Angiotensin II induces diverse signal transduction pathways via both Gq and Gi proteins in liver epithelial cells
✍ Scribed by Oxana M. Tsygankova; Ming Peng; Judith A. Maloney; Nancy Hopkins; John R. Williamson
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 113 KB
- Volume
- 69
- Category
- Article
- ISSN
- 0730-2312
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✦ Synopsis
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.