FEATURES

FAMILY

DESCRIPTION

Also known as DEF6_HUMAN, DEFA6, DEF6. Host-defense peptide that contributes to intestinal innate immunity and mediates homeostasis at mucosal surfaces by forming higher-order oligomers that capture bacteria and prevent microbial invasion of the epithelium (PubMed:15616305, PubMed:25158166, PubMed:25354318, PubMed:28026958, PubMed:17088326). After binding to bacterial surface proteins, undergoes ordered self-assembly to form fibril-like nanonets that surround and entangle bacteria and thereby prevent bacterial invasion across the epithelial barrier (PubMed:22722251). Entangles and agglutinates Gram-negative bacteria, such as E.coli, S.typhimurium and Y.enterocolitica, and Gram-positive bacteria such as L.monocytogenes, thereby protecting the intestine against invasion by enteric bacterial pathogens (PubMed:27076903, PubMed:25158166, PubMed:22722251). Blocks adhesion of C.albicans to intestinal epithelial cells and thereby suppresses fungal invasion of epithelial cells and biofilm formation (PubMed:28026958). Under reducing conditions and in an acidic environment similar to the intestinal milieu, exhibits inhibitory activity against anaerobic bacteria such as B.adolescentis, L.acidophilus and B.breve, as well as B.longum and S.thermophilus, possibly by leading to alterations in bacterial cell envelope structures (PubMed:25354318). The disulfide-linked oxidized form exhibits negligible antimicrobial activity against Gram-negative and Gram-positive bacteria, as compared to the enteric defensin DEFA5 (PubMed:15616305, PubMed:17088326). Homodimer (PubMed:17088326, PubMed:27076903). Self-assembles into higher-order oligomers termed nanonets, fibril-like structures that entrap microbes (PubMed:22722251). Self-assembly into nanonets seems to protect against proteolytic digestion in duodenal fluid (PubMed:30808760). Interacts with Y.enterocolitica invasin and S.typhimurium fliC/flagellin; the interaction creates an anchoring site for progressive DEFA6 self-assembly into nanonets (PubMed:22722251).

EXTERNAL LINKS

DEFA6

Defensin-6

DEFA6

Molecular Synopsis