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Updated: May 3, 2026

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
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Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development

Published on: June 15, 2017

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Yan functions as a general inhibitor of differentiation and is negatively regulated by activation of the Ras1/MAPK

I Rebay1, G M Rubin

  • 1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.

Cell
|June 16, 1995
PubMed

Insights

Mutagenizing Drosophila yan

Area of Science:

  • Developmental biology
  • Cell signaling
  • Molecular genetics

Background:

  • The proneural signal in Drosophila development is mediated by the sevenless/Ras1/MAPK pathway.
  • The yan protein is thought to antagonize this proneural signal.

Purpose of the Study:

  • To investigate the role of MAPK phosphorylation sites in yan function.
  • To understand how MAPK signaling regulates yan activity during development.

Main Methods:

  • Mutagenesis of eight MAPK phosphorylation consensus sites in the yan gene.
  • Overexpression of wild-type and mutant yan proteins in transgenic Drosophila.
  • Analysis of yan protein in transfected S2 cultured cells.

Main Results:

  • MAPK phosphorylation of yan affects its stability and subcellular localization.
  • Phosphorylation leads to rapid down-regulation of yan activity.
  • MAPK-mediated yan down-regulation is crucial for neuronal and nonneuronal tissue differentiation.

Conclusions:

  • MAPK signaling regulates yan activity through phosphorylation, impacting protein stability and localization.
  • Down-regulation of yan by MAPK is essential for proper tissue differentiation in Drosophila.
  • Yan acts as a key component in a general developmental timing mechanism controlling cellular responsiveness to inductive signals.

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