Previous Article | Next Article ![]()
Infection and Immunity, December 1999, p. 6643-6651, Vol. 67, No. 12
Departments of Pathology1 and
Microbiology and Molecular Genetics,2
College of Medicine, University of California, Irvine, California
92697; Neuroendocrinologie et Biologie Cellulaire Digestives,
INSERM U410, Faculté de Médicine Xavier Bichat, 75018 Paris, France3; and Section on
Neonatology, Department of Pediatrics, Massachusetts General
Hospital, Boston, Massachusetts 021144
Received 11 June 1999/Returned for modification 26 July
1999/Accepted 17 September 1999
Paneth cells in crypts of the small intestine express antimicrobial
peptides, including
0019-9567/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Peptide Localization and Gene Structure of Cryptdin 4, a
Differentially Expressed Mouse Paneth Cell
-Defensin
-defensins, termed cryptdins in mice. Of the
known Paneth cell
-defensins, the cryptdin 4 gene is unique, because
it is inactive in the duodenum and expressed at maximal levels in the
distal small bowel (D. Darmoul and A. J. Ouellette, Am. J. Physiol. 271:G68-G74, 1996). With a cryptdin 4-specific antibody,
immunohistochemical staining of ileal Paneth cells was strong and
specific for cytoplasmic granules, demonstrating that this microbicidal
peptide is a secretory product of Paneth cells in the distal small
intestine. Consistent with the pattern of cryptdin 4 mRNA distribution
along the length of the gut, the cryptdin 4 peptide was not detected in
duodenum. Structurally, the cryptdin 4 gene resembles other Paneth cell
-defensin genes. Its two exons, transcriptional start site, intron,
splice sites, and 3' flanking sequences are characteristic of the
highly conserved mouse
-defensin genes. However, in the region
upstream of the transcriptional initiation site, the cryptdin 4 gene
contains a repeated 130-bp element that is unique to this
-defensin
gene. Every independent cryptdin 4 genomic clone examined carries the repeated element, which contains putative recognition sequences for
TF-IID-EIIA, cMyc-RS-1, and IgHC.2/CuE1.1; the repeat proximal to the
start of transcription replaces DNA at the corresponding position in
other mouse
-defensin genes. We speculate that this unique
duplicated element may have a cis-acting regulatory role in
the positional specificity of cryptdin 4 gene expression.
*
Corresponding author. Mailing address: Department of
Pathology, University of California College of Medicine, Irvine, CA
92697-4800. Phone: (949) 824-4647. Fax: (949) 824-1098. E-mail:
aouellet{at}uci.edu.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|