Premium
Assembly of different length of polyubiquitins on the catalytic cysteine of E2 enzymes without E3 ligase; a novel application of non‐reduced/reduced 2‐dimensional electrophoresis
Author(s) -
Shin Dong Yeon,
Lee Hyunju,
Park Eun Sil,
Yoo Yung Joon
Publication year - 2011
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2011.11.002
Subject(s) - ubiquitin , ubiquitin ligase , thioester , cysteine , dna ligase , chemistry , gel electrophoresis , catalysis , deubiquitinating enzyme , ubiquitin protein ligases , biochemistry , enzyme , stereochemistry , gene
In this study using non‐reduced/reduced 2‐dimensional electrophoresis (NR/R‐2DE), we clearly demonstrated that E3‐independent ubiquitination by Ube2K produced not only unanchored but also Ube2K‐linked polyubiquitins through thioester and isopeptide bonds. E3‐independent assembly of polyubiquitins on the catalytic cysteine of Ube2K strongly supports the possibility of ‘ en bloc transfer’ for polyubiquitination. From the same analyses of E3‐independent ubiquitination products by other E2s, we also found that different lengths of polyubiquitins were linked to different E2s through thioester bond; longer chains by Cdc34 like Ube2K, short chains by Ube2g2, and mono‐ubiquitin by UbcH10. Our results suggest that E2s possess the different intrinsic catalytic activities for polyubiquitination.