Alternative titles; symbols
HGNC Approved Gene Symbol: DEFB121
Cytogenetic location: 20q11.21 Genomic coordinates (GRCh38): 20:31,404,845-31,418,522 (from NCBI)
Beta-defensins are a family of typically cationic antimicrobial peptides that share a signature motif consisting of 6 conserved cysteines. DEFB121 is part of a cluster of beta-defensins on chromosome 20q11.1 that are expressed in the male reproductive tract (Radhakrishnan et al., 2005).
By genomic sequence analysis using multiple computational tools, Schutte et al. (2002) identified human DEFB121. The predicted protein contains the 6-cysteine domain characteristic of beta-defensins.
Using RT-PCR and EST database analysis, Radhakrishnan et al. (2005) cloned human and macaque DEFB121. The predicted human DEFB121 protein has 76 amino acids and contains the conserved 6-cysteine signature motif of beta-defensins. RT-PCR of human tissues revealed abundant DEFB121 expression in the male reproductive tract only. DEFB121 expression was abundant in proximal epididymis (caput and corpus) and low in distal epididymis and testis.
Radhakrishnan et al. (2005) determined that, like most beta-defensin genes, DEFB121 contains 2 exons.
By genomic sequence analysis, Schutte et al. (2002) mapped the DEFB121 gene within a beta-defensin gene cluster on chromosome 20q11.1. The syntenic mouse cluster is located on chromosome 2.
Evolutionary analyses by Radhakrishnan et al. (2005) suggested that the beta-defensin gene cluster on chromosome 20q11.1, which includes DEFB121, originated by a series of duplication events and by positive selection.
Schutte et al. (2002) noted that mouse and human beta-defensin genes are designated using the stem roots 'Defb' and 'DEFB,' respectively. Mouse genes are numbered beginning with 1, whereas human genes are numbered beginning with 101. In cases where orthologous genes are confirmed, the lower gene number is used. For example, mouse beta-defensin-1 (Defb1) and human beta-defensin-1 (DEFB101) are confirmed orthologs and are therefore named Defb1 and DEFB1 (602056), respectively.
Radhakrishnan, Y., Hamil, K. G., Yenugu, S., Young, S. L., French, F. S., Hall, S. H. Identification, characterization, and evolution of a primate beta-defensin gene cluster. Genes Immun. 6: 203-210, 2005. [PubMed: 15772680] [Full Text: https://doi.org/10.1038/sj.gene.6364184]
Schutte, B. C., Mitros, J. P., Bartlett, J. A., Walters, J. D., Jia, H. P., Welsh, M. J., Casavant, T. L., McCray, P. B., Jr. Discovery of five conserved beta-defensin gene clusters using a computational search strategy. Proc. Nat. Acad. Sci. 99: 2129-2133, 2002. Note: Erratum: Proc. Nat. Acad. Sci. 99: 14611 only, 2002. [PubMed: 11854508] [Full Text: https://doi.org/10.1073/pnas.042692699]