DEFA4
Description
The DEFA4 (defensin alpha 4) is a protein-coding gene located on chromosome 8.
DEFA4 encodes a human defensin peptide, also known as neutrophil defensin 4 or HNP4, which is expressed in the granules of neutrophils. Defensins are a peptide family of cytotoxic microbicides involved in innate immunity, characterized by a conserved six-cysteine motif. Several human alpha defensin genes, including HNP4, are clustered on chromosome 8. DEFA4 differs from other defensin genes by an extra 83-base segment, likely due to a recent duplication within the coding region. HNP4 inhibits corticotropin-stimulated corticosterone production.
DEFA4 encodes a host-defense peptide with antimicrobial activity against Gram-negative bacteria, and to a lesser extent, Gram-positive bacteria and fungi. It exhibits antimicrobial activity against E. coli, E. aerogenes, S. faecalis, S. aureus, B. cereus and C. albicans (in vitro). DEFA4 interacts with pathogenic surface proteins and toxins such as HIV-1 gp120 and B. anthracis lethal factor. DEFA4 protects blood cells against HIV-1 infection (in vitro) and inhibits the enzymatic activity of B. anthracis lethal factor (in vitro). DEFA4 also inhibits corticotropin (ACTH)-stimulated corticosterone production (in vitro).
DEFA4 is also known as DEF4, HNP-4, HP-4, HP4.
