Bovine NK-lysin: Copy number variation and functional diversification.
Proc Natl Acad Sci U S A
; 112(52): E7223-9, 2015 Dec 29.
Article
in En
| MEDLINE
| ID: mdl-26668394
ABSTRACT
NK-lysin is an antimicrobial peptide and effector protein in the host innate immune system. It is coded by a single gene in humans and most other mammalian species. In this study, we provide evidence for the existence of four NK-lysin genes in a repetitive region on cattle chromosome 11. The NK2A, NK2B, and NK2C genes are tandemly arrayed as three copies in â¼30-35-kb segments, located 41.8 kb upstream of NK1. All four genes are functional, albeit with differential tissue expression. NK1, NK2A, and NK2B exhibited the highest expression in intestine Peyer's patch, whereas NK2C was expressed almost exclusively in lung. The four peptide products were synthesized ex vivo, and their antimicrobial effects against both Gram-positive and Gram-negative bacteria were confirmed with a bacteria-killing assay. Transmission electron microcopy indicated that bovine NK-lysins exhibited their antimicrobial activities by lytic action in the cell membranes. In summary, the single NK-lysin gene in other mammals has expanded to a four-member gene family by tandem duplications in cattle; all four genes are transcribed, and the synthetic peptides corresponding to the core regions are biologically active and likely contribute to innate immunity in ruminants.
Key words
Full text:
1
Database:
MEDLINE
Main subject:
Proteolipids
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Cattle
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Multigene Family
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Gene Dosage
Limits:
Animals
Language:
En
Journal:
Proc Natl Acad Sci U S A
Year:
2015
Type:
Article