Ubiquitin is a conserved polypeptide unit that plays an important role in the ubiquitin-proteasome pathway. Ubiquitin can be covalently linked to many cellular proteins by the ubiquitination process. This process labels the target protein as a degradation marker for 26S lysosome. Three components are involved in the target protein-ubiquitin conjugation process. Ubiquitin is first activated by forming a thiolester complex with the activation component E1. The activated ubiquitin is subsequently transfered to the ubiquitin-carrier protein E2. E2 is processed to ubiquitin ligase E3 for final delivery to the epsilon-NH2 of the target protein lysine residue (1-3). The ubiquitin-proteasome pathway has been implicated in a wide range of normal biological processes and in disease-related abnormal cases. Several examples (i.e. IkappaB, p53, cdc25a and Bcl-2) have been shown to be targets for the ubiquitination-proteosome process for regulation of cell cycle progression and differentiation, cell stress response and apoptosis (4-7). Applications: Suitable for use in Western Blot and Immunohistochemistry. Other applications not tested. Recommended Dilution: Western Blot: 1:1000 Immunohistochemistry (Paraffin): 1:750 Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4C for short-term only. For long-term storage, store at -20C. Aliquots are stable for at least 12 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
