defensin beta 126
The information on this page was automatically extracted from online scientific databases.
From NCBI Gene:
Defensins are cysteine-rich cationic polypeptides that are important in the immunologic response to invading microorganisms. The antimicrobial protein encoded by this gene is secreted and is a member of the beta defensin protein family. Beta defensin genes are found in several clusters throughout the genome, with this gene mapping to a cluster at 20p13. The encoded protein is highly similar to an epididymal-specific secretory protein (ESP13.2) from cynomolgus monkey. Mutation of this gene is associated with impaired sperm function. [provided by RefSeq, Nov 2014]
Highly glycosylated atypical beta-defensin involved in several aspects of sperm function. Facilitates sperm transport in the female reproductive tract and contributes to sperm protection against immunodetection; both functions are probably implicating the negative surface charge provided by its O-linked oligosaccharides in the sperm glycocalyx. Involved in binding of sperm to oviductal epithelial cells to form a sperm reservoir until ovulation. Release from the sperm surface during capacitation and ovaluation by an elevation of oviductal fluid pH is unmasking other surface components and allows sperm to penetrate the cumulus matrix and bind to the zona pellucida of the oocyte (By similarity). In vitro has antimicrobial activity and may inhibit LPS-mediated inflammation (PubMed:19373462, PubMed:23229569).
May be involved in infertility. Homozygosity for frameshift truncating mutations are associated with reduced sperm O-linked glycan content, impaired sperm mobility and a reduced live birth rate (PubMed:21775668, PubMed:25721098). However, for one common mutation the change in sperm sialic acid levels has been challenged (PubMed:26832966).