Protein AMPylation by Fic domain-containing proteins (Fic proteins) is an ancient and conserved post-translational modification of mostly unexplored significance. Here we characterize the Caenorhabditis elegans Fic protein FIC-1 in vitro and in vivo . FIC-1 is an AMPylase that localizes to the nuclear surface and modifies core histones H2 and H3 as well as heat shock protein 70 family members and translation elongation factors. The three-dimensional structure of FIC-1 is similar to that of its human ortholog, HYPE, with 38% sequence identity. We identify a link between FIC-1-mediated AMPylation and susceptibility to the pathogen Pseudomonas aeruginosa , establishing a connection between AMPylation and innate immunity in C . elegans . Author Summary Eukaryotic Fic domain containing proteins (Fic proteins) AMPylate target proteins at the expense of a single ATP molecule. Previous studies have established a first link between target protein AMPylation and the unfolded protein response (UPR) in the endoplasmic reticulum. Yet, the consequences of target AMPylation remain poorly understood. Here, we take a multi-faceted approach to investigate the role of the C . elegans Fic protein FIC-1 on a biochemical, structural and functional level in vitro as well as in vivo . We solve the 3-dimensional structure of FIC-1 and identify novel FIC-1 substrates belonging to the translation elongation as well as heat-shock protein families. Investigating the consequence of diminished ( fic – 1 (n5823)) or increased (FIC-1[E274G](nIs733)) AMPylation levels in vivo , we find a link between AMPylation and the innate immune response to the bacterial pathogen P . aeruginosa , describing a novel in vivo phenotype associated with Fic protein mediated target AMPylation.
【초록키워드】 innate immune response, translation, Innate immunity, susceptibility, Proteins, in vitro, Endoplasmic reticulum, Protein, pathogen, Factors, phenotype, unfolded protein response, ATP, novel, in vivo, Pseudomonas aeruginosa, Heat shock, heat shock protein, Caenorhabditis elegans, family members, elongation factors, heat-shock protein, connection, post-translational modification, biochemical, Previous studies, three-dimensional structure, domain, substrate, target proteins, previous study, target protein, ortholog, elegans, bacterial pathogen, nuclear, sequence identity, UPR, approach, consequence, identify, conserved, functional, elegan, Caenorhabditis elegan, modify, core histone, P . aeruginosa, 【제목키워드】 family, histone, Caenorhabditis elegans, Factor, elongation, Caenorhabditis, elegan,