G protein-coupled neurotensin receptor activity

Definition

Target type: molecularfunction

Combining with the tridecapeptide neurotensin to initiate a G-protein mediated change in cell activity. A G-protein is a signal transduction molecule that alternates between an inactive GDP-bound and an active GTP-bound state. [PMID:10390649]

G protein-coupled neurotensin receptor activity involves the binding of neurotensin, a neuropeptide, to its cognate receptor, the neurotensin receptor 1 (NTS1). This binding triggers a series of molecular events, ultimately leading to downstream signaling cascades and cellular responses.

Firstly, neurotensin, upon binding to NTS1, induces a conformational change in the receptor's structure. This change activates the receptor's intracellular domain, which then interacts with intracellular signaling molecules.

One of the key signaling pathways activated by NTS1 is the G protein pathway. The activated receptor interacts with heterotrimeric G proteins, specifically the Gq/11 subtype. This interaction leads to the dissociation of the G protein α subunit from the βγ subunits.

The activated Gα subunit then stimulates phospholipase C (PLC) enzyme, which hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3). DAG activates protein kinase C (PKC), while IP3 triggers the release of calcium ions (Ca2+) from intracellular stores.

The increase in intracellular Ca2+ concentration and activation of PKC lead to a cascade of downstream signaling events, including activation of various kinases and transcription factors, ultimately modulating cellular processes such as neuronal excitability, neurotransmitter release, and cell growth.

The G protein-coupled neurotensin receptor activity is also associated with the activation of other signaling pathways, such as the mitogen-activated protein kinase (MAPK) pathway and the phosphoinositide 3-kinase (PI3K) pathway. These pathways contribute to the diverse physiological roles of neurotensin, including its involvement in regulating appetite, stress response, pain perception, and immune function.'
"

Proteins (2)

Compounds (8)