Phospholipase C

File:PLC Signaling.jpeg

PLC Signaling

Phospholipases2

Comparison of C2 domain of mammalian PI-PLC in red and C2-like domain of Bacillus cereus in cyan

General reaction catalyzed by phospholipase C

File:PLC Signaling.jpeg

PLC Signaling

PLC role in IP3-DAG pathway

== Phospholipase C ==

Phospholipase C (PLC) is a class of enzymes that play a crucial role in the phosphoinositide signaling pathway. These enzymes are responsible for the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into two important secondary messengers: diacylglycerol (DAG) and inositol trisphosphate (IP3).

Structure and Isoforms[edit | edit source]

Phospholipase C enzymes are divided into several isoforms, including PLC-β, PLC-γ, PLC-δ, PLC-ε, PLC-ζ, and PLC-η. Each isoform has a unique structure and function, and they are activated by different mechanisms. For example, PLC-β is activated by G protein-coupled receptors, while PLC-γ is activated by receptor tyrosine kinases.

Mechanism of Action[edit | edit source]

Upon activation, PLC hydrolyzes PIP2, a phospholipid found in the inner leaflet of the plasma membrane. This reaction produces two secondary messengers:

Diacylglycerol (DAG): Remains in the membrane and activates protein kinase C (PKC), which is involved in various cellular processes such as cell proliferation, differentiation, and apoptosis.
Inositol trisphosphate (IP3): Diffuses through the cytoplasm and binds to IP3 receptors on the endoplasmic reticulum, causing the release of calcium ions into the cytoplasm. This increase in intracellular calcium concentration triggers various cellular responses, including muscle contraction, secretion, and metabolism.

Biological Functions[edit | edit source]

Phospholipase C enzymes are involved in a wide range of biological processes, including:

Clinical Significance[edit | edit source]

Dysregulation of PLC activity has been implicated in various diseases, including cancer, cardiovascular diseases, and neurological disorders. For instance, overexpression of certain PLC isoforms has been observed in some types of cancer, making them potential targets for therapeutic intervention.