Docking Protein 2 (DOK2)

Docking protein 2 is constitutively tyrosine phosphorylated in hematopoietic progenitors isolated from chronic myelogenous leukemia (CML) patients in the chronic phase. It may be a critical substrate for p210(bcr/abl), a chimeric protein whose presence is associated with CML. This encoded protein binds p120 (RasGAP) from CML cells.The DOK2 cDNA clone encodes a 412-amino acid protein with a molecular mass of 53 to 56 kD. The DOK2 protein has a potential pleckstrin homology (PH) domain at the N terminus, 13 potential tyrosine phosphorylation sites, 6 PXXP motifs, and 2 YXXPXD motifs (predicted Ras-GAP SH2 domain binding sites). It shares 34.8% overall amino acid identity with another tyrosine-phosphorylated protein, p62dok (DOK1), which also contains a predicted PH domain at its N terminus.