|Detection of Human Ubiquitin+1 by Western Blot. Western blot shows samples of Recombinant Human Ubiquitin (Catalog # 701‑UB) (2 ng) and Recombinant Human Ubiquitin+1 (Catalog # 703‑UB) (2, 1, and 0.5 ng). PVDF membrane was probed with 1 µg/mL Rabbit Anti-Human Ubiquitin+1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF703) followed by HRP-conjugated Anti-Rabbit IgG Secondary Antibody (Catalog # HAF008). A specific band for Ubiquitin+1 was detected at approximately 13 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 4.|
Ubiquitin+1 has a carboxyl terminal amino acid sequence that differs from normal Ubiquitin. The different carboxyl terminal sequence appears to result from a frameshift in the Ubiquitin mRNA. The underlying mechanisms creating the mRNA frameshift are not clearly understood. The occurrence of the frameshift that generates Ubiquitin+1 is much more prevalent in patients with Alzheimers Disease or with Down Syndrome than in control individuals who are not afflicted with the disorders. The monoclonal anti-Ubiquitin+1 (Catalog # MAB703) and rabbit polyclonal anti-Ubiquitin+1 (Catalog # AF703) antibodies were raised against the Ubiquitin+1 carboxyl terminal sequence that differs from normal Ubiquitin and are therefore non-reactive with Ubiquitin. Monoclonal anti-Ubiquitin (Catalog # MAB701) detects both Ubiquitin and Ubiquitin+1 indicating that the epitope recognized by this antibody is contained in the portion of the proteins that are identical (1, 2).