Cloning and expression of the neuromedin B receptor and the third subtype of bombesin receptor genes in the mouse.
We cloned the genes for the mouse homologue of the neuromedin B receptor (NMB-R) and the bombesin receptor subtype 3 (BRS-3). Both receptor genes consist of three exons with well-conserved intron-exon borders. Although the NMB-R gene spans more than 10 kb, the BRS-3 gene spans only about 4 kb. Comparison of the mouse and human receptor sequences indicates 90% (NMB-R) and 85% (BRS-3) sequence homology at the amino-acid level. In the adult mouse, the NMB-R mRNA is expressed in the brain, testis, esophagus, intestine and uterus, whereas the BRS-3 mRNA is expressed predominantly in the brain. In the brain, the NMB-R gene expression is prominent in the thalamic and olfactory regions, and the BRS-3 gene is expressed particularly in the hypothalamic region. In mouse testis, the NMB-R gene expression is prominent, and the expression of BRS-3 mRNA is barely detected. In contrast, BRS-3 has been shown to be expressed in rat testis and guinea-pig uterus, therefore it is possible that a different subtype of the bombesin receptor mediates the same response in different species. Together with the mouse GRP-R gene cloned previously, cloning of the mouse NMB-R and BRS-3 genes permits comparison of function and structure of the three bombesin receptor subtypes in the mouse.
Ohki-Hamazaki
H
H
Department of Degenerative Neurological Diseases, National Institute of Neuroscience, NCNP, Kodaira, Tokyo, Japan. hamazaki@prit.go.jp
Wada
E
E
Matsui
K
K
Wada
K
K
D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry / Q000502:physiology; D003001:Cloning, Molecular; D016384:Consensus Sequence; D015870:Gene Expression / Q000502:physiology; D015723:Gene Library; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000032:analysis; D018004:Receptors, Bombesin / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000737:chemistry
D012333:RNA, Messenger; D018004:Receptors, Bombesin; C107120:bombesin receptor subtype 3