| Among these molecules are the growth arrest and DNA damage protein 34 ( GADD 34 ) and the Src related protein tyrosine kinase Lyn . ^^^ Multiple isolates of GADD 34 and the related murine protein MyD 116 were identified as binding partners of Lyn in a yeast two hybrid screen . ^^^ The specific interaction was confirmed by in vitro association of GADD 34 with glutathione S transferase fusion proteins containing the Src Homology 3 ( SH 3 ) domain of Lyn , as well as coimmunoprecipitation of GADD 34 and Lyn from mammalian cells . ^^^ GADD 34 was tyrosine phosphorylated in vivo in a Lyn dependent manner . ^^^ Lyn efficiently phosphorylated affinity purified GADD 34 in vitro . ^^^ |