1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-1 (PLCG1) (PLCG1)

1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-1, commonly known as PLCG1, is a critical signaling enzyme that catalyzes the conversion of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) into the second messengers inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) (UniProt P19174). This enzymatic reaction is typically triggered by the activation of receptor tyrosine kinases (RTKs) or the T-cell receptor (TCR) complex, which leads to the phosphorylation and activation of PLCG1 (PubMed: 25108444). The resulting IP3 induces the release of calcium from the endoplasmic reticulum, while DAG activates protein kinase C (PKC), together driving essential cellular processes such as proliferation, differentiation, and migration. In oncology, PLCG1 has gained significant attention due to the discovery of recurrent gain-of-function mutations, such as S345F, in cutaneous T-cell lymphomas and angiosarcomas (PubMed: 25503234, PubMed: 25204443). These mutations lead to constitutive activation of the PLC-gamma signaling pathway, promoting malignant cell survival and resistance to apoptosis. While direct small-molecule inhibitors of PLCG1 are primarily in the preclinical stage, the enzyme is considered a high-priority target for precision medicine in cancers harboring these specific mutations. However, therapeutic development must address the challenge of achieving selectivity over other PLC isoforms and managing potential side effects related to the enzyme's vital role in normal immune system homeostasis.

Other names

Phospholipase C-gamma-1PLC-gamma-1PLC1PLC-IIPhosphoinositide phospholipase C-gamma-1

Inhibition of the catalytic activity of PLCG1 to prevent the hydrolysis of PIP2 into IP3 and DAG, thereby blocking downstream calcium signaling and PKC activation.