Autophosphorylation of FGFR1 kinase is mediated by a sequential and precisely ordered reaction.
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Furdui CM, Lew ED, Schlessinger J, Anderson KS
Autophosphorylation of FGFR1 kinase is mediated by a sequential and precisely ordered reaction.
Mol Cell. 2006 Mar 3;21(5):711-7.
- PubMed ID
- 16507368 [ View in PubMed]
- Abstract
Tyrosine phosphorylation of cellular proteins induced by extracellular cues serves as a critical mediator in the control of a great variety of cellular processes. Here, we describe an integrated experimental approach including rapid quench methodology and ESI-LC-MS/MS as well as time-resolved ESI-MS to demonstrate that tyrosine autophosphorylation of the catalytic tyrosine kinase domain of FGF-receptor-1 (FGFR1) is mediated by a sequential and precisely ordered reaction. We also demonstrate that the rate of catalysis of two FGFR substrates is enhanced by 50- to 100-fold after autophosphorylation of Y653 in the activation loop, whereas autophosphorylation of the second site in the activation loop (Y654) results in 500- to 1,000-fold increase in the rate of substrate phosphorylation. We propose that FGFR1 is activated by a two-step mechanism mediated by strictly ordered and regulated autophosphorylation, suggesting that distinct phosphorylation states may provide both temporal and spatial resolution to receptor signaling.