Protein kinase N (PKN) and PKN-related protein rhophilin as targets of small GTPase Rho

Science. 1996 Feb 2;271(5249):645-8. doi: 10.1126/science.271.5249.645.


The Rho guanosine 5'-triphosphatase (GTPase) cycles between the active guanosine triphosphate (GTP)-bound form and the inactive guanosine diphosphate-bound form and regulates cell adhesion and cytokinesis, but how it exerts these actions is unknown. The yeast two-hybrid system was used to clone a complementary DNA for a protein (designated Rhophilin) that specifically bound to GTP-Rho. The Rho-binding domain of this protein has 40 percent identity with a putative regulatory domain of a protein kinase, PKN. PKN itself bound to GTP-Rho and was activated by this binding both in vitro and in vivo. This study indicates that a serine-threonine protein kinase is a Rho effector and presents an amino acid sequence motif for binding to GTP-Rho that may be shared by a family of Rho target proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Cloning, Molecular
  • Enzyme Activation
  • GTP Phosphohydrolases / metabolism*
  • GTP-Binding Proteins / chemistry
  • GTP-Binding Proteins / metabolism*
  • Guanosine Triphosphate / metabolism
  • Humans
  • Membrane Proteins / metabolism*
  • Mice
  • Molecular Sequence Data
  • Phosphorylation
  • Protein Kinase C / chemistry
  • Protein Kinase C / metabolism*
  • Protein-Serine-Threonine Kinases*
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Signal Transduction
  • ras Proteins
  • rho GTP-Binding Proteins*
  • rhoA GTP-Binding Protein
  • rhoB GTP-Binding Protein
  • rhoC GTP-Binding Protein


  • Adaptor Proteins, Signal Transducing
  • Membrane Proteins
  • Recombinant Fusion Proteins
  • rhophilin
  • Guanosine Triphosphate
  • protein kinase N
  • Protein-Serine-Threonine Kinases
  • Protein Kinase C
  • GTP Phosphohydrolases
  • GTP-Binding Proteins
  • RHOC protein, human
  • Rhoc protein, mouse
  • ras Proteins
  • rho GTP-Binding Proteins
  • rhoA GTP-Binding Protein
  • rhoB GTP-Binding Protein
  • rhoC GTP-Binding Protein

Associated data

  • GENBANK/U43194