scholarly journals Crystal Structure of a Fragment of Mouse Ubiquitin-activating Enzyme

2005 ◽  
Vol 280 (23) ◽  
pp. 22006-22011 ◽  
Author(s):  
Roman H. Szczepanowski ◽  
Renata Filipek ◽  
Matthias Bochtler
Keyword(s):  
Crystal Structure ◽  
Sequence Similarity ◽  
Adenylation Domain ◽  
Protein Ubiquitination ◽  
Catalytic Cysteine ◽  
Ubiquitin Ligase E3 ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
Neuronal Precursor Cell ◽  
Ubiquitin Conjugating Enzymes

Protein ubiquitination requires the sequential activity of three enzymes: a ubiquitin-activating enzyme (E1), a ubiquitin-conjugating enzyme (E2), and a ubiquitin-ligase (E3). The ubiquitin-transfer machinery is hierarchically organized; for every ubiquitin-activating enzyme, there are several ubiquitin-conjugating enzymes, and most ubiquitin-conjugating enzymes can in turn interact with multiple ubiquitin ligases. Despite the central role of ubiquitin-activating enzyme in this cascade, a crystal structure of a ubiquitin-activating enzyme is not available. The enzyme is thought to consist of an adenylation domain, a catalytic cysteine domain, a four-helix bundle, and possibly, a ubiquitin-like domain. Its adenylation domain can be modeled because it is clearly homologous to the structurally known adenylation domains of the activating enzymes for the small ubiquitin-like modifier (SUMO) and for the protein encoded by the neuronal precursor cell-expressed, developmentally down-regulated gene 8 (NEDD8). Low sequence similarity and vastly different domain lengths make modeling difficult for the catalytic cysteine domain that results from the juxtaposition of two catalytic cysteine half-domains. Here, we present a biochemical and crystallographic characterization of the two half-domains and the crystal structure of the larger, second catalytic cysteine half-domain of mouse ubiquitin-activating enzyme. We show that the domain is organized around a conserved folding motif that is also present in the NEDD8- and SUMO-activating enzymes, and we propose a tentative model for full-length ubiquitin-activating enzyme.

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.

Identification and expression analysis of E2 ubiquitin-conjugating enzymes in cucumber

2021 ◽  
Author(s):  
Wei Lai ◽  
Zhaoyang Hu ◽  
Chuxia Zhu ◽  
Yingui Yang ◽  
Shiqiang Liu ◽  
...  
Keyword(s):  
Gene Family ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Biological Processes ◽  
Protein Ubiquitination ◽  
Genome Wide ◽  
Conjugating Enzymes ◽  
Gene Structures ◽  
Ubiquitin Conjugating Enzymes ◽  
Genome Wide Survey

Protein ubiquitination is one of the most common modifications that can degrade or modify proteins in eukaryotic cells. The E2 ubiquitin-conjugating enzymes (UBCs) are involved in multiple biological processes of eukaryotes and their response to adverse stresses. Genome-wide survey of the UBC gene family has been performed in many plant species but not in cucumber (Cucumis sativus). In this study, a total of 38 UBC family genes (designated as CsUBC1–CsUBC38) were identified in cucumber. The phylogenetic analysis of UBC proteins from cucumber, Arabidopsis and maize indicated that these proteins could be divided into 15 groups. Most of the phylogenetically related CsUBC members had similar conserved motif patterns and gene structures. The CsUBC genes were unevenly distributed on seven chromosomes, and gene duplication analysis indicated that segmental duplication has played a significant role in the expansion of the cucumber UBC gene family. Promoter analysis of these genes resulted in the identification of many hormone-, stress- and development-related cis-elements. The CsUBC genes exhibited differential expression patterns in different tissues and developmental stages of fruit ripening. In addition, a total of 14 CsUBC genes were differentially expressed upon downy mildew (DM) infection compared with the control. Our results lay the foundation for further clarification of the roles of the CsUBC genes in the future.

scholarly journals Two Ubiquitin-Conjugating Enzymes, UbcP1/Ubc4 and UbcP4/Ubc11, Have Distinct Functions for Ubiquitination of Mitotic Cyclin

2003 ◽  
Vol 23 (10) ◽  
pp. 3497-3505 ◽  
Author(s):  
Hiroaki Seino ◽  
Tsutomu Kishi ◽  
Hideo Nishitani ◽  
Fumiaki Yamao
Keyword(s):  
Fission Yeast ◽  
Ubiquitin Proteasome System ◽  
High Expression ◽  
Mitotic Cyclin ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
Mutant Cells ◽  
Conjugating Enzyme

ABSTRACT Cell cycle events are regulated by sequential activation and inactivation of Cdk kinases. Mitotic exit is accomplished by the inactivation of mitotic Cdk kinase, which is mainly achieved by degradation of cyclins. The ubiquitin-proteasome system is involved in this process, requiring APC/C (anaphase-promoting complex/cyclosome) as a ubiquitin ligase. In Xenopus and clam oocytes, the ubiquitin-conjugating enzymes that function with APC/C have been identified as two proteins, UBC4 and UBCx/E2-C. Previously we reported that the fission yeast ubiquitin-conjugating enzyme UbcP4/Ubc11, a homologue of UBCx/E2-C, is required for mitotic transition. Here we show that the other fission yeast ubiquitin-conjugating enzyme, UbcP1/Ubc4, which is homologous to UBC4, is also required for mitotic transition in the same manner as UbcP4/Ubc11. Both ubiquitin-conjugating enzymes are essential for cell division and directly required for the degradation of mitotic cyclin Cdc13. They function nonredundantly in the ubiquitination of CDC13 because a defect in ubcP1/ubc4 + cannot be suppressed by high expression of UbcP4/Ubc11 and a defect in ubcP4/ubc11 + cannot be suppressed by high expression of UbcP1/Ubc4. In vivo analysis of the ubiquitinated state of Cdc13 shows that the ubiquitin chains on Cdc13 were short in ubcP1/ubc4 mutant cells while ubiquitinated Cdc13 was totally reduced in ubcP4/ubc11 mutant cells. Taken together, these results indicate that the two ubiquitin-conjugating enzymes play distinct and essential roles in the degradation of mitotic cyclin Cdc13, with the UbcP4/Ubc11-pathway initiating ubiquitination of Cdc13 and the UbcP1/Ubc4-pathway elongating the short ubiquitin chains on Cdc13.

Hug and hold tight: Dimerization controls the turnover of the ubiquitin-conjugating enzyme UBE2S

2020 ◽  
Vol 13 (654) ◽  
pp. eabd9892
Author(s):  
Anja Bremm
Keyword(s):  
Half Life ◽  
Anaphase Promoting Complex ◽  
Ubiquitin Chain ◽  
Precise Control ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
Chain Synthesis ◽  
Ubiquitin Conjugating Enzymes ◽  
Conjugating Enzyme

Precise control of the activity and abundance of ubiquitin-conjugating enzymes (E2s) ensures fidelity in ubiquitin chain synthesis. In this issue of Science Signaling, Liess et al. demonstrate that the human anaphase-promoting complex (APC/C)–associated E2 UBE2S adopts an autoinhibited dimeric state that increases the half-life of UBE2S by preventing its autoubiquitination-driven turnover.

scholarly journals The Fission Yeast Ubiquitin-Conjugating Enzymes UbcP3, Ubc15, and Rhp6 Affect Transcriptional Silencing of the Mating-Type Region

2002 ◽  
Vol 1 (4) ◽  
pp. 613-625 ◽  
Author(s):  
Inga Sig Nielsen ◽  
Olaf Nielsen ◽  
Johanne M. Murray ◽  
Geneviève Thon
Keyword(s):  
Fission Yeast ◽  
Rna Polymerase Ii ◽  
Mating Type ◽  
26S Proteasome ◽  
Obvious Effect ◽  
Type Region ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
Active Site Mutants

ABSTRACT Genes transcribed by RNA polymerase II are silenced when introduced near the mat2 or mat3 mating-type loci of the fission yeast Schizosaccharomyces pombe. Silencing is mediated by a number of gene products and cis-acting elements. We report here the finding of novel trans-acting factors identified in a screen for high-copy-number disruptors of silencing. Expression of cDNAs encoding the putative E2 ubiquitin-conjugating enzymes UbcP3, Ubc15 (ubiquitin-conjugating enzyme), or Rhp6 (Rad homolog pombe) from the strong nmt1 promoter derepressed the silent mating-type loci mat2 and mat3 and reporter genes inserted nearby. Deletion of rhp6 slightly derepressed an ade6 reporter gene placed in the mating-type region, whereas disruption of ubcP3 or ubc15 had no obvious effect on silencing. Rhp18 is the S. pombe homolog of Saccharomyces cerevisiae Rad18p, a DNA-binding protein that physically interacts with Rad6p. Rhp18 was not required for the derepression observed when UbcP3, Ubc15, or Rhp6 was overproduced. Overexpressing Rhp6 active-site mutants showed that the ubiquitin-conjugating activity of Rhp6 is essential for disruption of silencing. However, high dosage of UbcP3, Ubc15, or Rhp6 was not suppressed by a mutation in the 26S proteasome, suggesting that loss of silencing is not due to an increased degradation of silencing factors but rather to the posttranslational modification of proteins by ubiquitination. We discuss the implications of these results for the possible modes of action of UbcP3, Ubc15, and Rhp6.

scholarly journals UBE2E Ubiquitin-conjugating Enzymes and Ubiquitin Isopeptidase Y Regulate TDP-43 Protein Ubiquitination

2014 ◽  
Vol 289 (27) ◽  
pp. 19164-19179 ◽  
Author(s):  
Friederike Hans ◽  
Fabienne C. Fiesel ◽  
Jennifer C. Strong ◽  
Sandra Jäckel ◽  
Tobias M. Rasse ◽  
...  
Keyword(s):  
Protein Ubiquitination ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes

scholarly journals A novel rat homolog of the Saccharomyces cerevisiae ubiquitin-conjugating enzymes UBC4 and UBC5 with distinct biochemical features is induced during spermatogenesis.

1996 ◽  
Vol 16 (8) ◽  
pp. 4064-4072 ◽  
Author(s):  
S S Wing ◽  
N Bédard ◽  
C Morales ◽  
P Hingamp ◽  
J Trasler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Similarity ◽  
Amino Acid Identity ◽  
Cellular Function ◽  
Rat Tissues ◽  
Regulation Of Expression ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes ◽  
First Time

The Saccharomyces cerevisiae ubiquitin-conjugating enzymes (E2s) UBC4 and UBC5 are essential for degradation of short-lived and abnormal proteins. We previously identified rat cDNAs encoding two E2s with strong sequence similarity to UBC4 and UBC5. These E2 isoforms are widely expressed in rat tissues, consistent with a fundamental cellular function for these E2s. We now report a new isoform, 8A, which despite having >91% amino acid identity with the other isoforms, shows several novel features. Expression of the 8A isoform appears restricted to the testis, is absent in early life, but is induced during puberty. Hypophysectomy reduced expression of the 8A isoform. In situ hybridization studies indicated that 8A mRNA is expressed mainly in round spermatids. Immunoblot analyses showed that 8A protein is found not only in subfractions of germ cells enriched in round spermatids but also in subfractions containing residual bodies extruded from more mature elongated spermatids, indicating that the protein possesses a longer half-life than the mRNA. Unlike all previously identified mammalian and plant homologs of S. cerevisiae UBC4, which possess a basic pI, the 8A isoform is unique in possessing an acidic pI. The small differences in sequence between the 8A isoform and other rat isoforms conferred differences in biochemical function. The 8A isoform was less effective than an isoform with a basic pI or ineffective in conjugating ubiquitin to certain fractions of testis proteins. Thus, although multiple isoforms of a specific E2 may exist to ensure performance of a critical cellular function, our data demonstrate, for the first time, that multiple genes also permit highly specialized regulation of expression of specific isoforms and that subtle differences in E2 primary structure can dictate conjugation of ubiquitin to different subsets of cellular proteins.

Tertiary structures of class I ubiquitin-conjugating enzymes are highly conserved: Crystal structure of yeast Ubc4

Biochemistry ◽  
1993 ◽  
Vol 32 (50) ◽  
pp. 13809-13817 ◽  
Author(s):  
William J. Cook ◽  
Leigh C. Jeffrey ◽  
Yuping Xu ◽  
Vincent Chau
Keyword(s):  
Crystal Structure ◽  
Class I ◽  
Tertiary Structures ◽  
Conjugating Enzymes ◽  
Ubiquitin Conjugating Enzymes

scholarly journals A Giant Ubiquitin-conjugating Enzyme Related to IAP Apoptosis Inhibitors

1998 ◽  
Vol 141 (6) ◽  
pp. 1415-1422 ◽  
Author(s):  
Hans-Peter Hauser ◽  
Michael Bardroff ◽  
George Pyrowolakis ◽  
Stefan Jentsch
Keyword(s):  
Covalent Attachment ◽  
Protein Protein Interaction ◽  
Small Proteins ◽  
The Family ◽  
Golgi Compartment ◽  
Ubiquitin Conjugating Enzyme ◽  
Conjugating Enzymes ◽  
And Function ◽  
Ubiquitin Conjugating Enzymes ◽  
Conjugating Enzyme

Ubiquitin-conjugating enzymes (UBC) catalyze the covalent attachment of ubiquitin to target proteins and are distinguished by the presence of a UBC domain required for catalysis. Previously identified members of this enzyme family are small proteins and function primarily in selective proteolysis pathways. Here we describe BRUCE (BIR repeat containing ubiquitin-conjugating enzyme), a giant (528-kD) ubiquitin-conjugating enzyme from mice. BRUCE is membrane associated and localizes to the Golgi compartment and the vesicular system. Remarkably, in addition to being an active ubiquitin-conjugating enzyme, BRUCE bears a baculovirus inhibitor of apoptosis repeat (BIR) motif, which to this date has been exclusively found in apoptosis inhibitors of the IAP-related protein family. The BIR motifs of IAP proteins are indispensable for their anti–cell death activity and are thought to function through protein–protein interaction. This suggests that BRUCE may combine properties of IAP-like proteins and ubiquitin-conjugating enzymes and indicates that the family of IAP-like proteins is structurally and functionally more diverse than previously expected.

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