Gene superfamily: defensins; (DEFA1 DEFA4 DEFA5 DEFA6 DEFB1 DEFB2)


SUM

Defensins are antimicrobial/antiviral peptides that participate in innate host defence. Certain defensins are expressed in neutrophils (macrophages), while others are expressed in Paneth cells (secretory epithelial cells of the small intestinal crypts). Defensins are 29 to 34 residues in length and are characterized by a specific spatial array of six cysteines forming intramolecular disulfide bonds. Three of the human defensins (1, 2 and 3) are almost identical in sequence and the most of the investigators (see for reviews Lehrer-1991, Boman-1995) consider that all of them are encoded by one gene (GEM:08p23/DEFA1). However, there is a conflicting report that defensins 1, 2 and 3 are encoded by different (at least two) genes (Mars-1995). Moreover the authors conclude that individuals can inherit versions of Chr 8 harboring either two or three copies of the genes that encode the defensin-1, -2, and/or -3."

REF

REV,FUN,EVO "Boman HG &: Annu Rev Immunol, 13, 61-92, 1995
REV,FUN,EVO "Lehrer RI &: Annu Rev Immunol, 11, 105-128, 1993
REV,FUN "Lehrer RI &: Cell, 64, 229-230, 1991
GEN,EVO,FAG,SUM "Mars WM &: JBC, 270, N51, 30371-30376, 1995