Endothelin, vasopressin, and angiotensin II enhance tyrosine phosphorylation by protein kinase C-dependent and -independent pathways in glomerular mesangial cells.

摘要: Protein tyrosine phosphorylation has not been considered to be important for cellular activation by phospholipase C-linked vasoactive peptides. We found that endothelin, angiotensin II, and vasopressin (AVP), peptides signal via C activation, rapidly enhanced of proteins approximate molecular mass 225, 190, 135, 120, 70 kDa in rat renal mesangial cells. The phosphorylated were cytosolic or membrane-associated, none integral the membrane, suggesting peptide receptors are on tyrosine. Epidermal growth factor (EGF), which does activate these cells, induced its own 175-kDa receptor, addition five identical those response AVP, II. This suggests cells there is a common signaling pathway C-coupled agonists classically assumed receptor kinase pathways, such as EGF. phorbol ester, 12-myristate 13-acetate, synthetic diacylglycerol, oleoyl acetylglycerol, stimulated peptides, protein (PKC) sufficient active phosphorylation. However, PKC inhibitor, staurosporine, down-regulation activity prolonged exposure esters completely inhibited PMA but In conclusion, AVP enhances at least two PKC-dependent PKC-independent. Although may enhance phosphorylation, necessary primary route agents act. At one pathways shared with EGF, only intermediates factors also perhaps kinases phosphorylate intermediates.