Fig 4. Mutation of the lysine residues of Ubc9 in TTR_Ubc9 and Ubc9_TTR affects the SUMOylation patterns.

TTR fused to non-mutated (U) or the K14,153,154R mutant of Ubc9 (U^mut) located at either the N-terminus (T_U and T_U^mut) (A) or the C-terminus (U_T and U^mut_T) (B) was co-expressed with EGFP-labelled SUMO-1 (ES1), SUMO-3 (ES3) or EGFP (E) in the HEK293 cell line. Cell lysates were analysed by WB using anti-TTR antibodies (αTTR). ES conjugates and X conjugates indicate proteins modified by EGFP-labelled SUMO or endogenous modifiers, respectively. The asterisks mark truncated products of SUMOylation. The arrow indicates the band with altered mobility.