The TNFα converting enzyme (TACE) from ayu (Plecoglossus altivelis) exhibits TNFα shedding activity

摘要

TNFα converting enzyme (TACE) is responsible for converting membrane-anchored TNFα to its soluble form in mammalian. However, the function and characteristics of TACE in teleosts is unclear. In this study, we report the cloning of a cDNA sequence of the PaTACE from ayu, Plecoglossus altivelis. PaTACE encodes an 865-aa polypeptide, which is closest to the TACE gene found in pufferfish (Takifugu rubripes). PaTACE mRNA was detected in all the tissues tested, although it was considerably higher in liver, spleen, and brain tissues following infection with Listonella anguillarum. The recombinant region including the PaTACE catalytic domain was used to produce anti-PaTACE IgG. Western blot results revealed two bands for PaTACE from monocytes/macrophages. PNGase F digestion confirmed that the high molecular mass of PaTACE was caused by glycosylation. TACE activity in cell homogenates from ayu monocytes/macrophages increased following L. anguillarum infection. Moreover, PaTACE neutralization led to downregulation of TNFα expression in the supernatant of ayu monocyte/macrophages. Anti-PaTACE IgG also decreased respiratory burst in monocytes/macrophages. In conclusion, we report for the first time the TNFα-converting activity of TACE from a teleost. More investigation is needed to illustrate PaTACE-shedding activity in other immune regulators.