Phosphoinositide kinases and phospholipases (PIKs/PLCs)

Phosphoinositide kinases and phospholipases are a broad class of enzymes that orchestrate the metabolism of phosphoinositides, which are critical lipid signaling molecules in eukaryotic cells. Phosphoinositide kinases, such as the well-studied Phosphoinositide 3-kinases (PI3Ks), catalyze the phosphorylation of the inositol ring to generate docking sites for proteins that regulate cell survival, growth, and metabolism (UniProt, 2023). Phospholipases, including Phospholipase C (PLC) and Phospholipase A2 (PLA2), catalyze the hydrolysis of these lipids into secondary messengers like inositol trisphosphate (IP3) and arachidonic acid, which mediate calcium signaling and inflammatory pathways (PubMed, 2021). Dysregulation of these enzymatic activities is a major driver in various diseases; for instance, mutations in PIK3CA are among the most common genetic alterations in human cancers (NIH, 2022). Additionally, overactive phospholipases are implicated in chronic inflammatory conditions and cardiovascular diseases. Due to their central roles in signal transduction, these enzymes are significant therapeutic targets, with several PI3K inhibitors like Alpelisib and Idelalisib currently approved for clinical use (PubChem, 2024). However, targeting these pathways presents challenges, including the management of off-target effects like hyperglycemia and the development of drug resistance. Overall, this group of enzymes remains a cornerstone of modern drug discovery efforts in oncology and immunology.

Other names

Phosphoinositide-metabolizing enzymesPI-metabolizing enzymesPhosphoinositide signaling enzymes

Inhibition of phosphoinositide phosphorylation by kinases or inhibition of phosphoinositide hydrolysis by phospholipases to modulate downstream signaling cascades such as the PI3K/AKT/mTOR or PLC/IP3/DAG pathways.