C-terminal acidic domain of ubiquitin-conjugating enzymes: A multi-functional conserved intrinsically disordered domain in family 3 of E2 enzymes

2012 ◽  
Vol 178 (3) ◽  
pp. 245-259 ◽  
Author(s):  
Alberto Arrigoni ◽  
Barbara Grillo ◽  
Alessandro Vitriolo ◽  
Luca De Gioia ◽  
Elena Papaleo
Keyword(s):  
Intrinsically Disordered ◽  
Acidic Domain ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
Intrinsically Disordered Domain

scholarly journals OTUB1 non-catalytically stabilizes the E2 ubiquitin-conjugating enzyme UBE2E1 by preventing its autoubiquitination

2018 ◽  
Vol 293 (47) ◽  
pp. 18285-18295 ◽  
Author(s):  
Nagesh Pasupala ◽  
Marie E. Morrow ◽  
Lauren T. Que ◽  
Barbara A. Malynn ◽  
Averil Ma ◽  
...  
Keyword(s):  
Polyubiquitin Chains ◽  
Protein Ubiquitination ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
In Cells ◽  
Conjugating Enzyme

OTUB1 is a deubiquitinating enzyme that cleaves Lys-48–linked polyubiquitin chains and also regulates ubiquitin signaling through a unique, noncatalytic mechanism. OTUB1 binds to a subset of E2 ubiquitin-conjugating enzymes and inhibits their activity by trapping the E2∼ubiquitin thioester and preventing ubiquitin transfer. The same set of E2s stimulate the deubiquitinating activity of OTUB1 when the E2 is not charged with ubiquitin. Previous studies have shown that, in cells, OTUB1 binds to E2-conjugating enzymes of the UBE2D (UBCH5) and UBE2E families, as well as to UBE2N (UBC13). Cellular roles have been identified for the interaction of OTUB1 with UBE2N and members of the UBE2D family, but not for interactions with UBE2E E2 enzymes. We report here a novel role for OTUB1–E2 interactions in modulating E2 protein ubiquitination. We observe that Otub1−/− knockout mice exhibit late-stage embryonic lethality. We find that OTUB1 depletion dramatically destabilizes the E2-conjugating enzyme UBE2E1 (UBCH6) in both mouse and human OTUB1 knockout cell lines. Of note, this effect is independent of the catalytic activity of OTUB1, but depends on its ability to bind to UBE2E1. We show that OTUB1 suppresses UBE2E1 autoubiquitination in vitro and in cells, thereby preventing UBE2E1 from being targeted to the proteasome for degradation. Taken together, we provide evidence that OTUB1 rescues UBE2E1 from degradation in vivo.

scholarly journals Characterization of OTUB1 activation and inhibition by different E2 enzymes

2019 ◽  
Author(s):  
Lauren T. Que ◽  
Marie E. Morrow ◽  
Cynthia Wolberger
Keyword(s):  
Deubiquitinating Enzyme ◽  
Polyubiquitin Chains ◽  
Kinetics And Thermodynamics ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
Stimulation Of

AbstractOTUB1 is a highly expressed cysteine protease that specifically cleaves K48-linked polyubiquitin chains. This unique deubiquitinating enzyme (DUB) can bind to a subset of E2 ubiquitin conjugating enzymes, forming complexes in which the two enzymes can regulate one another’s activity. OTUB1 can non-catalytically suppress the ubiquitin conjugating activity of its E2 partners by sequestering the charged E2~Ub thioester and preventing ubiquitin transfer. The same E2 enzymes, when uncharged, can stimulate the DUB activity of OTUB1 in vitro, although the importance of OTUB1 stimulation in vivo remains unclear. In order to assess the potential balance between these activities that might occur in cells, we characterized the kinetics and thermodynamics governing the formation and activity of OTUB1:E2 complexes. We show that both stimulation of OTUB1 by E2 enzymes and noncatalytic inhibition of E2 enzymes by OTUB1 occur at physiologically relevant concentrations of both partners. Whereas E2 partners differ in their ability to stimulate OTUB1 activity, we find that this variability is not correlated with the affinity of each E2 for OTUB1. In addition to UBE2N and the UBE2D isoforms, we find that OTUB1 inhibits polyubiquitination activity of all three UBE2E enzymes, UBE2E1, UBE2E2, and UBE2E3. Interestingly, although OTUB1 also inhibits the autoubiquitination activity of UBE2E1 and UBE2E2, it is unable to suppress autoubiquitination by UBE2E3.

scholarly journals Ubiquitin-Conjugating Enzymes in Cancer

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1383
Author(s):  
Quyen Thu Bui ◽  
Jeong Hee Hong ◽  
Minseok Kwak ◽  
Ji Yeon Lee ◽  
Peter Chang-Whan Lee
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Therapeutic Strategies ◽  
Migration And Invasion ◽  
Cycle Arrest ◽  
Enzyme Cascade ◽  
Ubiquitination System ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes

The ubiquitin-mediated degradation system is responsible for controlling various tumor-promoting processes, including DNA repair, cell cycle arrest, cell proliferation, apoptosis, angiogenesis, migration and invasion, metastasis, and drug resistance. The conjugation of ubiquitin to a target protein is mediated sequentially by the E1 (activating)‒E2 (conjugating)‒E3 (ligating) enzyme cascade. Thus, E2 enzymes act as the central players in the ubiquitination system, modulating various pathophysiological processes in the tumor microenvironment. In this review, we summarize the types and functions of E2s in various types of cancer and discuss the possibility of E2s as targets of anticancer therapeutic strategies.

scholarly journals Reconstitution of human CMG helicase ubiquitylation by CUL2LRR1 and multiple E2 enzymes

2021 ◽  
Author(s):  
Thanh Thi Le ◽  
Johanna Ainsworth ◽  
Cristian Polo Rivera ◽  
Thomas Macartney ◽  
Karim Labib
Keyword(s):  
Dna Replication ◽  
Ubiquitin Ligases ◽  
Human Cells ◽  
Ubiquitin Chain ◽  
Human Proteins ◽  
Mouse Cells ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes

Cullin ubiquitin ligases drive replisome disassembly during DNA replication termination.  In worm, frog and mouse cells, CUL2LRR1 is required to ubiquitylate the MCM7 subunit of the CMG helicase.  Here we show that cullin ligases also drive CMG-MCM7 ubiquitylation in human cells, thereby making the helicase into a substrate for the p97 unfoldase.  Using purified human proteins, including a panel of E2 ubiquitin conjugating enzymes, we have reconstituted CMG helicase ubiquitylation, dependent upon neddylated CUL2LRR1.  The reaction is highly specific to CMG-MCM7 and requires the LRR1 substrate targeting subunit, since replacement of LRR1 with the alternative CUL2 adaptor VHL switches ubiquitylation from CMG-MCM7 to HIF1.  CUL2LRR1 firstly drives monoubiquitylation of CMG-MCM7 by the UBE2D class of E2 enzymes.  Subsequently, CUL2LRR1 activates UBE2R1/R2 or UBE2G1/G2 to extend a single K48-linked ubiquitin chain on CMG-MCM7.  Thereby, CUL2LRR1 converts CMG into a substrate for p97, which disassembles the ubiquitylated helicase during DNA replication termination.

scholarly journals Evidence for an Interaction between Ubiquitin-Conjugating Enzymes and the 26S Proteasome

2000 ◽  
Vol 20 (13) ◽  
pp. 4691-4698 ◽  
Author(s):  
Prasad Tongaonkar ◽  
Li Chen ◽  
David Lambertson ◽  
Bom Ko ◽  
Kiran Madura
Keyword(s):  
Heat Stress ◽  
Stress Tolerance ◽  
Substrate Recognition ◽  
26S Proteasome ◽  
Yeast Cells ◽  
E2 Protein ◽  
Conjugating Enzymes ◽  
E2 Enzymes ◽  
Ubiquitin Conjugating Enzymes

ABSTRACT The targeting of proteolytic substrates is accomplished by a family of ubiquitin-conjugating (E2) enzymes and a diverse set of substrate recognition (E3) factors. The ligation of a multiubiquitin chain to a substrate can promote its degradation by the proteasome. However, the mechanism that facilitates the translocation of a substrate to the proteasome in vivo is poorly understood. We have discovered that E2 proteins, including Ubc1, Ubc2, Ubc4, and Ubc5, can interact with the 26S proteasome. Significantly, the interaction between Ubc4 and the proteasome is strongly induced by heat stress, consistent with the requirement for this E2 for efficient stress tolerance. A catalytically inactive derivative of Ubc4 (Ubc4C86A), which causes toxicity in yeast cells, can also bind the proteasome. Purified proteasomes can ligate ubiquitin to a test substrate without the addition of exogenous E2 protein, suggesting that the ubiquitylation of some proteolytic substrates might be directly coupled to degradation by the proteasome.

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