From Cell Structure to Transcription: Hippo Forges a New Path

Cell. 2006 Jan 27;124(2):267-73. doi: 10.1016/j.cell.2006.01.005.


The control of cell number during animal development is a longstanding puzzle. Recent studies in the fruit fly Drosophila melanogaster have defined a new signaling pathway that restricts cell proliferation in differentiating epithelia. The cytoskeletal proteins Merlin and Expanded, which play a role in cell adhesion and structure, control the activation of the Hippo/Salvador kinase complex, which in turn activates the Warts/Mats kinase complex. Warts/Mats kinase phosphorylates and inhibits Yorkie, a transcriptional coactivator that positively regulates cell growth, survival, and proliferation. This conserved signaling pathway contains several tumor-suppressor genes and regulates the contact inhibition of proliferation in cultured cells.

Publication types

  • Review

MeSH terms

  • Animals
  • Cell Cycle Proteins / physiology
  • Cell Differentiation / physiology
  • Cell Proliferation*
  • Drosophila
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism
  • Drosophila Proteins / physiology
  • Epithelial Cells / chemistry
  • Epithelial Cells / cytology*
  • Gene Expression Regulation / physiology
  • Intracellular Signaling Peptides and Proteins
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / physiology*
  • Signal Transduction / physiology*


  • Cell Cycle Proteins
  • Drosophila Proteins
  • Intracellular Signaling Peptides and Proteins
  • sav protein, Drosophila
  • Protein-Serine-Threonine Kinases
  • hpo protein, Drosophila