A novel mitogenic protein that is highly expressed in cells of the gastric antrum mucosa.
Human and pig cDNAs for a novel stomach protein, the product of a gene expressed at high levels specifically in cells of the antrum mucosa, have been characterized. The general exon/intron structure of the genomic DNA is conserved in humans and mice. The predicted protein sequences of the human and mouse mRNAs contain 185 and 184 amino acids, respectively. The protein isolated from pig antral extracts has an NH2 terminus consistent with cleavage of a 20-amino acid signal peptide. Human cDNA was expressed in E. coli to generate a protein antigen for antibody production. The antibodies detected polypeptides of approximately 18 kDa in antrum extracts from all mammalian species tested. Immunocytochemistry located antrum mucosal protein (AMP)-18 to surface mucosal cells of the mouse antrum and, specifically, to secretion granules, suggesting that it is cosecreted with mucins. Antrum extracts and recombinant human AMP-18 exhibit growth-promoting activity on epithelial cells that can be blocked by the specific antisera. We suggest that AMP-18 is a "gastrokine" that maintains the integrity of the gastric mucosal epithelium.
Martin
Terence E
TE
Dept. of Molecular Genetics and Cell Biology, The Univ. of Chicago, IL 60637, USA. tema@midway.uchicago.edu
Powell
C Thomas
CT
Wang
Zunde
Z
Bhattacharyya
Somnath
S
Walsh-Reitz
Margaret M
MM
Agarwal
Kan
K
Toback
F Gary
FG
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000737:chemistry; D004847:Epithelial Cells / Q000187:drug effects; D004926:Escherichia coli / Q000235:genetics; D005091:Exons; D005753:Gastric Mucosa / Q000737:chemistry*; D015870:Gene Expression; D006801:Humans; D007438:Introns; D051379:Mice; D008934:Mitogens / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D008969:Molecular Sequence Data; D036361:Peptide Hormones; D010455:Peptides; D011706:Pyloric Antrum / Q000737:chemistry*; D012333:RNA, Messenger / Q000737:chemistry; D011994:Recombinant Proteins / Q000494:pharmacology; D016415:Sequence Alignment; D013552:Swine; D014020:Tissue Extracts / Q000494:pharmacology; D014162:Transfection
D018076:DNA, Complementary; C477000:GKN1 protein, human; D008934:Mitogens; D036361:Peptide Hormones; D010455:Peptides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014020:Tissue Extracts