Gq11signalväg

Gq11signalväg, also known as the Gq11 signaling pathway, is a crucial cellular communication mechanism involved in a variety of physiological processes. This pathway is initiated when a G protein-coupled receptor (GPCR) binds to its extracellular ligand. Upon ligand binding, the GPCR undergoes a conformational change, leading to the activation of a heterotrimeric G protein, specifically one of the Gq family, Gq11 being a prominent member.

The activated Gq11 protein then dissociates its alpha subunit, Gαq11, from the beta-gamma subunits. The Gαq11 subunit, in turn, activates a downstream enzyme called phospholipase C-beta (PLCβ). PLCβ hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2), a membrane phospholipid, into two second messengers: inositol trisphosphate (IP3) and diacylglycerol (DAG).

IP3 then diffuses to the endoplasmic reticulum, where it binds to IP3 receptors, causing the release of stored calcium ions (Ca2+) into the cytoplasm. This increase in intracellular calcium is a critical signaling event that can activate various calcium-dependent enzymes and proteins. Simultaneously, DAG remains in the plasma membrane and, along with the elevated intracellular calcium, activates protein kinase C (PKC). PKC then phosphorylates a wide array of target proteins, modulating their activity and ultimately influencing cellular responses such as gene expression, cell proliferation, and secretion. The Gq11 pathway plays roles in sensory perception, hormonal signaling, and smooth muscle contraction, among other functions.