Faculty Collaboration Database

Protein-tyrosine kinase Pyk2 mediates endothelin-induced p38 MAPK activation in glomerular mesangial cells. J Biol Chem 2001 Jun 15;276(24):21521-8

Date

03/30/2001

Pubmed ID

11278444

DOI

10.1074/jbc.M008869200

Scopus ID

2-s2.0-0035877806 (requires institutional sign-in at Scopus site)   65 Citations

Abstract

Endothelin-1 (ET-1), a member of a family of 21 amino acid peptides possessing vasoconstrictor properties, is known to stimulate mesangial cell proliferation. In this study, ET-1 (100 nm) induced a rapid activation of p21(ras) in human glomerular mesangial cells (HMC). Inhibition of Src family tyrosine kinase activation with [4-Amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine] or chelation of intracellular free calcium with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester significantly decreased ET-1dependent p21(ras) activation and suggested the involvement of the cytoplasmic proline-rich tyrosine kinase Pyk2. We have observed that Pyk2 was expressed in HMC and was tyrosine-phosphorylated within 5 min of ET-1 treatment. ET-1-induced activation of Pyk2 was further confirmed using phospho-specific anti-Pyk2 antibodies. Surprisingly, Src kinase activity was required upstream of ET-1-induced autophosphorylation of Pyk2. To determine whether Pyk2 autophosphorylation mediated ET-1-dependent p21(ras) activation, adenovirus-mediated transfer was employed to express a dominant-negative form of Pyk2 (CRNK). CRNK expression inhibited ET-1-induced endogenous Pyk2 autophosphorylation, but did not abolish ET-1-mediated increases in GTP-bound p21(ras) levels. ET-1-induced activation of the p38 MAPK (but not ERK) pathway was inhibited in HMC and in rat glomerular mesangial cells expressing the dominant-negative form of Pyk2. These findings suggest that the engagement of Pyk2 is important for ET-1-mediated p38 MAPK activation and hence the biological effect of this peptide in mesangial cells.

Author List

Sorokin A, Kozlowski P, Graves L, Philip A

Author

Andrey Sorokin PhD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adenoviridae
Cell Line, Transformed
Chelating Agents
Egtazic Acid
Endothelin-1
Enzyme Activation
Enzyme Inhibitors
Focal Adhesion Kinase 2
Genes, Reporter
Genetic Vectors
Glomerular Mesangium
Humans
Kinetics
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase 3
Mitogen-Activated Protein Kinases
Models, Biological
Phosphorylation
Protein-Tyrosine Kinases
Proto-Oncogene Proteins p21(ras)
Pyrazoles
Pyrimidines
Recombinant Proteins
Simian virus 40
Transfection
p38 Mitogen-Activated Protein Kinases
src-Family Kinases