Neurokinin-2 Receptor (NK2R)

The Neurokinin-2 receptor (NK2R), also known as the tachykinin receptor 2 or substance K receptor, is a G protein-coupled receptor (GPCR) that primarily binds the neuropeptide neurokinin A (NKA). It mediates various physiological processes including smooth muscle contraction, regulation of inflammation, and pain transmission. NK2Rs are expressed on various cell types including neurons within both central and peripheral nervous systems, immune cells (macrophages, mast cells, T lymphocytes). Dysregulation of NK2Rs has been implicated in chronic airway diseases and inflammatory disorders. Several antagonists have undergone clinical trials for indications like IBS and depression but have not reached approval due to insufficient efficacy or adverse outcomes.

Other names

Tachykinin Receptor 2Substance K Receptor

Agonist: activation of G proteins leading to activation of phospholipase C and downstream signaling involving MAPK/ERK pathway, mTOR signaling cascade, and modulation of cytokine expression via transcription factors like AP‑1 and NF‑κB. Antagonist: blockade of receptor activation by endogenous ligand.