For decades, ubiquitin has been considered almost exclusively as a protein tag. Its C-terminal Gly-Gly motif forms isopeptide (or occasionally thio-/oxy-ester) bonds with Lys, Cys, Ser or Thr residues, marking proteins for degradation, trafficking or regulation. While a handful of reports have suggested that ubiquitin can also be attached to sugars, lipids, nucleic acids or…
E-STUB: A Precision Tool for Mapping E3 Ligase Substrates In march 2025, colleagues from Dana Faber and The Broad Institute published in ๐๐ข๐ต๐ถ๐ณ๐ฆ ๐๐ฉ๐ฆ๐ฎ๐ช๐ค๐ข๐ญ ๐๐ช๐ฐ๐ญ๐ฐ๐จ๐บ: “๐๐ฃ๐ช๐ฒ๐ถ๐ช๐ต๐ช๐ฏ-๐ด๐ฑ๐ฆ๐ค๐ช๐ง๐ช๐ค ๐ฑ๐ณ๐ฐ๐น๐ช๐ฎ๐ช๐ต๐บ ๐ญ๐ข๐ฃ๐ฆ๐ญ๐ช๐ฏ๐จ ๐ง๐ฐ๐ณ ๐ต๐ฉ๐ฆ ๐ช๐ฅ๐ฆ๐ฏ๐ต๐ช๐ง๐ช๐ค๐ข๐ต๐ช๐ฐ๐ฏ ๐ฐ๐ง ๐3 ๐ญ๐ช๐จ๐ข๐ด๐ฆ ๐ด๐ถ๐ฃ๐ด๐ต๐ณ๐ข๐ต๐ฆ๐ด” How it worksE-STUB (E3-Substrate Tagging by Ubiquitin Biotinylation) combines the principles of proximity labeling with the functional specificity of ubiquitin…