High impact information on UBE2D2

• Reconstitution of p53-ubiquitinylation reactions from purified components: the role of human ubiquitin-conjugating enzyme UBC4 and E6-associated protein (E6AP) [1].
• We show that suppression of UbcH5B/C inhibits p53 ubiquitination and degradation [2].
• In MCF7 cells levels of UbcH5B/C are reduced by doxorubicin and actinomycin D [2].
• Surprisingly, with Ubc4 as the E2 enzyme, Zn(2+) ions alone are sufficient to catalyze the ubiquitination of cyclin B1 [3].
• Nedd-4 was determined to have a second nonoverlapping E2 binding site that recognizes the first 67 amino acids of UbcH5B but not the more C-terminal portion of this E2 [4].

Biological context of UBE2D2

• SCF(beta-TRCP) and phosphorylation dependent ubiquitinationof I kappa B alpha catalyzed by Ubc3 and Ubc4 [5].
• The presence of H(2)O(2) also blocked the co-immunoprecipitation of Ubc4 with APC11 and delayed the exit of cells from mitosis [6].
• Structural model of the UbcH5B/CNOT4 complex revealed by combining NMR, mutagenesis, and docking approaches [7].
• UBCx and UBC4 are active in a similar concentration range and with similar kinetics [8].
• We show that the fusion protein of EL5 with maltose binding protein (MBP) was polyubiquitinated by incubation with ubiquitin, ubiquitin-activating enzyme (E1), and the Ubc4/5 subfamily of the ubiquitin-conjugating enzyme (E2) [9].

Anatomical context of UBE2D2

• In contrast to UBC4 whose removal from a testis extract abrogates much of the conjugation activity, immmunodepletion of Rat100 from the extracts had little effect [10].
• Both DEAE unadsorbed material (fraction I) and high salt eluate (fraction II) of the reticulocyte lysate are involved cooperatively in the ubiquitination process, where the ubiquitin-conjugating enzyme UBC4 can functionally substitute for fraction I [11].

Physical interactions of UBE2D2

• To understand the basis for this interaction, we identified several basic residues of UbcH5B important for binding to CNOT4 by mutational analysis [12].

Other interactions of UBE2D2

• Furthermore, nuclear localization of N-terminal deletion mutant Nedd4 enabled us to investigate the interaction between Nedd4 and E2 enzyme (Ubc4 or UbcH7) in the cell [13].
• Concomitant charge-alteration of E49 of CNOT4 and K63 of UbcH5B restored binding and re-created a functional enzyme pair, indicative of an electrostatic interaction between these residues [12].
• Regulation of p53 by the ubiquitin-conjugating enzymes UbcH5B/C in vivo [2].
• A ubiquitin-protein ligase-like activity, partially purified from fraction II by DEAE anion-exchange chromatography, also functions in concert with UBC4 [11].

Analytical, diagnostic and therapeutic context of UBE2D2

• Molecular amplification and sequencing of genomic DNA that encodes camel polyubiquitin (PUBC1) was performed by a polymerase chain reaction (PCR) using various sets of primers [14].

References