PLCG1's catalytic function can be activated by non-receptor tyrosine kinases, cytosolic enzymes responsible for catalyzing the transfer of phosphate group from a nucleoside triphosphate to tyrosine residues.
PLCG1 can be activated by receptor tyrosine kinases (RTKs) and non-receptor tyrosine kinases. The SH2 domains bind phosphorylated tyrosine residues on target proteins via their FLVR sequence motifs, activating the catalytic function of PLCg; and the SH3 domain binds to proline-rich sequences on the target protein. Non-receptor tyrosine kinases (nRTKs) are cytosolic enzymes that are responsible for catalysing the transfer of a phosphate group from a nucleoside triphosphate donor, such as ATP, to tyrosine residues in proteins. 
