Protein modification by a eukaryotic-like ubiquitin-related modifier in the hyperthermophilic archaeon <i>Saccharolobus islandicus</i>.

ABSTRACT: Although homologs of the eukaryotic Urm1 (ubiquitin-related modifier-1) have been characterized in Archaea, the bona fide substrates and roles of the archaeal Urm1 remain poorly understood. Here, we report a proteomic analysis of Urm1 modification in Saccharolobus islandicus using a highly efficient method, which involves the introduction of an H81R substitution into Urm1 encoded by the strain, treatment of the strain with the proteasome inhibitor bortezomib, and affinity enrichment of urmylated peptides with an anti-K-ε-Gly-Gly antibody following peptide fractionation. Extensive protein urmylation was observed, with a total of 783 Urm1 conjugation sites, mapped to 330 proteins, identified in the cell. Among the seven lysine residues in Urm1, six were sites of modification, o

SUBMITTER: Cao J 

PROVIDER: S-EPMC12625751 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature