title: Structure and diversity of the murine cryptdin gene family.
abstract: Cryptdins are antimicrobial peptides of the defensin family produced by mouse intestinal Paneth cells. Characterization of genomic and cDNA clones of cryptdins 1-3, 5, and 6 revealed that each of these genes has a two-exon structure. The prepro- and mature peptide coding regions are found on different exons separated by an intron of approximately 550 bp. The 5' ends of cryptdin mRNAs are distinguished by a 45-nucleotide untranslated sequence (UTS) encoded completely by the first exon. This feature contrasts with the extended 5' UTS of myeloid defensin mRNAs, which are coded by a third exon that appears to be unique to defensin genes expressed in hematopoietic cells. Sequencing of cryptdin cDNAs from both C3H/HeJ and 129/SVJ mouse small intestine demonstrated the presence of at least 16 different mRNAs, identifying cryptdins as the largest known defensin family. Amplification of these two-exon crypt defensin genes, followed by mutation-induced divergence at a limited number of positions, may have played an important role in the development of a broad-spectrum enteric defense system in the mouse.
authors.affiliation: Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts.
authors.forename: K M
authors.initials: KM
authors.lastname: Huttner
authors.forename: M E
authors.initials: ME
authors.lastname: Selsted
authors.forename: A J
authors.initials: AJ
authors.lastname: Ouellette
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics; D003062:Codon; D018076:DNA, Complementary / Q000235:genetics; D023082:Defensins; D005091:Exons; D005786:Gene Expression Regulation; D005796:Genes; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D051379:Mice / Q000235:genetics*; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D005810:Multigene Family; D009928:Organ Specificity; D011498:Protein Precursors / Q000145:classification / Q000235:genetics*; D011506:Proteins / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001798:Blood Proteins; D003062:Codon; D018076:DNA, Complementary; D023082:Defensins; D011498:Protein Precursors; D011506:Proteins; C059569:cryptdin