Angiotensin II induces diverse signal transduction pathways via both Gq and Gi proteins in liver epithelial cells

J Cell Biochem. 1998 Apr 1;69(1):63-71. doi: 10.1002/(sici)1097-4644(19980401)69:1<63::aid-jcb7>3.0.co;2-t.

Abstract

Angiotensin II stimulates a biphasic activation of Raf-1, MEK, and ERK in WB liver epithelial cells. The first peak of activity is rapid and transient and is followed by a sustained phase. Angiotensin II also causes a rapid activation of p21ras in these cells. Moreover, two Src family kinases (Fyn and Yes) were activated by angiotensin II in a time- and concentration-dependent manner. Microinjection of antibodies against Fyn and Yes blocked angiotensin II-induced DNA synthesis and c-Fos expression in WB cells, indicating an obligatory involvement of these tyrosine kinases in the activation of the ERK cascade by angiotensin II. Finally, substantial reduction of the angiotensin II-stimulated activation of Fyn, Raf-1, ERK, and expression of c-Fos by pertussis toxin pretreatment argues that G proteins of the Gi family as well as the Gq family are involved in angiotensin II-mediated mitogenic pathways in WB cells.

Publication types

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

MeSH terms

  • Angiotensin II / pharmacology*
  • Animals
  • Cell Line
  • Enzyme Activation / drug effects
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • GTP-Binding Proteins / metabolism*
  • Liver / cytology
  • Liver / drug effects*
  • Liver / metabolism*
  • MAP Kinase Kinase 1
  • Mitogen-Activated Protein Kinase Kinases*
  • Protein Serine-Threonine Kinases / metabolism
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-fos / metabolism
  • Proto-Oncogene Proteins c-fyn
  • Proto-Oncogene Proteins c-raf / metabolism
  • Proto-Oncogene Proteins c-yes
  • Rats
  • Signal Transduction / drug effects
  • src-Family Kinases*

Substances

  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-fos
  • Angiotensin II
  • Protein-Tyrosine Kinases
  • Fyn protein, rat
  • Proto-Oncogene Proteins c-fyn
  • Proto-Oncogene Proteins c-yes
  • src-Family Kinases
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-raf
  • MAP Kinase Kinase 1
  • Mitogen-Activated Protein Kinase Kinases
  • GTP-Binding Proteins