Identification of an oncoprotein- and UV-responsive protein kinase that binds and potentiates the c-Jun activation domain

Genes Dev. 1993 Nov;7(11):2135-48. doi: 10.1101/gad.7.11.2135.


The activity of c-Jun is regulated by phosphorylation. Various stimuli including transforming oncogenes and UV light, induce phosphorylation of serines 63 and 73 in the amino-terminal activation domain of c-Jun and thereby potentiate its trans-activation function. We identified a serine/threonine kinase whose activity is stimulated by the same signals that stimulate the amino-terminal phosphorylation of c-Jun. This novel c-Jun amino-terminal kinase (JNK), whose major form is 46 kD, binds to a specific region within the c-Jun trans-activation domain and phosphorylates serines 63 and 73. Phosphorylation results in dissociation of the c-Jun-JNK complex. Mutations that disrupt the kinase-binding site attenuate the response of c-Jun to Ha-Ras and UV. Therefore the binding of JNK to c-Jun is of regulatory importance and suggests a mechanism through which protein kinase cascades can specifically modulate the activity of distinct nuclear targets.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Line
  • Cell Line, Transformed
  • Genes, ras
  • Glutathione Transferase / biosynthesis
  • Glutathione Transferase / metabolism
  • HeLa Cells
  • Humans
  • JNK Mitogen-Activated Protein Kinases
  • Mice
  • Mitogen-Activated Protein Kinases*
  • Molecular Weight
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Serine-Threonine Kinases / metabolism*
  • Protein Serine-Threonine Kinases / radiation effects
  • Proto-Oncogene Proteins c-jun / biosynthesis
  • Proto-Oncogene Proteins c-jun / metabolism*
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / metabolism
  • Serine
  • Transfection
  • Ultraviolet Rays*


  • Proto-Oncogene Proteins c-jun
  • Recombinant Fusion Proteins
  • Serine
  • Glutathione Transferase
  • Protein Serine-Threonine Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases