Heterotypic Assembly Mechanism Regulates CHIP E3 Ligase Activity

The E3 ubiquitin ligases CHIP/CHN-1 and UFD-2 team up to accelerate ubiquitin chain formation. However, it remained largely unclear how the high processivity of this E3 set is achieved. Here we studied the molecular mechanism and function of the CHN-1/UFD-2 complex in Caenorhabditis elegans. Our data show that UFD-2 binding promotes the cooperation between CHN-1 and ubiquitin-conjugating E2 enzymes by stabilizing the CHN-1 U-box dimer. The HSP-1 chaperone outcompetes UFD-2 for CHN-1 binding and promotes the auto-inhibited CHN-1 state by acting on the conserved position of the U-box domain. The interaction with UFD-2 enables CHN-1 to efficiently ubiquitinate S-Adenosylhomocysteinase (AHCY-1), an enzyme crucial for lipid metabolism. Our results define the molecular mechanism underlying the synergistic cooperation of CHN-1 and UFD-2 in substrate ubiquitylation.

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E3 ligase Rad18 promotes monoubiquitination rather than ubiquitin chain formation by E2 enzyme Rad6

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1017516108 ◽

2011 ◽

Vol 108 (14) ◽

pp. 5590-5595 ◽

Cited By ~ 76

Author(s):

R. G. Hibbert ◽

A. Huang ◽

R. Boelens ◽

T. K. Sixma

Keyword(s):

E3 Ligase ◽

Ubiquitin Chain ◽

Chain Formation

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

Biochemical Journal ◽

10.1042/bcj20210315 ◽

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.

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Faculty Opinions recommendation of E3 Ligase VHL Promotes Group 2 Innate Lymphoid Cell Maturation and Function via Glycolysis Inhibition and Induction of Interleukin-33 Receptor.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732691132.793543012 ◽

2018 ◽

Author(s):

Padraic Fallon ◽

Christian Schwartz

Keyword(s):

Lymphoid Cell ◽

E3 Ligase ◽

Cell Maturation ◽

Innate Lymphoid Cell ◽

Interleukin 33 ◽

Group 2 ◽

And Function

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Impact of obesity and SARS-CoV-2 infection: implications for host defence - a living review

Oxford Open Immunology ◽

10.1093/oxfimm/iqab001 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Felix Clemens Richter ◽

Aljawharah Alrubayyi ◽

Alicia Teijeira Crespo ◽

Sarah Hulin-Curtis ◽

Keyword(s):

Lipid Metabolism ◽

Influenza A ◽

Immune Cell ◽

Cell Metabolism ◽

Low Grade ◽

Obese Patients ◽

Healthy Weight ◽

Virus Infections ◽

Immune Alterations ◽

And Function

Abstract The role of obesity in the pathophysiology of respiratory virus infections has become particularly apparent during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, where obese patients are twice as likely to suffer from severe coronavirus disease 2019 (COVID-19) than healthy weight individuals. Obesity results in disruption of systemic lipid metabolism promoting a state of chronic low-grade inflammation. However, it remains unclear how these underlying metabolic and cellular processes promote severe SARS-CoV-2 infection. Emerging data in SARS-CoV-2 and Influenza A virus (IAV) infections show that viruses can further subvert the host’s altered lipid metabolism and exploit obesity-induced alterations in immune cell metabolism and function to promote chronic inflammation and viral propagation. In this review, we outline the systemic metabolic and immune alterations underlying obesity and discuss how these baseline alterations impact the immune response and disease pathophysiology. A better understanding of the immunometabolic landscape of obese patients may aid better therapies and future vaccine design.

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Comprehensive database of human E3 ubiquitin ligases: application to aquaporin-2 regulation

Physiological Genomics ◽

10.1152/physiolgenomics.00031.2016 ◽

2016 ◽

Vol 48 (7) ◽

pp. 502-512 ◽

Cited By ~ 31

Author(s):

Barbara Medvar ◽

Viswanathan Raghuram ◽

Trairak Pisitkun ◽

Abhijit Sarkar ◽

Mark A. Knepper

Keyword(s):

Human Genome ◽

Large Scale ◽

E3 Ligase ◽

Ubiquitin Ligases ◽

Bayes Rule ◽

E3 Ubiquitin Ligases ◽

E3 Ligases ◽

Aquaporin 2 ◽

Large Scale Data ◽

Level Data

Aquaporin-2 (AQP2) is regulated in part via vasopressin-mediated changes in protein half-life that are in turn dependent on AQP2 ubiquitination. Here we addressed the question, “What E3 ubiquitin ligase is most likely to be responsible for AQP2 ubiquitination?” using large-scale data integration based on Bayes' rule. The first step was to bioinformatically identify all E3 ligase genes coded by the human genome. The 377 E3 ubiquitin ligases identified in the human genome, consisting predominant of HECT, RING, and U-box proteins, have been used to create a publically accessible and downloadable online database ( https://hpcwebapps.cit.nih.gov/ESBL/Database/E3-ligases/ ). We also curated a second database of E3 ligase accessory proteins that included BTB domain proteins, cullins, SOCS-box proteins, and F-box proteins. Using Bayes' theorem to integrate information from multiple large-scale proteomic and transcriptomic datasets, we ranked these 377 E3 ligases with respect to their probability of interaction with AQP2. Application of Bayes' rule identified the E3 ligases most likely to interact with AQP2 as (in order of probability): NEDD4 and NEDD4L (tied for first), AMFR, STUB1, ITCH, ZFPL1. Significantly, the two E3 ligases tied for top rank have also been studied extensively in the reductionist literature as regulatory proteins in renal tubule epithelia. The concordance of conclusions from reductionist and systems-level data provides strong motivation for further studies of the roles of NEDD4 and NEDD4L in the regulation of AQP2 protein turnover.

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E3 ligase CHIP and Hsc70 regulate Kv1.5 protein expression and function in mammalian cells

Journal of Molecular and Cellular Cardiology ◽

10.1016/j.yjmcc.2015.07.018 ◽

2015 ◽

Vol 86 ◽

pp. 138-146 ◽

Cited By ~ 10

Author(s):

Peili Li ◽

Yasutaka Kurata ◽

Nani Maharani ◽

Endang Mahati ◽

Katsumi Higaki ◽

...

Keyword(s):

Protein Expression ◽

Mammalian Cells ◽

E3 Ligase ◽

And Function

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Role of Ubiquitin Ligases and the Proteasome in Oncogenesis: Novel Targets for Anticancer Therapies

Journal of Clinical Oncology ◽

10.1200/jco.2012.44.0958 ◽

2013 ◽

Vol 31 (9) ◽

pp. 1231-1238 ◽

Cited By ~ 100

Author(s):

Lindsey N. Micel ◽

John J. Tentler ◽

Peter G. Smith ◽

Gail S. Eckhardt

Keyword(s):

Cell Cycle ◽

Anticancer Agents ◽

Cell Cycle Control ◽

Ubiquitin Proteasome System ◽

Cellular Regulation ◽

Ubiquitin Chain ◽

Key Enzyme ◽

Ubiquitin Proteasome ◽

Enzyme Families ◽

And Function

The ubiquitin proteasome system (UPS) regulates the ubiquitination, and thus degradation and turnover, of many proteins vital to cellular regulation and function. The UPS comprises a sequential series of enzymatic processes using four key enzyme families: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-carrier proteins), E3 (ubiquitin-protein ligases), and E4 (ubiquitin chain assembly factors). Because the UPS is a crucial regulator of the cell cycle, and abnormal cell-cycle control can lead to oncogenesis, aberrancies within the UPS pathway can result in a malignant cellular phenotype and thus has become an attractive target for novel anticancer agents. This article will provide an overall review of the mechanics of the UPS, describe aberrancies leading to cancer, and give an overview of current drug therapies selectively targeting the UPS.

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