Hepatic tyrosine-phosphorylated proteins identified and localized following in vivo inhibition of protein tyrosine phosphatases: effects of H2O2 and vanadate administration into rat livers

摘要: Abstract Injection of a combination H 2 O and vanadate (H/V) into the portal vein rat livers resulted in inhibition protein tyrosine phosphatase activity led to dramatic enhanced vivo phosphorylation. Some phosphorylated proteins were identified as β-subunit insulin receptor, receptor substrate 1 (ppl85), PLC-γ (pp145), 100 kDa PLC-γ-associated protein. Immunofluorescense immune electron microscopy frozen liver sections with anti-P-Tyr antibodies revealed that most tyrosine-phosphorylated are localized close proximity plasma membrane intercellular adherence junctions tight junction regions. This association between membranal kinases, their target proteins, cytoskeletal elements could enable formation ‘signaling complexes’ which may play role transmembrane signal transduction. By affinity chromatography over immobilized antibodies, large number these partially purified.