Abstract
A property of signal transduction pathways that might explain their efficiency and specificity is the formation of signaling complexes. The recent demonstration that adaptor proteins can interact with many components of the extracellular signal-regulated kinases (ERKs) signaling cascade leads us to investigate whether such complexes may include the transmembrane receptor. The present work shows that in human hepatoma Hep3B cells, insulin receptor (IR) can be coimmunoprecipitated with other components of the ERKs cascade: insulin receptor substrate (IRS), Raf-1, and ERKs. Furthermore, these complexes formed near the cytoplasmic membrane even prior to insulin stimulation.
Copyright 2001 Academic Press.
MeSH terms
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Blotting, Western
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Carcinoma, Hepatocellular / chemistry
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Carcinoma, Hepatocellular / metabolism
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Humans
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Macromolecular Substances
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Mitogen-Activated Protein Kinase 1 / analysis
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Mitogen-Activated Protein Kinase 1 / metabolism
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases / analysis
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Mitogen-Activated Protein Kinases / metabolism*
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Phosphorylation
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Precipitin Tests
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Proto-Oncogene Proteins c-raf / analysis
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Proto-Oncogene Proteins c-raf / metabolism
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Receptor, Insulin / analysis
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Receptor, Insulin / metabolism*
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Signal Transduction / physiology
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Tumor Cells, Cultured
Substances
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Macromolecular Substances
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Receptor, Insulin
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Proto-Oncogene Proteins c-raf
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases