Neuromedin B receptor (BB1) and Gastrin-releasing peptide receptor (BB2) (BB1 (NMBR), BB2 (GRPR))

Bombesin receptors are a group of membrane-bound GPCRs crucial for mediating the effects of bombesin-like peptides, including neuromedin B and gastrin-releasing peptide. BB1 (NMB receptor) and BB2 (GRP receptor) are widely distributed in the central nervous system and peripheral tissues, participating in diverse physiological functions such as regulation of growth, gastrointestinal motility, hormone secretion, and CNS activities. They are strongly implicated in cancer biology due to frequent overexpression in tumors, making them important diagnostic and therapeutic targets for oncology and imaging. BB2, specifically, is referred to as the gastrin-releasing peptide receptor and is known for its role in tumor growth and small intestinal mucosal defense.

Other names

BB1 receptor (Neuromedin B receptor, NMB receptor)BB2 receptor (Gastrin-releasing peptide receptor, GRPR)Bombesin receptor subtypesGRP receptor (for BB2)

Antagonists: block endogenous peptide binding, inhibit receptor-mediated mitogenic signaling in tumors. Agonists: activate receptor signaling—used experimentally or for imaging. Cytotoxic conjugates: deliver cytotoxic payloads specifically to cells expressing BB1/BB2.