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

Abstract 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.