Oriented Cell Division in the C. elegans Embryo Is Coordinated by G-Protein Signaling Dependent on the Adhesion GPCR LAT-1

PLoS Genet. 2015 Oct 27;11(10):e1005624. doi: 10.1371/journal.pgen.1005624. eCollection 2015 Oct.

Abstract

Orientation of spindles and cell division planes during development of many species ensures that correct cell-cell contacts are established, which is vital for proper tissue formation. This is a tightly regulated process involving a complex interplay of various signals. The molecular mechanisms underlying several of these pathways are still incompletely understood. Here, we identify the signaling cascade of the C. elegans latrophilin homolog LAT-1, an essential player in the coordination of anterior-posterior spindle orientation during the fourth round of embryonic cell division. We show that the receptor mediates a G protein-signaling pathway revealing that G-protein signaling in oriented cell division is not solely GPCR-independent. Genetic analyses showed that through the interaction with a Gs protein LAT-1 elevates intracellular cyclic AMP (cAMP) levels in the C. elegans embryo. Stimulation of this G-protein cascade in lat-1 null mutant nematodes is sufficient to orient spindles and cell division planes in the embryo in the correct direction. Finally, we demonstrate that LAT-1 is activated by an intramolecular agonist to trigger this cascade. Our data support a model in which a novel, GPCR-dependent G protein-signaling cascade mediated by LAT-1 controls alignment of cell division planes in an anterior-posterior direction via a metabotropic Gs-protein/adenylyl cyclase pathway by regulating intracellular cAMP levels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / genetics
  • Adenylyl Cyclases / metabolism
  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / growth & development
  • Cell Adhesion / genetics
  • Cell Division / genetics*
  • Cyclic AMP / genetics
  • Embryo, Nonmammalian
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism*
  • Large Neutral Amino Acid-Transporter 1 / genetics*
  • Large Neutral Amino Acid-Transporter 1 / metabolism
  • Signal Transduction

Substances

  • Large Neutral Amino Acid-Transporter 1
  • Cyclic AMP
  • GTP-Binding Proteins
  • Adenylyl Cyclases

Grants and funding

This work was supported by grants from the Deutsche Forschungsgemeinschaft (FOR2149 (SP, TSc), Pr1534/1-1 (SP), Sfb610 (TSc)), the European Social Funds (TSc), the Medical Faculty, Leipzig University (Formel 1 junior research grant (SP)) and by a PhD studentship from the Studienstiftung des Deutschen Volkes (TSa). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.