Tyrosine phosphorylation of mitogen-activated protein kinase in cells with tyrosine kinase-negative epidermal growth factor receptors

• Published in: The Journal of biological chemistry 1992-07, Vol.267 (21), p.14535-14538
• Main Authors: R Campos-González, J R Glenney, Jr
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blotting, Western; Calcium-Calmodulin-Dependent Protein Kinases; Cell physiology; Cells, Cultured; Enzyme Activation; epidermal growth factor; ErbB Receptors - metabolism; Fundamental and applied biological sciences. Psychology; mitogen-activated protein kinase; Mitogens; Molecular and cellular biology; Phosphorylation; Protein Kinases - metabolism; receptors; requirements; Responses to growth factors, tumor promotors, other factors; tyrosine; Tyrosine - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)42070-4

Epidermal growth factor (EGF) treatment of cells expressing the human EGF receptor (EGFr) results in rapid tyrosine phosphorylation of several cellular proteins including mitogen-activated protein (MAP) kinase. EGF treatment of cells expressing a tyrosine kinase-inactive EGFr failed to induce the tyrosine phosphorylation of endogenous substrates in response to EGF; however, the tyrosine phosphorylation and activation of MAP kinase did occur. This observation indicates that MAP kinase is activated in response to a signal other than the tyrosine kinase activity of the EGFr. Because EGF does not stimulate cells expressing the inactive EGFr to proliferate, phosphorylation of MAP kinase may not be sufficient for the EGF-dependent mitogenesis.