Neuromedin B

Neuromedin B (NMB) is a bombesin-related peptide in mammals.^[1][2] It was originally purified from pig spinal cord, and later shown to be present in human central nervous system and gastrointestinal tract.^[3]

Sequence

The sequence of the C-terminal decapeptide is highly conserved across mammalian species: GNLWATGHFM-(NH2); this decapeptide is sometimes noted as neuromedin B, but it is more accurately described as neuromedin B 23-32. The sequence of neuromedin B (in rat) is: TPFSWDLPEPRSRASKIRVHPRGNLWATGHFM-(NH2).^[4] The (NH2) here indicates a post-translational modification -- alpha amidation of the carboxy terminus.

Function

Neuromedin regulates the following functions:

• exocrine and endocrine secretions
• cell growth
• body temperature
• blood pressure and glucose level
• sneezing^[5]

Neuromedin signaling pathway

NMB acts by binding to its high affinity cell surface receptor, neuromedin B receptor (NMBR). This receptor is a G protein-coupled receptor with seven transmembrane spanning regions, hence the receptor is also denoted as a 7-transmembrane receptor (7-TMR). Upon binding several intracellular signaling pathways are triggered (see Figure 2).

When NMB binds to its 7-TMR, the