Figure 4

NEAP dephosphorylates TrkA and FGFR1 directly. (a) Activating loop sequences of EGFR, FGFR1, FGFR2, IGFR1, INSR, TrkA, and TrkB were aligned using the Clustal Omega and Boxshade programs. Identical and homologous amino acid residues were shown by black and grey shades, respectively. Dual Tyr-phosphorylation sites were indicated by bold asterisks. EGFR Tyr 845 was indicated by an asterisk. (b) Flag-tagged pTrkA was immune-precipitated from transfected H1299 cells and was subjected to NEAP dephosphorylation with or without the GST-AK2 presence. The levels of pTrkA/TrkA in the reaction mixtures were examined by immune-blotting using indicated antibodies. (c and d) Rat FGFR1 and IGFR1 were immunoprecipitated from PC12 cells and subjected to NEAP dephosphorylation in the presence or absence of GST-AK2. The levels of pFGFR1/FGFR1 (panel c) and pIGFR1/IGFR1 (panel d) in the reaction mixtures were examined by immune-blot analyses using indicated antibodies.