Key points are not available for this paper at this time.
Using the yeast two-hybrid system, we have identified a human ubiquitin-conjugating enzyme (hE2-25K) as a protein that interacts with the gene product for Huntington disease (HD) (Huntingtin). This protein has complete amino acid identity with the bovine E2-25K protein and has striking similarity to the UBC-1, -4 and -5 enzymes of Saccharomyces cerevisiae. This protein is highly expressed in brain and a slightly larger protein recognized by an anti-E2-25K polyclonal antibody is selectively expressed in brain regions affected in HD. The huntingtin-E2-25K interaction is not obviously modulated by CAG length. We also demonstrate that huntingtin is ubiquitinated. These findings have implications for the regulated catabolism of the gene product for HD.
Kalchman et al. (Thu,) studied this question.