scholarly journals A GID E3 ligase assembly ubiquitinates an Rsp5 E3 adaptor and regulates plasma membrane transporters

2021 ◽  
Author(s):  
Christine R. Langlois ◽  
Viola Beier ◽  
Ozge Karayel ◽  
Jakub Chrustowicz ◽  
Dawafuti Sherpa ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Plasma Membrane ◽  
E3 Ligase ◽  
Membrane Transporters ◽  
Specific Substrate ◽  
Receptor Subunit ◽  
Alternative Substrate ◽  
E3 Ligases ◽  
Interaction Partners ◽  
Regulatory Functions

AbstractCells rapidly remodel their proteomes to align their cellular metabolism to environmental conditions. Ubiquitin E3 ligases enable this response, by facilitating rapid and reversible changes to protein stability, localization, or interaction partners. In S. cerevisiae, the GID E3 ligase regulates the switch from gluconeogenic to glycolytic conditions through induction and incorporation of the substrate receptor subunit Gid4, which promotes the degradation of gluconeogenic enzymes. Here, we show an alternative substrate receptor, Gid10, which is induced in response to changes in temperature, osmolarity and nutrient availability, and regulates the ART-Rsp5 pathway. Art2 levels are elevated upon GID10 deletion, a crystal structure shows the basis for Gid10-Art2 interactions, and Gid10 directs a GID E3 ligase complex to ubiquitinate Art2. We also find that the GID E3 ligase affects the flux of plasma membrane nutrient transporters during heat stress. The data reveal GID as a system of E3 ligases with metabolic regulatory functions outside of glycolysis and gluconeogenesis, controlled by distinct stress-specific substrate receptors.

scholarly journals E3 ligase Nedd4l promotes antiviral innate immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng Gao ◽  
Xianwei Ma ◽  
Ming Yuan ◽  
Yulan Yi ◽  
Guoke Liu ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Type I Interferon ◽  
Zinc Fingers ◽  
E3 Ligase ◽  
Type I ◽  
E3 Ligases ◽  
Protein Posttranslational Modifications ◽  
Antiviral Innate Immunity

AbstractUbiquitination is one of the most prevalent protein posttranslational modifications. Here, we show that E3 ligase Nedd4l positively regulates antiviral immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3. Deficiency of Nedd4l significantly impairs type I interferon and proinflammatory cytokine production induced by virus infection both in vitro and in vivo. Nedd4l deficiency inhibits virus-induced ubiquitination of TRAF3, the binding between TRAF3 and TBK1, and subsequent phosphorylation of TBK1 and IRF3. Nedd4l directly interacts with TRAF3 and catalyzes K29-linked ubiquitination of Cys56 and Cys124, two cysteines that constitute zinc fingers, resulting in enhanced association between TRAF3 and E3 ligases, cIAP1/2 and HECTD3, and also increased K48/K63-linked ubiquitination of TRAF3. Mutation of Cys56 and Cys124 diminishes Nedd4l-catalyzed K29-linked ubiquitination, but enhances association between TRAF3 and the E3 ligases, supporting Nedd4l promotes type I interferon production in response to virus by catalyzing ubiquitination of the cysteines in TRAF3.

scholarly journals Pirh2, an E3 ligase, regulates the AIP4–p73 regulatory pathway by modulating AIP4 expression and ubiquitination

2021 ◽  
Author(s):  
Rami Abou Zeinab ◽  
H Helena Wu ◽  
Yasser Abuetabh ◽  
Sarah Leng ◽  
Consolato Sergi ◽  
...  
Keyword(s):  
Regulatory Protein ◽  
Ectopic Expression ◽  
E3 Ligase ◽  
Regulatory Pathway ◽  
Hect Domain ◽  
E3 Ligases ◽  
Multiple Substrates ◽  
Protein Levels ◽  
Cycle Arrest ◽  
Negative Regulatory Pathway

Abstract Pirh2 is an E3 ligase belonging to the RING-H2 family and shown to bind, ubiquitinate and downregulate p73 tumor suppressor function without altering p73 protein levels. AIP4, an E3 ligase belonging to the HECT domain family, has been reported to be a negative regulatory protein that promotes p73 ubiquitination and degradation. Herein, we found that Pirh2 is a key regulator of AIP4 that inhibits p73 function. Pirh2 physically interacts with AIP4 and significantly downregulates AIP4 expression. This downregulation is shown to involve the ubiquitination of AIP4 by Pirh2. Importantly, we demonstrated that the ectopic expression of Pirh2 inhibits the AIP4–p73 negative regulatory pathway, which was restored when depleting endogenous Pirh2 utilizing Pirh2-siRNAs. We further observed that Pirh2 decreases AIP4-mediated p73 ubiquitination. At the translational level and specifically regarding p73 cell cycle arrest function, Pirh2 still ensures the arrest of p73-mediated G1 despite AIP4 expression. Our study reveals a novel link between two E3 ligases previously thought to be unrelated in regulating the same effector substrate, p73. These findings open a gateway to explain how E3 ligases differentiate between regulating multiple substrates that may belong to the same family of proteins, as it is the case for the p53 and p73 proteins.

scholarly journals A fine balance between Prpf19 and Exoc7 in achieving degradation of aggregated protein and suppression of cell death in spinocerebellar ataxia type 3

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhefan Stephen Chen ◽  
Xiaoying Huang ◽  
Kevin Talbot ◽  
Ho Yin Edwin Chan
Keyword(s):  
Spinocerebellar Ataxia ◽  
E3 Ligase ◽  
Spinocerebellar Ataxia Type ◽  
Disease Genes ◽  
Spinocerebellar Ataxia Type 3 ◽  
E3 Ligases ◽  
Protein Ubiquitination ◽  
Polyq Protein ◽  
Polyq Diseases ◽  
Type 3

AbstractPolyglutamine (polyQ) diseases comprise Huntington’s disease and several subtypes of spinocerebellar ataxia, including spinocerebellar ataxia type 3 (SCA3). The genomic expansion of coding CAG trinucleotide sequence in disease genes leads to the production and accumulation of misfolded polyQ domain-containing disease proteins, which cause cellular dysfunction and neuronal death. As one of the principal cellular protein clearance pathways, the activity of the ubiquitin–proteasome system (UPS) is tightly regulated to ensure efficient clearance of damaged and toxic proteins. Emerging evidence demonstrates that UPS plays a crucial role in the pathogenesis of polyQ diseases. Ubiquitin (Ub) E3 ligases catalyze the transfer of a Ub tag to label proteins destined for proteasomal clearance. In this study, we identified an E3 ligase, pre-mRNA processing factor 19 (Prpf19/prp19), that modulates expanded ataxin-3 (ATXN3-polyQ), disease protein of SCA3, induced neurodegeneration in both mammalian and Drosophila disease models. We further showed that Prpf19/prp19 promotes poly-ubiquitination and degradation of mutant ATXN3-polyQ protein. Our data further demonstrated the nuclear localization of Prpf19/prp19 is essential for eliciting its modulatory function towards toxic ATXN3-polyQ protein. Intriguingly, we found that exocyst complex component 7 (Exoc7/exo70), a Prpf19/prp19 interacting partner, modulates expanded ATXN3-polyQ protein levels and toxicity in an opposite manner to Prpf19/prp19. Our data suggest that Exoc7/exo70 exerts its ATXN3-polyQ-modifying effect through regulating the E3 ligase function of Prpf19/prp19. In summary, this study allows us to better define the mechanistic role of Exoc7/exo70-regulated Prpf19/prp19-associated protein ubiquitination pathway in SCA3 pathogenesis.

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

2016 ◽  
Vol 48 (7) ◽  
pp. 502-512 ◽  
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.

scholarly journals KCTD proteins as Cullin3 E3 Ligase adapters

2014 ◽  
Vol 70 (a1) ◽  
pp. C305-C305
Author(s):  
Alan Ji ◽  
Gilbert Privé
Keyword(s):  
Crystal Structure ◽  
Structural Characterization ◽  
Dissociation Constants ◽  
E3 Ligase ◽  
Terminal Region ◽  
Btb Domain ◽  
Substrate Protein ◽  
Ubiquitin E3 Ligase ◽  
Ubiquitin Moiety

Cullin3 (Cul3) is an ubiquitin E3 ligase responsible for catalyzing the transfer of an ubiquitin moiety from an E2 enzyme to a target substrate protein. The C-terminal region of Cul3 binds RBX1/E2-ubiquitin, while, the N-terminal region interacts with various BTB domain proteins which serve as substrate adaptors. Previously, our group determined the crystal structures of the homodimeric BTB proteins SPOP and KLHL3 in complex with the N-terminal domain of Cul3, revealing the determinants responsible for the BTB/Cul3 interaction [1, 2]. A second class of BTB-domain containing proteins, the KCTD proteins, are also Cul3 substrate adaptors but these do not share many of the previously determined features for Cul3 binding. Furthermore, KCTD proteins form homotetramers and homopentamers via BTB oligomerization rather than the previously described homodimers. Despite these differences, many KCTD proteins interact with Cul3 with dissociation constants of approximately 50 nM. While the target substrates for many of the KCTD/Cul3 E3 ligase complexes are unknown, recent studies have implicated the GABAβ2 receptor as an interactor of KCTD 8, 12, 12b and 16. Here, we report the pentameric crystal structure of the KCTD9 BTB domain and our progress on the structural characterization of Cul3/KCTD/substrate complexes.

scholarly journals Inhibition of HECT E3 ligases as potential therapy for COVID-19

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Giuseppe Novelli ◽  
◽  
Jing Liu ◽  
Michela Biancolella ◽  
Tonino Alonzi ◽  
...  
Keyword(s):  
World Wide ◽  
Therapeutic Strategy ◽  
Rna Viruses ◽  
Family Members ◽  
E3 Ligase ◽  
Direct Interaction ◽  
Spike Protein ◽  
E3 Ligases ◽  
Antiviral Effects ◽  
Novel Biomarkers

AbstractSARS-CoV-2 is responsible for the ongoing world-wide pandemic which has already taken more than two million lives. Effective treatments are urgently needed. The enzymatic activity of the HECT-E3 ligase family members has been implicated in the cell egression phase of deadly RNA viruses such as Ebola through direct interaction of its VP40 Protein. Here we report that HECT-E3 ligase family members such as NEDD4 and WWP1 interact with and ubiquitylate the SARS-CoV-2 Spike protein. Furthermore, we find that HECT family members are overexpressed in primary samples derived from COVID-19 infected patients and COVID-19 mouse models. Importantly, rare germline activating variants in the NEDD4 and WWP1 genes are associated with severe COVID-19 cases. Critically, I3C, a natural NEDD4 and WWP1 inhibitor from Brassicaceae, displays potent antiviral effects and inhibits viral egression. In conclusion, we identify the HECT family members of E3 ligases as likely novel biomarkers for COVID-19, as well as new potential targets of therapeutic strategy easily testable in clinical trials in view of the established well-tolerated nature of the Brassicaceae natural compounds.

Calcium- and potassium-permeable plasma membrane transporters are activated by copper inArabidopsisroot tips: linking copper transport with cytosolic hydroxyl radical production

2012 ◽  
Vol 36 (4) ◽  
pp. 844-855 ◽  
Author(s):  
ANA RODRIGO-MORENO ◽  
NURIA ANDRÉS-COLÁS ◽  
CHARLOTTE POSCHENRIEDER ◽  
BENET GUNSÉ ◽  
LOLA PEÑARRUBIA ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Hydroxyl Radical ◽  
Copper Transport ◽  
Membrane Transporters ◽  
Radical Production

Identification of ferrichrome- and ferrioxamine B-mediated iron uptake by Aspergillus fumigatus

2016 ◽  
Vol 473 (9) ◽  
pp. 1203-1213 ◽  
Author(s):  
Yong-Sung Park ◽  
Ju-Yeon Kim ◽  
Cheol-Won Yun
Keyword(s):  
Gene Expression ◽  
Plasma Membrane ◽  
Aspergillus Fumigatus ◽  
Virulence Factors ◽  
Membrane Transporters ◽  
Yeast Cells ◽  
Double Deletion ◽  
Ferrioxamine B ◽  
Uptake Activity ◽  
Opportunistic Fungal Pathogen

Aspergillus fumigatus is an opportunistic fungal pathogen for immunocompromised patients, and genes involved in siderophore metabolism have been identified as virulence factors. Recently, we identified the membrane transporters sit1 and sit2, which are putative virulence factors of A. fumigatus; sit1 and sit2 are homologous to yeast Sit1, and sit1 and sit2 gene expression was up-regulated after iron depletion. When expressed heterologously in Saccharomyces cerevisiae, sit1 and sit2 were localized to the plasma membrane; sit1 efficiently complemented ferrichrome (FC) and ferrioxamine B (FOB) uptake in yeast cells, whereas sit2 complemented only FC uptake. Deletion of sit1 resulted in a decrease in FOB and FC uptake, and deletion of sit2 resulted in a decrease in FC uptake in A. fumigatus. It is of interest that a sit1 and sit2 double-deletion mutant resulted in a synergistic decrease in FC uptake activity. Both sit1 and sit2 were localized to the plasma membrane in A. fumigatus. The expression levels of the sit1 and sit2 genes were dependent on hapX under low-but not high-iron conditions. Furthermore, mirB, and sidA gene expression was up-regulated and sreA expression down-regulated when sit1 and sit2 were deleted. Although sit1 and sit2 failed to affect mouse survival rate, these genes affected conidial killing activity. Taken together, our results suggest that sit1 and sit2 are siderophore transporters and putative virulence factors localized to the plasma membrane.

scholarly journals The SUMO E3 Ligase MdSIZ1 Targets MdbHLH104 to Regulate Plasma Membrane H+-ATPase Activity and Iron Homeostasis

2018 ◽  
Vol 179 (1) ◽  
pp. 88-106 ◽  
Author(s):  
Li-Jie Zhou ◽  
Chun-Ling Zhang ◽  
Rui-Fen Zhang ◽  
Gui-Luan Wang ◽  
Yuan-Yuan Li ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Iron Homeostasis ◽  
E3 Ligase ◽  
Sumo E3 Ligase

scholarly journals A glycine-specific N-degron pathway mediates the quality control of protein N-myristoylation

Science ◽  
2019 ◽  
Vol 365 (6448) ◽  
pp. eaaw4912 ◽  
Author(s):  
Richard T. Timms ◽  
Zhiqian Zhang ◽  
David Y. Rhee ◽  
J. Wade Harper ◽  
Itay Koren ◽  
...  
Keyword(s):  
Quality Control ◽  
Protein Stability ◽  
Protein Degradation ◽  
E3 Ligase ◽  
Cleavage Sites ◽  
Caspase Cleavage ◽  
E3 Ligases ◽  
Ring E3 Ligase ◽  
The Stability ◽  
Ring E3

The N-terminal residue influences protein stability through N-degron pathways. We used stability profiling of the human N-terminome to uncover multiple additional features of N-degron pathways. In addition to uncovering extended specificities of UBR E3 ligases, we characterized two related Cullin-RING E3 ligase complexes, Cul2ZYG11B and Cul2ZER1, that act redundantly to target N-terminal glycine. N-terminal glycine degrons are depleted at native N-termini but strongly enriched at caspase cleavage sites, suggesting roles for the substrate adaptors ZYG11B and ZER1 in protein degradation during apoptosis. Furthermore, ZYG11B and ZER1 were found to participate in the quality control of N-myristoylated proteins, in which N-terminal glycine degrons are conditionally exposed after a failure of N-myristoylation. Thus, an additional N-degron pathway specific for glycine regulates the stability of metazoan proteomes.

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