Phosphotyrosine 1173 mediates binding of the protein-tyrosine phosphatase SHP-1 to the epidermal growth factor receptor and attenuation of receptor signaling.
The protein-tyrosine phosphatase SHP-1 binds to and dephosphorylates the epidermal growth factor receptor (EGFR), and both SH2 domains of SHP-1 are important for this interaction (Tenev, T., Keilhack, H., Tomic, S., Stoyanov, B., Stein-Gerlach, M., Lammers, R., Krivtsov, A. V., Ullrich, A., and Böhmer, F. D. (1997) J. Biol. Chem. 272, 5966-5973). We mapped the EGFR phosphotyrosine 1173 as the major binding site for SHP-1 by a combination of phosphopeptide activation, phosphopeptide competition, and receptor YF mutant analysis. Mutational conversion of the EGFR sequence 1171-1176 AEYLRV into the high affinity SHP-1 binding sequence LEYLYL of the erythropoietin receptor (EpoR) led to a highly elevated SHP-1 binding to the mutant EGFR (EGFR1171-1176EpoR) and in turn to an enhanced dephosphorylation of the receptor. SHP-1 expression interfered with EGF-dependent mitogen-activated protein kinase stimulation, and this effect was more pronounced in case of EGFR1171-1176EpoR. Reduced SHP-1 binding to the EGFR Y1173F mutant resulted in a reduced receptor dephosphorylation by coexpressed SHP-1 and less interference with EGF-dependent mitogen-activated protein kinase stimulation. The effects of receptor mutations on SHP-1 binding were, however, stronger than those on receptor dephosphorylation by SHP-1. Therefore, receptor dephosphorylation may be the result of the combined activity of receptor-bound SHP-1 and SHP-1 bound to an auxiliary docking protein.
Keilhack
H
H
Research Unit "Molecular Cell Biology," Medical Faculty, Friedrich Schiller University, D-07747 Jena, Germany.
Tenev
T
T
Nyakatura
E
E
Godovac-Zimmermann
J
J
Nielsen
L
L
Seedorf
K
K
Böhmer
F D
FD
D000595:Amino Acid Sequence; D001665:Binding Sites; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002460:Cell Line; D003001:Cloning, Molecular; D066246:ErbB Receptors / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010748:Phosphopeptides / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D017354:Point Mutation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction; D014162:Transfection; D018909:src Homology Domains
D047908:Intracellular Signaling Peptides and Proteins; D010446:Peptide Fragments; D010748:Phosphopeptides; D011994:Recombinant Proteins; D019000:Phosphotyrosine; D066246:ErbB Receptors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C516724:PTPN11 protein, human; C509249:PTPN6 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases