Phosphatidylinositol-specific phospholipase C across biological kingdoms: domain organization, functions and regulation

Phospholipase C (PLC) plays crucial roles in phospholipid metabolism by generating second messengers regulating diverse cellular processes. PLCs are classified into phosphatidylinositol-specific PLCs (PI-PLCs) and nonspecific PLCs. Among them, PI-PLCs are highly conserved across mammals, plants and bacteria, with distinct structural organizations and regulatory mechanisms. Mammalian PI-PLCs participate in intracellular signalling and modulate various pathways, such as the G protein-coupled receptor- and receptor tyrosine kinase-mediated cascades, whereas plant PI-PLCs regulate the growth and stress responses via phosphatidic acid and inositol phosphate signalling. Bacterial PI-PLCs contribute to virulence by targeting the host cell membranes and glycosylphosphatidylinositol-anchored proteins. Despite structural variations, PI-PLCs share conserved catalytic mechanisms integral to cellular physiology across different organisms. This review article highlights the structural diversity and functional significance of PI-PLCs in mammals, plants and bacteria.