NMB

Overview

NMB is a decapeptide which was originally isolated from porcine spinal cord [1] and is the mammalian equivalent of the frog peptide ranatensin, to which it has an almost identical... [read more] COOH terminus with six of seven amino acid identities [2]. The location of the human NMB gene is chromosome 15q11 [3,4]. NMB is encoded as a prepro-NMB, a 76 amino acid precursor that consists of a 24 amino acid signal peptide, NMB-32 and a 17 amino acid carboxyl terminal extension peptide [3]. The predicted amino acid sequence for NMB-32 is highly conserved in human, rat and pig with only differences of four amino acids [2,5]. The NMB gene is encoded in three exons and studies on rat and human genomic DNA are consistent with only a single NMB gene present. In the human Northern blot analysis reveals high expression in the hypothalamus, colon, stomach and low levels in the pancreas, cerebellum and adrenals [2]. By in situ hybridization studies NMB mRNA was found in rat brain in the greatest amounts in the olfactory bulb, dentate gyrus and dorsal root ganglion [5]. NMB has a wide range of physiological and pharmacological effects and these will be discussed later.

References

1. Minamino N, Kangawa K, Matsuo H. Neuromedin B: a novel bombesin-like peptide identified in porcine spinal cord. Biochem Biophys Res Commun 1983;114:541-548.
2. Ohki-Hamazaki H. Neuromedin B. Prog Neurobiol 2000;62:297-312.
3. Krane IM, Naylor SL, Helin-Davis D, et al. Molecular cloning of cDNAs encoding the human bombesin-like peptide neuromedin B. Chromosomal localization and comparison to cDNAs encoding its amphibian homolog ranatensin. J Biol Chem 1988;263:13317-23.
4. Gregory CA, Schwartz JS. The cDNA of the human neuromedin B gene (NMB) mapped to 15q11-qter recognizes an XbaI RFLP. Nucleic Acids Res 1991;19:1167.
5. Wada E, Way J, Lebacq-Verheyden AM, et al. Neuromedin B and gastrin-releasing peptide mRNAs are differentially distributed in the rat nervous system. J Neurosci 1990;10:2917-2930.

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