| Ubiquitin-conjugating enzyme 9 (Ubc9)1-3 is a component of the ubiquitin-mediated proteolytic SUMO (sentrin) pathway that targets proteins for degradation by the 26S proteasome, mediates endocytosis and directs protein subcellular localization.4,5 Ubc9 primarily mediates SUMOlation but not ubiquitinylation.6,7 An E3 ubiquitin ligase systematically transfers Ub and Ublike molecules from E2 conjugating enzymes to the targeted substrate.8 Ubc9, like other E2 family members, contains a conserved cysteine residue that is required for the thio ester formation between Ub-like proteins, and the E2 member, and it shares a conserved Ubc domain of approximately 16kD.9 More than 30 different vertebrate proteins are potential candidates for SUMOlation by Ubc9.10 Many Ubc9-interacting proteins contain a PEST sequence, a stretch of at least 12 amino acids rich in P, E, D, S, and T amino acid residues.10-13 Substrates for Ubc9 include transcription factors E12 and E47 and mitotic regulators RanBP2 and RanGAP1, indicating that Ubc9 may regulate various cellular processes including cell cycle progression and differentiation.14,15 Many Ubc9-interacting proteins have been implicated in the maintenance of vertebrate genome integrity, including the tumor suppressor protein p53,16 the promyelocytic leukemia protein (Pml),17 the poly(ADP-ribose) polymerase PARP18 and the homologous recombination proteins Rad51/52.13,16,19 Ubc9 is predominantly present in the nucleus, and at the nuclear pore complex.10, 20-22 Ubc9s distribution across the nuclear membrane, nuclear versus cytoplasmic, is important in controlling the subcellular localization of SUMOs and/or SUMOlated proteins, the assembly of Pml bodies, and the homologous recombination process mediated by Rad51.13 Applications: Suitable for use in Western Blot. Other applications not tested. Recommended Dilution: Western Blotting: 1-3ug/ml Optimal dilutions to be determined by the researcher. Storage and Stability: Store product at 4C if to be used immediately within two weeks. For long-term storage, aliquot to avoid repeated freezing and thawing and store at -20C. Aliquots are stable at -20C for 12 months after receipt. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Caution: FITC conjugates are sensitive to light. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Note: Applications are based on unconjugated antibody. |
