Antibody-induced dimerization of HARPTPalpha-EGFR chimera suggests a ligand dependent mechanism of regulation for RPTPalpha.
We developed a system to study the function of the ectodomain of RPTPalpha, a transmembrane protein-tyrosine phosphatase, by fusing the HA-epitope tagged ectodomain of RPTPalpha to the transmembrane and intracellular domain of the epidermal growth factor receptor, EGFR, a receptor protein-tyrosine kinase that is activated by dimerization. Although the use of chemical crosslinkers shows that preformed HARPTPalpha-EGFR dimers exist, bivalent anti-HA-tag antibody activated HARPTPalpha-EGFR chimeras, suggesting this system may be used to study regulation of dimerization. We used this system to show that newborn calf serum may contain (a) potential ligand(s) for RPTPalpha. Our results suggest that RPTPalpha dimerization and thus activity may be affected by ligand binding.
Blanchetot
C
C
Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands.
den Hertog
J
J
D000906:Antibodies / Q000494:pharmacology; D002460:Cell Line; D003432:Cross-Linking Reagents; D019281:Dimerization; D000939:Epitopes; D066246:ErbB Receptors / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014162:Transfection
D000906:Antibodies; D003432:Cross-Linking Reagents; D000939:Epitopes; D008024:Ligands; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D066246:ErbB Receptors; C516841:PTPRA protein, human; D017027:Protein Tyrosine Phosphatases; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4