Neurotensin receptor 1 and Neurotensin receptor 2 (NTSR1 and NTSR2)

Neurotensin receptor 1 (NTSR1) and Neurotensin receptor 2 (NTSR2) are G protein-coupled receptors (GPCRs) that mediate the biological effects of neurotensin, a 13-amino-acid neuropeptide acting as both neurotransmitter and hormone. NTSR1 is the high-affinity receptor responsible for the classic neurotensin effects in the central nervous system and periphery, including modulation of dopamine signaling, analgesia, and gut regulatory functions. NTSR2 is a low-affinity receptor with high homology to NTSR1 and contributes to distinct, cell- and tissue-specific signaling, including protective effects in pancreatic beta cells and partial modulation of neurotensin's trophic actions. Both receptors are being explored as therapeutic targets, especially for cancers, obesity, neurodegenerative conditions, and metabolic diseases. Their molecular pharmacology includes complex signaling cascades involving kinases, second messengers, and transcription factors, making them important nodes for pharmacological intervention and biomarker discovery.

Other names

Neurotensin receptor type 1 (NTSR1)Neurotensin receptor type 2 (NTSR2)High affinity neurotensin receptor (NTSR1)Low affinity neurotensin receptor (NTSR2)Sometimes referenced with organism prefix, e.g. "Human neurotensin receptor 1"

NTSR1: Activation of phospholipase C-γ (PLC-γ), IP3/DAG production, intracellular Ca⁺² mobilization, PKC and MAPK-ERK1/2 pathway activation, promoting cell survival and proliferation. NTSR2: Similar pathways, but less well characterized; involvement in [Ca⁺²] mobilization, ERK phosphorylation, and beta cell protection. Antagonists: Block neurotensin binding and downstream signaling; used for anti-proliferative effects in cancer and other modulation.