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Gene Review

Defa20  -  defensin, alpha, 20

Mus musculus

Synonyms: 2010016F14Rik, Alpha-defensin 20, Cryptdin-4, Defcr20, Defensin-related cryptdin-20
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Disease relevance of Defcr20

  • Colorimetric and tryptophan fluorescence studies showed that Crp4 insertion is favored by negatively charged phospholipids and that zwitterionic and Escherichia coli phospholipids promote stronger interfacial binding; melittin-membrane interactions were independent of either variable [1].
  • We report here that the extracytoplasmic sigma factor sigma(E) (RpoE) is required for Salmonella resistance to killing by the bactericidal/permeability-increasing protein (BPI)-derived peptide P2 and the murine alpha-defensin cryptdin-4 (Crp4) [2].
  • Four antimicrobial peptides, protegrin-1, RTD-1, cryptdin-4, and indolicidin, were tested for their ability to inhibit the in vitro growth of Chlamydia trachomatis serovars E, L2, and mouse pneumonitis (MoPn) [3].

High impact information on Defcr20

  • The mouse cryptdin-4 gene is expressed with positional specificity along the longitudinal intestinal axis, and cryptdin genes are active in the intestinal epithelium prior to Paneth cell differentiation [4].
  • We report here the NMR solution structures of the mouse Paneth cell alpha-defensin cryptdin-4 (Crp4) and a mutant (E15D)-Crp4 peptide, in which a conserved Glu(15) residue was replaced by Asp [5].
  • Thus, Arg residues function as determinants of Crp4 bactericidal activity by facilitating or enabling target cell membrane disruption [6].
  • Paneth cells secrete microbicidal enteric alpha-defensins into the small intestinal lumen, and cryptdin-4 (Crp4) is the most bactericidal of the mouse alpha-defensin peptides in vitro [6].
  • In a series of Crp4 disulfide variants whose cysteine connectivities were confirmed using NMR spectroscopy and mass spectrometry, mutagenesis did not induce loss of function [7].

Chemical compound and disease context of Defcr20

  • The microbicidal activities of recombinant cryptdin-4 and (des-Gly)-cryptdin-4 peptides against E. coli, and S. typhimurium showed that the N-terminal Gly residue or the length of the cryptdin-4 N terminus are determinants of microbicidal activity [8].

Biological context of Defcr20


Anatomical context of Defcr20

  • Of the known Paneth cell alpha-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) [9].
  • In an agar diffusion assay, the potencies of cryptdins 1 to 3, 5, and 6 were approximately equivalent to that of rabbit neutrophil defensin NP-1 but cryptdin 4 was 30 times more active than NP-1 [10].
  • 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 [9].
  • Quantitative interactions between cryptdin-4 amino terminal variants and membranes [11].
  • By peptide-specific reverse transcriptase-polymerase chain reaction-based assays, cryptdin-4 mRNA was found to be absent from the proximal small bowel, increasing to maximal levels in the ileum [12].

Associations of Defcr20 with chemical compounds

  • Structure-activity determinants in paneth cell alpha-defensins: loss-of-function in mouse cryptdin-4 by charge-reversal at arginine residue positions [6].
  • To test whether this invariant structural feature determines alpha-defensin bactericidal activity, mouse cryptdin-4 (Crp4) tertiary structure was disrupted by pairs of site-directed Ala for Cys substitutions [7].
  • Formate enhances bacterial resistance to P2, as previously demonstrated, but not to Crp4 [2].


  1. Interactions of mouse Paneth cell alpha-defensins and alpha-defensin precursors with membranes. Prosegment inhibition of peptide association with biomimetic membranes. Satchell, D.P., Sheynis, T., Shirafuji, Y., Kolusheva, S., Ouellette, A.J., Jelinek, R. J. Biol. Chem. (2003) [Pubmed]
  2. The alternative sigma factor sigma is required for resistance of Salmonella enterica serovar Typhimurium to anti-microbial peptides. Crouch, M.L., Becker, L.A., Bang, I.S., Tanabe, H., Ouellette, A.J., Fang, F.C. Mol. Microbiol. (2005) [Pubmed]
  3. Susceptibility of human and murine Chlamydia trachomatis serovars to granulocyte- and epithelium-derived antimicrobial peptides. Chong-Cerrillo, C., Selsted, M.E., Peterson, E.M., de la Maza, L.M. J. Pept. Res. (2003) [Pubmed]
  4. Paneth cell defensins: endogenous peptide components of intestinal host defense. Ouellette, A.J., Selsted, M.E. FASEB J. (1996) [Pubmed]
  5. Structural and Functional Characterization of the Conserved Salt Bridge in Mammalian Paneth Cell {alpha}-Defensins: SOLUTION STRUCTURES OF MOUSE CRYPTDIN-4 AND (E15D)-CRYPTDIN-4. Rosengren, K.J., Daly, N.L., Fornander, L.M., Jönsson, L.M., Shirafuji, Y., Qu, X., Vogel, H.J., Ouellette, A.J., Craik, D.J. J. Biol. Chem. (2006) [Pubmed]
  6. Structure-activity determinants in paneth cell alpha-defensins: loss-of-function in mouse cryptdin-4 by charge-reversal at arginine residue positions. Tanabe, H., Qu, X., Weeks, C.S., Cummings, J.E., Kolusheva, S., Walsh, K.B., Jelinek, R., Vanderlick, T.K., Selsted, M.E., Ouellette, A.J. J. Biol. Chem. (2004) [Pubmed]
  7. Functional analysis of the alpha-defensin disulfide array in mouse cryptdin-4. Maemoto, A., Qu, X., Rosengren, K.J., Tanabe, H., Henschen-Edman, A., Craik, D.J., Ouellette, A.J. J. Biol. Chem. (2004) [Pubmed]
  8. Characterization of luminal paneth cell alpha-defensins in mouse small intestine. Attenuated antimicrobial activities of peptides with truncated amino termini. Ouellette, A.J., Satchell, D.P., Hsieh, M.M., Hagen, S.J., Selsted, M.E. J. Biol. Chem. (2000) [Pubmed]
  9. Peptide localization and gene structure of cryptdin 4, a differentially expressed mouse paneth cell alpha-defensin. Ouellette, A.J., Darmoul, D., Tran, D., Huttner, K.M., Yuan, J., Selsted, M.E. Infect. Immun. (1999) [Pubmed]
  10. Mouse Paneth cell defensins: primary structures and antibacterial activities of numerous cryptdin isoforms. Ouellette, A.J., Hsieh, M.M., Nosek, M.T., Cano-Gauci, D.F., Huttner, K.M., Buick, R.N., Selsted, M.E. Infect. Immun. (1994) [Pubmed]
  11. Quantitative interactions between cryptdin-4 amino terminal variants and membranes. Satchell, D.P., Sheynis, T., Kolusheva, S., Cummings, J., Vanderlick, T.K., Jelinek, R., Selsted, M.E., Ouellette, A.J. Peptides (2003) [Pubmed]
  12. Positional specificity of defensin gene expression reveals Paneth cell heterogeneity in mouse small intestine. Darmoul, D., Ouellette, A.J. Am. J. Physiol. (1996) [Pubmed]
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