, functions as a negative regulator of the pathway in the CNS. Interestingly Heartless, a fibroblast growth factor receptor, also functions as a negative regulator. Furthermore, both Heartless and Smog interact in a synergistic manner to regulate Fog signaling. Our results thus identify Heartless and Smog as part of a common regulatory pathway that functions to restrict Fog signaling in the embryonic CNS and highlights the context-specific role for Fog receptors during development.

Keywords: Drosophila; Fog; Glia; Smog; heartless.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila Proteins* / metabolism
  • Drosophila* / metabolism
  • Gastrulation
  • Neuroglia / metabolism
  • Protein-Tyrosine Kinases
  • Receptors, Fibroblast Growth Factor* / metabolism
  • Receptors, G-Protein-Coupled*


  • Drosophila Proteins
  • Receptors, Fibroblast Growth Factor
  • Receptors, G-Protein-Coupled
  • Protein-Tyrosine Kinases
  • htl protein, Drosophila

Associated data

  • figshare/10.25387/g3.12813299