DEFENSIN ALPHA 1 (DEFA1B) HUMAN Active Protein

Defensins are a family of antimicrobial and cytotoxic peptides thought to be involved in host defense. They are abundant in the granules of neutrophils and also found in the epithelia of mucosal surfaces such as those of the intestine, respiratory tract, urinary tract, and vagina. Members of the defensin family are highly similar in protein sequence and distinguished by a conserved cysteine motif. The protein encoded by this gene, defensin, alpha 1, is found in the microbicidal granules of neutrophils and likely plays a role in phagocyte-mediated host defense. Several alpha defensin genes are clustered on chromosome 8. This gene differs from defensin, alpha 3 by only one amino acid. This gene and the gene encoding defensin, alpha 3 are both subject to copy number variation. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2014]

defensin, alpha 1: Defensin 1 and defensin 2 have antibacterial, fungicide and antiviral activities. Has antimicrobial activity against Gram- negative and Gram-positive bacteria. Defensins are thought to kill microbes by permeabilizing their plasma membrane. Belongs to the alpha-defensin family.

Protein type: Secreted; Secreted, signal peptide

Chromosomal Location of Human Ortholog: 8p23.1

Cellular Component: extracellular matrix; extracellular space; Golgi lumen; extracellular region

Biological Process: defense response to Gram-positive bacterium; estrogen receptor signaling pathway; innate immune response in mucosa; killing of cells of another organism; antibacterial humoral response; innate immune response; immune response; chemotaxis; defense response to virus; defense response to fungus