Genetic encoding of a nonhydrolyzable phosphotyrosine analog in mammalian cells.

Protein tyrosine phosphorylation plays a critical role in signal transduction. We report the genetic incorporation of a phosphotyrosine (pTyr) analog, p -carboxymethyl-L-phenylalanine (CMF), into proteins in mammalian cells. This nonhydrolyzable pTyr analog can facilitate biological studies by removing complications caused by the dynamic interconversion between the phosphorylated and non-phosphorylated isoforms of a protein.