Activity: Verified in Poly-ubiquitin Chain Synthesis Assay.
Verified Applications: In vitro, recombinant Ubiquitin-protein ligase E3C accepts activated ubiquitin from E2 conjugating enzymes UBE2D1 or UBE2L3, in a reaction that also requires Ubiquitin Activating Enzyme 1 (an E1). The charged E3 is capable of producing anchored and unanchored poly-ubiquitin chains. Appropriate enzyme concentrations are specific to the application.
2 μg UBA1 run on 4-12% SDS-PAGE gel under reducing conditions, then visualized with Colloidal Coomassie Blue Stain.
Formulation: 40 mM HEPES, 100 mM NaCl, 10% Glycerol, 1 mM EDTA, 1 mM TCEP, pH 7.6
Shipping: The product is shipped with dry ice or equivalent. Upon receipt, store it immediately at the temperature recommended below.
Storage and Stability: Use a manual defrost freezer and avoid repeated freeze-thaw cycles. Aliquot and store ≤ -70°C (stable for 24 months from date of receipt).
Protein Sequence: MGWSHPQFEKGSHHHHHHGSLEVLFQGPGSMSDQEAKPSTEDLGDKKEGEYIKLKVIGQDSSEIHFKVKMTTHLKKLKESYCQRQGVPMNSLRFLFEGQRIADNHTPKELGMEEEDVIEVYQEQTGGVPFEERVKIFQRLIYADKQEVQGDGPFLDGINVTIRRNYIYEDAYDKLSPENEPDLKKRIRVHLLNAHGLDEAGIDGGGIFREFLNELLKSGFNPNQGFFKTTNEGLLYPNPAAQMLVGDSFARHYYFLGRMLGKALYENMLVELPFAGFFLSKLLGTSADVDIHHLASLDPEVYKNLLFLKSYEDDVEELGLNFTVVNNDLGEAQVVELKFGGKDIPVTSANRIAYIHLVADYRLNRQIRQHCLAFRQGLANVVSLEWLRMFDQQEIQVLISGAQVPISLEDLKSFTNYSGGYSADHPVIKVFWRVVEGFTDEEKRKLLKFVTSCSRPPLLGFKELYPAFCIHNGGSDLERLPTASTCMNLLKLPEFYDETLLRSKLLYAIECAAGFELS
Background Information and Alternate Names
Species & domain architecture
UBE3C contains an N-terminal CTA (C-terminal acidic) region that mediates proteasome docking, two central coiled coils, and a C-terminal HECT module (Cys1051 active site). The isolated HECT domain adopts an open L-shaped conformation with a flexible “acid loop” that gates E2–Ub approach.
UPS pathway role
Anchored to 26S proteasomes, UBE3C elongates or regenerates ubiquitin chains on stalled substrates, favoring Lys29/Lys48 linkages that accelerate extraction and translocation. In cancer cells, UBE3C drives β-catenin–dependent transcription and maintains stem-like traits, partly by degrading AHNAK.
Relevance to TPD & disease biology
Over-expression correlates with poor prognosis in breast, renal, lung, and brain tumors, highlighting UBE3C as a potential therapeutic target. Conversely, transient activation may bolster proteasomal clearance of toxic proteins in neurodegeneration or enhance antiviral immunity. Its strict linkage bias and proteasome residency make recombinant UBE3C a sought-after scaffold for degrader design, proteasome-tuning screens, and linkage-specific tool development.
References
You, J. and C. M. Pickart (2001) J Biol Chem 276:19871-78. PMID 11278995
Chu, B. W., et al., (2013) J Biol Chem 288:34575-87. PMID 24158444
Singh, S., and J. Sivaraman (2020) Biochem J 477:905-23. PMID 32039437
Hang, C., et al., (2021) Cancer Cell Int 21:25. PMID 33407510
Cui, B., et al., (2024) J Virol 98:e0133524. PMID 39212385
