Strathprints Home | Open Access | Browse | Search | User area | Copyright | Help | Library Home | SUPrimo

Trypsin stimulates proteinase-activated receptor-2-dependent and -independent activation of mitogen-activated protein kinases

Belham, C M and Tate, R J and Scott, P H and Pemberton, A D and Miller, H R and Wadsworth, R M and Gould, G W and Plevin, R (1996) Trypsin stimulates proteinase-activated receptor-2-dependent and -independent activation of mitogen-activated protein kinases. Biochemical journal, 320 ( Pt . pp. 939-46. ISSN 0264-6021

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

We have examined protease-mediated activation of the mitogen-activated protein (MAP) kinase cascade in rat aortic smooth-muscle cells and bovine pulmonary arterial fibroblasts. Exposure of smooth-muscle cells to trypsin evoked rapid and transient activation of c-Raf-1, MAP kinase kinase 1 and 2 and MAP kinase that was sensitive to inhibition by soybean trypsin inhibitor. The actions of trypsin were closely mimicked by the proteinase-activated receptor 2 (PAR-2)-activating peptide sequence SLIGRL but not LSIGRL. Peak MAP kinase activation in response to both trypsin and SLIGRL was also dependent on concentration, with EC50 values of 12.1 +/- 3.4 nM and 62.5 +/- 4.5 microM respectively. Under conditions where MAP kinase activation by SLIGRL was completely desensitized by prior exposure of smooth-muscle cells to the peptide, trypsin-stimulated MAP kinase activity was markedly attenuated (78.9 +/- 15.1% desensitization), whereas the response to thrombin was only marginally affected (16.6 +/- 12.1% desensitization). Trypsin and SLIGRL also weakly stimulated the activation of the MAP kinase homologue p38 in smooth-muscle cells without any detectable activation of c-Jun N-terminal kinase. Strong activation of the MAP kinase cascade and modest activation of p38 by trypsin were also observed in fibroblasts, although in this cell type these effects were not mimicked by SLIGRL nor by the thrombin receptor-activating peptide SFLLRNPNDKYEPF. Reverse transcriptase-PCR analysis confirmed the presence of PAR-2 mRNA in smooth-muscle cells but not fibroblasts. Our results suggest that in vascular smooth-muscle cells, trypsin stimulates the activation of the MAP kinase cascade relatively selectively, in a manner consistent with an interaction with the recently described PAR-2. Activation of MAP kinase by trypsin in vascular fibroblasts, however, seems to be independent of PAR-2 and occurs by an undefined mechanism possibly involving novel receptor species.

Item type: Article
ID code: 35165
Keywords: aorta, enzyme activation, fibroblasts, forskolin, lung, kinase, protein kinases, oligopeptides, protein-serine-threonine kinases, protein-tyrosine kinases, Proto-Oncogene Proteins c-sis, rna messenger, rats, receptors, trypsin, trypsin inhibitors, Therapeutics. Pharmacology, Biochemistry, Cell Biology, Molecular Biology
Subjects: Medicine > Therapeutics. Pharmacology
Department: Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences
Faculty of Engineering > Civil and Environmental Engineering
Related URLs:
    Depositing user: Pure Administrator
    Date Deposited: 02 Nov 2011 10:53
    Last modified: 05 Sep 2014 12:50
    URI: http://strathprints.strath.ac.uk/id/eprint/35165

    Actions (login required)

    View Item