This gene encodes an epididymal protease inhibitor, which contains both kunitz-type and WAP-type four-disulfide core (WFDC) protease inhibitor consensus sequences. Most WFDC genes are localized to chromosome 20q12-q13 in two clusters: centromeric and telomeric. This gene is a member of the WFDC gene family and belongs to the telomeric cluster. The protein can inhibit human sperm motility and exhibits antimicrobial activity against E. coli, and polymorphisms in this gene are associated with male infertility. Read-through transcription also exists between this gene and the downstream WFDC6 (WAP four-disulfide core domain 6) gene. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2014],
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Function:
similarity:Contains 1 BPTI/Kunitz inhibitor domain.,similarity:Contains 1 WAP domain.,tissue specificity:Expressed in epididymis and testis.,tissue specificity:Ubiquitously expressed, but the highest levels are found in epididymis, testis and trachea.,
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Cellular Localization:
[Isoform 1]: Secreted. Cell surface. Bound to the surface of testicular and on the head and tail of ejaculate spermatozoa.
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Tissue Expression:
In testis, expressed and secreted by Sertoli cells, appearing on the surface of testicular and ejaculate spermatozoa. Expressed in the spermatogonia and the earliest preleptotene spermatocytes. In the epididymis, is expressed and secreted by epithelial cells and covers the surface of epididymal spermatozoa and ciliated epithelial cells (at protein level). Expressed specifically in epididymis and testis. Isoform 2 is expressed only in the epididymis. Weak expression is detected in myoid cells as well as spermatogenic cells.