Activated SRC phosphorylates RUNX3 in the cytosol, on multiple tyrosine residues. There are eleven tyrosine residues in RUNX3, but SRC target sites have not been determined. SRC-mediated phosphorylation of RUNX3 inhibits translocation of RUNX3 to the nucleus and is the underlying cause of cytosolic localization of RUNX3 in gastric and breast cancer (Goh et al. 2010).
protein tyrosine kinase activity of MyrG-p-Y419-SRC:RUNX3 [plasma membrane]