puckered encodes a phosphatase that mediates a feedback loop regulating JNK activity during dorsal closure in Drosophila

  1. Enrique Martín-Blanco,
  2. Alexandra Gampel,
  3. Jenny Ring,
  4. Kanwar Virdee,
  5. Nikolai Kirov,
  6. Aviva M. Tolkovsky, and
  7. Alfonso Martinez-Arias
  1. Department of Zoology and Department of Biochemistry, University of Cambridge, Cambridge CB2 3EJ, UK; Department of Biology, New York University, New York, New York 10003 USA

Abstract

The activation of MAPKs is controlled by the balance between MAPK kinase and MAPK phosphatase activities. The latter is mediated by a subset of phosphatases with dual specificity (VH-1 family). Here, we describe a new member of this family encoded by the puckeredgene of Drosophila. Mutations in this gene lead to cytoskeletal defects that result in a failure in dorsal closure related to those associated with mutations in basket, the Drosophila JNK homolog. We show that puckered mutations result in the hyperactivation of DJNK, and that overexpression of puc mimicsbasket mutant phenotypes. We also show that puckeredexpression is itself a consequence of the activity of the JNK pathway and that during dorsal closure, JNK signaling has a dual role: to activate an effector, encoded by decapentaplegic, and an element of negative feedback regulation encoded by puckered.

Keywords

Footnotes

  • Present address: Department of Human Anatomy, University of Oxford, Oxford, UK.

  • Corresponding author.

  • E-MAIL ama11{at}cus.cam.ac.uk; FAX 44-1223-336676.

    • Received September 26, 1997.
    • Accepted November 18, 1997.
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