title: The human neurokinin A (substance K) receptor. Molecular cloning of the gene, chromosome localization, and isolation of cDNA from tracheal and gastric tissues.
abstract: Neurokinin A (substance K) is a peptide neurotransmitter of the tachykinin family with potential as a major mediator in human airway and gastrointestinal tissues. Neurokinin A acts via a receptor (the NK-2 receptor) believed to be localized on smooth muscle cells and pharmacologically coupled to a GTP-binding protein. To characterize the human NK-2 receptor, we prepared a partial cDNA from human tracheal RNA using the polymerase chain reaction with oligonucleotide primers derived from the bovine NK-2 receptor cDNA sequence (Masu, Y., Nakayama, K., Tamaki, H., Harada, Y., Kuno, M., Nakanishi, S. (1987) Nature 329, 836-838). This partial human NK-2 receptor cDNA was used to screen a human genomic DNA library and yielded a clone, NGNK-2, of approximately 25 kilobases. Analysis of NGNK-2 indicates that it contains the entire coding sequence of the NK-2 receptor as well as 5'- and 3'-flanking sequences. The gene is organized with five exons interrupted by four introns. The complete sequence of the exons and the intron-exon junctions was determined, as were the transcription initiation site and the 3'-polyadenylation signal. Analysis of EcoRI digests of genomic DNA from human-mouse cell hybrids indicates a single gene for the human NK-2 receptor localized to chromosome 10. Sequence analysis of exons 1 and 5, where major differences occur between the human and animal species, provided information for polymerase chain reaction primers which allowed us to prepare full-length cDNA for the human NK-2 receptor. The protein predicted from the gene sequence is extended by 14 amino acids at the COOH terminus compared to the bovine and 9 residues compared to the rat molecules. The seven membrane-spanning regions are encoded by exons 1-4 and none is interrupted by introns. These regions are highly conserved among the species studied, suggesting stringent evolutionary control over these molecules.
authors.affiliation: Department of Medicine, Beth Israel Hospital, Boston, Massachusetts.
authors.forename: N P
authors.initials: NP
authors.lastname: Gerard
authors.forename: R L
authors.initials: RL
authors.lastname: Eddy
authors.forename: T B
authors.initials: TB
authors.lastname: Shows
authors.forename: C
authors.initials: C
authors.lastname: Gerard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002874:Chromosome Mapping; D002879:Chromosomes, Human, Pair 10; D003001:Cloning, Molecular / Q000379:methods; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005091:Exons; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D015723:Gene Library; D006801:Humans; D006822:Hybrid Cells / Q000378:metabolism; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism*; D015288:Neurokinin A / Q000378:metabolism; D015345:Oligonucleotide Probes; D010920:Placenta / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000235:genetics*; D015183:Restriction Mapping; D014132:Trachea / Q000378:metabolism*
chemical_list: D015345:Oligonucleotide Probes; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D015288:Neurokinin A; D004247:DNA