scholarly journals Adaptor linked K63 di-Ubiquitin activates Nedd4/Rsp5 E3 ligase

2021 ◽  
Author(s):  
Lu Zhu ◽  
Qing Zhang ◽  
Ciro Cordeiro ◽  
Sudeep Banjade ◽  
Richa Sardana ◽  
...  
Keyword(s):  
E3 Ligase ◽  
Adaptor Proteins ◽  
Regulation Mechanism ◽  
Hect Domain ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Protein Ubiquitination ◽  
Cargo Protein ◽  
Py Motif ◽  
Substrate Induction

Nedd4/Rsp5 family E3 ligases mediate numerous cellular processes, many of which require the E3 ligase to interact with PY-motif containing adaptor proteins. Several Arrestin-Related Trafficking adaptors(ARTs) of Rsp5 were self-ubiquitinated for activation, but the regulation mechanism remains elusive. Remarkably, we demonstrate that Art1, Art4, and Art5 undergo K63-linked di-ubiquitination by Rsp5. This modification enhances the PM recruitment of Rsp5 by Art1 or Art5 upon substrate induction, required for cargo protein ubiquitination. In agreement with these observations, we find that di-ubiquitin strengthens the interaction between the Pombe orthologs of Rsp5 and Art1, Pub1 and Any1. Further, we discover that the HECT domain exosite protects the K63-linked di-ubiquitin on the adaptors from cleavage by the deubiquitination enzyme Ubp2. Strikingly, loss of this protection results in the loss of K63-linked di-ubiquitin from the adaptors and diverts the adaptors for K48-linked poly-ubiquitination and proteasome-mediated degradation. Together, our study uncovers a novel ubiquitination modification implemented by Rsp5 adaptor proteins, underscoring the regulatory mechanism of how adaptor proteins control the recruitment and activity of Rsp5 for the turnover of membrane proteins.  

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 Regulation of Rho GTPases in the Vasculature by Cullin3-Based E3 Ligase Complexes

2021 ◽  
Vol 9 ◽  
Author(s):  
Fabienne Podieh ◽  
Peter L. Hordijk
Keyword(s):  
Rho Gtpases ◽  
Vascular Function ◽  
Rho Gtpase ◽  
Current Knowledge ◽  
E3 Ligase ◽  
Small Gtpases ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Ubiquitin E3 Ligase ◽  
Cytoskeletal Dynamics

Cullin3-based ubiquitin E3 ligases induce ubiquitination of substrates leading to their proteasomal or lysosomal degradation. BTB proteins serve as adaptors by binding to Cullin3 and recruiting substrate proteins, which enables specific recognition of a broad spectrum of targets. Hence, Cullin3 and its adaptors are involved in myriad cellular processes and organ functions. Cullin3-based ubiquitin E3 ligase complexes target small GTPases of the Rho subfamily, which are key regulators of cytoskeletal dynamics and cell adhesion. In this mini review, we discuss recent insights in Cullin3-mediated regulation of Rho GTPases and their impact on cellular function and disease. Intriguingly, upstream regulators of Rho GTPases are targeted by Cullin3 complexes as well. Thus, Rho GTPase signaling is regulated by Cullin3 on multiple levels. In addition, we address current knowledge of Cullin3 in regulating vascular function, focusing on its prominent role in endothelial barrier function, angiogenesis and the regulation of blood pressure.

scholarly journals WW domain–mediated regulation and activation of E3 ubiquitin ligase Suppressor of Deltex

2018 ◽  
Vol 293 (43) ◽  
pp. 16697-16708 ◽  
Author(s):  
Weiyi Yao ◽  
Zelin Shan ◽  
Aihong Gu ◽  
Minjie Fu ◽  
Zhifeng Shi ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Cell Cycle Progression ◽  
Regulatory Mechanism ◽  
Cycle Progression ◽  
Hect Domain ◽  
Ww Domain ◽  
Ww Domains ◽  
E3 Ligases ◽  
Regulation Of Cell Cycle ◽  
Py Motif

The Nedd4 family E3 ligases Itch and WWP1/2 play crucial roles in the regulation of cell cycle progression and apoptosis and are closely correlated with cancer development and metastasis. It has been recently shown that the ligase activities of Itch and WWP1/2 are tightly regulated, with the HECT domain sequestered intramolecularly by a linker region connecting WW2 and WW3. Here, we show that a similar autoinhibitory mechanism is utilized by the Drosophila ortholog of Itch and WWP1/2, Suppressor of Deltex (Su(dx)). We show that Su(dx) adopts an inactive steady state with the WW domain region interacting with the HECT domain. We demonstrate that both the linker and preceding WW2 are required for the efficient binding and regulation of Su(dx) HECT. Recruiting the multiple-PY motif–containing adaptor dNdfip via WW domains relieves the inhibitory state of Su(dx) and leads to substrate (e.g. Notch) ubiquitination. Our study demonstrates an evolutionarily conservative mechanism governing the regulation and activation of some Nedd4 family E3 ligases. Our results also suggest a dual regulatory mechanism for specific Notch down-regulation via dNdfip–Su(dx)–mediated Notch ubiquitination.

scholarly journals Structural Diversity of Ubiquitin E3 Ligase

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6682
Author(s):  
Sachiko Toma-Fukai ◽  
Toshiyuki Shimizu
Keyword(s):  
E3 Ligase ◽  
Structural Diversity ◽  
Biological Processes ◽  
Post Translational Modification ◽  
Post Translational Modifications ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Ubiquitin E3 Ligase ◽  
Ubiquitin Ligase E3 ◽  
Ubiquitin Conjugating Enzyme

The post-translational modification of proteins regulates many biological processes. Their dysfunction relates to diseases. Ubiquitination is one of the post-translational modifications that target lysine residue and regulate many cellular processes. Three enzymes are required for achieving the ubiquitination reaction: ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), and ubiquitin ligase (E3). E3s play a pivotal role in selecting substrates. Many structural studies have been conducted to reveal the molecular mechanism of the ubiquitination reaction. Recently, the structure of PCAF_N, a newly categorized E3 ligase, was reported. We present a review of the recent progress toward the structural understanding of E3 ligases.

scholarly journals Calcineurin-dependent regulation of endocytosis by a plasma membrane ubiquitin ligase adaptor, Rcr1

2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Lu Zhu ◽  
Richa Sardana ◽  
Daniel K. Jin ◽  
Scott D. Emr
Keyword(s):  
Plasma Membrane ◽  
Ubiquitin Ligase ◽  
Adaptor Proteins ◽  
Cell Integrity ◽  
Calcium Treatment ◽  
Cellular Processes ◽  
Acute Response ◽  
Exogenous Calcium ◽  
Sorting Motif ◽  
Py Motif

Rsp5, the Nedd4 family member in yeast, is an E3 ubiquitin ligase involved in numerous cellular processes, many of which require Rsp5 to interact with PY-motif containing adaptor proteins. Here, we show that two paralogous transmembrane Rsp5 adaptors, Rcr1 and Rcr2, are sorted to distinct cellular locations: Rcr1 is a plasma membrane (PM) protein, whereas Rcr2 is sorted to the vacuole. Rcr2 is delivered to the vacuole using ubiquitin as a sorting signal. Rcr1 is delivered to the PM by the exomer complex using a newly uncovered PM sorting motif. Further, we show that Rcr1, but not Rcr2, is up-regulated via the calcineurin/Crz1 signaling pathway. Upon exogenous calcium treatment, Rcr1 ubiquitinates and down-regulates the chitin synthase Chs3. We propose that the PM-anchored Rsp5/Rcr1 ubiquitin ligase-adaptor complex can provide an acute response to degrade unwanted proteins under stress conditions, thereby maintaining cell integrity.

E3 ubiquitin ligases

2005 ◽  
Vol 41 ◽  
pp. 15-30 ◽  
Author(s):  
Helen C. Ardley ◽  
Philip A. Robinson
Keyword(s):  
Protein Complexes ◽  
Loss Of Function ◽  
Direct Role ◽  
Cellular Processes ◽  
Substrate Protein ◽  
Protein Ubiquitination ◽  
C Terminus ◽  
Full Complement ◽  
Spatio Temporal ◽  
Eukaryotic Organisms

The selectivity of the ubiquitin–26 S proteasome system (UPS) for a particular substrate protein relies on the interaction between a ubiquitin-conjugating enzyme (E2, of which a cell contains relatively few) and a ubiquitin–protein ligase (E3, of which there are possibly hundreds). Post-translational modifications of the protein substrate, such as phosphorylation or hydroxylation, are often required prior to its selection. In this way, the precise spatio-temporal targeting and degradation of a given substrate can be achieved. The E3s are a large, diverse group of proteins, characterized by one of several defining motifs. These include a HECT (homologous to E6-associated protein C-terminus), RING (really interesting new gene) or U-box (a modified RING motif without the full complement of Zn2+-binding ligands) domain. Whereas HECT E3s have a direct role in catalysis during ubiquitination, RING and U-box E3s facilitate protein ubiquitination. These latter two E3 types act as adaptor-like molecules. They bring an E2 and a substrate into sufficiently close proximity to promote the substrate's ubiquitination. Although many RING-type E3s, such as MDM2 (murine double minute clone 2 oncoprotein) and c-Cbl, can apparently act alone, others are found as components of much larger multi-protein complexes, such as the anaphase-promoting complex. Taken together, these multifaceted properties and interactions enable E3s to provide a powerful, and specific, mechanism for protein clearance within all cells of eukaryotic organisms. The importance of E3s is highlighted by the number of normal cellular processes they regulate, and the number of diseases associated with their loss of function or inappropriate targeting.

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 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 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.

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