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Vascular homeostasis and pathophysiology are tightly regulated by mechanical forces generated by hemodynamics. Vascular disorders such as atherosclerotic diseases largely occur at curvatures and bifurcations where disturbed blood flow activates endothelial cells while unidirectional flow at the straight part of vessels promotes endothelial health. Integrated analysis of the endothelial transcriptome, the 3D epigenome, and human genetics systematically identified the SNP-enriched cistrome in vascular endothelium subjected to well-defined atherosclerosis-prone disturbed flow or atherosclerosis-protective unidirectional flow. Our results characterized the endothelial typical- and super-enhancers and underscored the critical regulatory role of flow-sensitive endothelial super-enhancers. CRISPR interference and activation validated the function of a previously unrecognized unidirectional flow-induced super-enhancer that upregulates antioxidant genes NQO1, CYB5B, and WWP2, and a disturbed flow-induced super-enhancer in endothelium which drives prothrombotic genes EDN1 and HIVEP in vascular endothelium. Our results employing multiomics identify the cis-regulatory architecture of the flow-sensitive endothelial epigenome related to atherosclerosis and highlight the regulatory role of super-enhancers in mechanotransduction mechanisms. Show less

Accurate modelling of molecular changes in Alzheimer's disease (AD) dementia is crucial for understanding the mechanisms driving neuronal pathology and for developing treatments. Synaptic dysfunction has long been implicated as a mechanism underpinning memory dysfunction in AD and may result in part from changes in adenosine deaminase acting on RNA (ADAR) mediated RNA editing of the GluA2 subunit of AMPA receptors and changes in AMPA receptor function at the post synaptic cleft. However, few studies have investigated changes in proteins which influence RNA editing and notably, AD studies that focus on studying changes in protein expression, rather than changes in mRNA, often use traditional western blotting. Here, we demonstrate the value of automated capillary western blotting to investigate the protein expression of AMPA receptor subunits (GluA1-4), the ADAR RNA editing proteins (ADAR1-3), and proteins known to regulate RNA editing (PIN1, WWP2, FXR1P, and CREB1), in the J20 AD mouse model. We describe extensive optimisation and validation of the automated capillary western blotting method, demonstrating the use of total protein to normalise protein load, in addition to characterising the optimal protein/antibody concentrations to ensure accurate protein quantification. Following this, we assessed changes in proteins of interest in the hippocampus of 44-week-old J20 AD mice. We observed an increase in the expression of ADAR1 p110 and GluA3 and a decrease in ADAR2 in the hippocampus of 44-week-old J20 mice. These changes signify a shift in the balance of proteins that play a critical role at the synapse. Regression analysis revealed unique J20-specific correlations between changes in AMPA receptor subunits, ADAR enzymes, and proteins that regulate ADAR stability in J20 mice, highlighting potential mechanisms mediating RNA-editing changes found in AD. Our findings in J20 mice generally reflect changes seen in the human AD brain. This study underlines the importance of novel techniques, like automated capillary western blotting, to assess protein expression in AD. It also provides further evidence to support the hypothesis that a dysregulation in RNA editing-related proteins may play a role in the initiation and/or progression of AD. Show less

The α-arrestin ARRDC3 is a recently discovered tumor suppressor in invasive breast cancer that functions as a multifaceted adaptor protein to control protein trafficking and cellular signaling. However, the molecular mechanisms that control ARRDC3 function are unknown. Other arrestins are known to be regulated by posttranslational modifications, suggesting that ARRDC3 may be subject to similar regulatory mechanisms. Here we report that ubiquitination is a key regulator of ARRDC3 function and is mediated primarily by two proline-rich PPXY motifs in the ARRDC3 C-tail domain. Ubiquitination and the PPXY motifs are essential for ARRDC3 function in regulating GPCR trafficking and signaling. Additionally, ubiquitination and the PPXY motifs mediate ARRDC3 protein degradation, dictate ARRDC3 subcellular localization, and are required for interaction with the NEDD4-family E3 ubiquitin ligase WWP2. These studies demonstrate a role for ubiquitination in regulating ARRDC3 function and reveal a mechanism by which ARRDC3 divergent functions are controlled. Show less

To explore the co-expression network of the osteoarthritis (OA) risk gene WWP2 in articular cartilage and study cartilage characteristics when mimicking the effect of OA risk allele rs1052429-A on WWP2 expression in a human 3D in vitro model of cartilage. Co-expression behavior of WWP2 with genes expressed in lesioned OA articular cartilage (N = 35 samples) was explored. By applying lentiviral particle mediated WWP2 upregulation in 3D in vitro pellet cultures of human primary chondrocytes (N = 8 donors) the effects of upregulation on cartilage matrix deposition was evaluated. Finally, we transfected primary chondrocytes with miR-140 mimics to evaluate whether miR-140 and WWP2 are involved in similar pathways. Upon performing Spearman correlations in lesioned OA cartilage, 98 highly correlating genes (|ρ| > 0.7) were identified. Among these genes, we identified GJA1, GDF10, STC2, WDR1, and WNK4. Subsequent upregulation of WWP2 on 3D chondrocyte pellet cultures resulted in a decreased expression of COL2A1 and ACAN and an increase in EPAS1 expression. Additionally, we observed a decreased expression of GDF10, STC2, and GJA1. Proteomics analysis identified 42 proteins being differentially expressed with WWP2 upregulation, which were enriched for ubiquitin conjugating enzyme activity. Finally, upregulation of miR-140 in 2D chondrocytes resulted in significant upregulation of WWP2 and WDR1. Mimicking the effect of OA risk allele rs1052429-A on WWP2 expression initiates detrimental processes in the cartilage shown by a response in hypoxia associated genes EPAS1, GDF10, and GJA1 and a decrease in anabolic markers, COL2A1 and ACAN. Show less

This study was conducted to examine the associations between genome-wide association studies (GWAS)-important single nucleotide polymorphisms (SNPs) and knee osteoarthritis (KOA) among Europeans of Russia. The present replicative study ("patient-control" design has been used) was carried out on 1000 DNA samples from KOA ( Show less

Thousands of years of natural and artificial selection since the domestication of the horse has shaped the distinctive genomes of Chinese Mongolian horse populations. Consequently, genomic signatures of selection can provide insights into the human-mediated selection history of specific traits and evolutionary adaptation to diverse environments. Here, we used genome-wide SNPs from five distinct Chinese Mongolian horse populations to identify genomic regions under selection for the population-specific traits, gait, black coat colour, and hoof quality. Other global breeds were used to identify regional-specific signatures of selection. We first identified the most significant selection peak for the Wushen horse in the region on ECA23 harbouring DMRT3, the major gene for gait. We detected selection signatures encompassing several genes in the Baicha Iron Hoof horse that represent good biological candidates for hoof health, including the CSPG4, PEAK1, EXPH5, WWP2 and HAS3 genes. In addition, an analysis of regional subgroups (Asian compared to European) identified a single locus on ECA3 containing the ZFPM1 gene that is a marker of selection for the major domestication event leading to the DOM2 horse clade. Genomic variation at these loci in the Baicha Iron Hoof may be leveraged in other horse populations to identify animals with superior hoof health or those at risk of hoof-related pathologies. The overlap between the selection signature in Asian horses with the DOM2 selection peak raises questions about the nature of horse domestication events, which may have involved a prehistoric clade other than DOM2 that has not yet been identified. Show less

WW domain containing E3 ubiquitin protein ligase 2 (WWP2) is a member of the NEDD4 E3 ubiquitin ligase family. WWP2 ligase activity is regulated by the 2, 3-linker auto-inhibition. Tyrosine phosphorylation of the 2, 3-linker was identified as an activating means for releasing the auto-inhibition of WWP2. However, the tyrosine kinase (TK) for the phosphorylation and activation remains unknown. In this report, we have found that non-receptor TK ACK1 binds to the WW3 domain of WWP2 and phosphorylates WWP2. ACK1 phosphorylates WWP2 at the 2, 3-linker and partially activates the ubiquitination ligase activity. Unexpectedly, tyrosine phosphorylation of the 2, 3-linker seems not a major mode for activation of WWP2, as ACK1 causes much higher activation of the 2, 3-linker tyrosine phosphorylation defective mutants of WWP2 than that of wild-type WWP2. Furthermore, epidermal growth factor (EGF) stimulates tyrosine phosphorylation of WWP2 and this EGF-stimulated phosphorylation of WWP2 is mediated by ACK1. Finally, knockdown of WWP2 by shWWP2 inhibits the EGF-dependent cell proliferation of lung cancer A549 cells, suggesting that WWP2 may function in the EGFR signaling in lung cancer progression. Taken together, our findings have revealed a novel mechanism underlying activation of WWP2. Show less

Large tumor suppressor kinase 1 (LATS1), one of the predominant components of the Hippo pathway, has been characterized as a key player controlling the proliferation and invasion of cancer cells, including gastric cancer (GC) cells. However, the mechanism by which the functional stability of LATS1 is modulated has yet to be elucidated. Online prediction tools, immunohistochemistry and western blotting assays were used to explore the expression of WW domain-containing E3 ubiquitin ligase 2 (WWP2) in GC cells and tissues. Gain- and loss-of-function assays, as well as rescue experiments were performed to determine the role of the WWP2-LATS1 axis in cell proliferation and invasion. Additionally, the mechanisms involving WWP2 and LATS1 were assessed by coimmunoprecipitation (Co-IP), immunofluorescence, cycloheximide and in vivo ubiquitination assays. Our results demonstrate a specific interaction between LATS1 and WWP2. WWP2 was markedly upregulated and correlated with disease progression and a poor prognosis in GC patients. Moreover, ectopic WWP2 expression facilitated the proliferation, migration and invasion of GC cells. Mechanistically, WWP2 interacts with LATS1, resulting in its ubiquitination and subsequent degradation, leading to increased transcriptional activity of YAP1. Importantly, LATS1 depletion abolished the suppressive effects of WWP2 knockdown on GC cells. Furthermore, WWP2 silencing attenuated tumor growth by regulating the Hippo-YAP1 pathway in vivo. Our results define the WWP2-LATS1 axis as a critical regulatory mechanism of the Hippo-YAP1 pathway that promotes GC development and progression. Video Abstract. Show less

Microglia express phosphatidylinositol 3-kinase (PI3K) has been implicated in the induction and maintenance of long-term potentiation (LTP) and in hippocampal synaptic plasticity. However, there are few studies on the interference of PI3K signal pathway in microglia. The study goal is to gain a better understanding of the mechanism by which EA affects synapses provides insights into how electroacupuncture (EA) modulates synaptic plasticity in learning and memory. Rat models of posttraumatic stress disorder (PTSD) were used to explore the effects of EA on microglial PI3K pathway, brain-derived neurotrophic factor (BDNF) and LTP, and the target and mechanism underlying the effects of EA on PI3K from the perspective of protein ubiquitination. EA induced microglial BDNF expression by activating the PI3K-AKT pathway, thereby facilitating LTP and synaptic plasticity. EA inhibited lincRNA 02023 to rescue the binding of WWP2 to PTEN, thereby promoting PTEN ubiquitination and degradation. The mechanism of EA improving the learning and memory ability of PTSD rats may be that it can promote the competitive combination of WWP2 and PTEN by inhibiting Linc RNA02023, and then lead to microglial PI3K and its pathway activation, BDNF up-regulation, and finally induce LTP and repair damaged synaptic plasticity. Show less

Endothelial injury caused by Type 2 diabetes mellitus (T2DM) is considered as a mainstay in the pathophysiology of diabetic vascular complications (DVCs). However, the molecular mechanism of T2DM-induced endothelial injury remains largely unknown. Here, we found that endothelial WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) act as a novel regulator for T2DM-induced vascular endothelial injury through modulating ubiquitination and degradation of DEAD-box helicase 3 X-linked (DDX3X). Single-cell transcriptome analysis was used to evaluate WWP2 expression in vascular endothelial cells of T2DM patients and healthy controls. Endothelial-specific Wwp2 knockout mice were used to investigate the effect of WWP2 on T2DM-induced vascular endothelial injury. In vitro loss- and gain-of-function studies were performed to assess the function of WWP2 on cell proliferation and apoptosis of human umbilical vein endothelial cells. The substrate protein of WWP2 was verified using mass spectrometry, coimmunoprecipitation assays and immunofluorescence assays. The mechanism of WWP2 regulation on substrate protein was investigated by pulse-chase assay and ubiquitination assay. The expression of WWP2 was significantly down-regulated in vascular endothelial cells during T2DM. Endothelial-specific Wwp2 knockout in mice significantly aggravated T2DM-induced vascular endothelial injury and vascular remodeling after endothelial injury. Our in vitro experiments showed that WWP2 protected against endothelial injury by promoting cell proliferation and inhibiting apoptosis in ECs. Mechanically, we found that WWP2 is down-regulated in high glucose and palmitic acid (HG/PA)-induced ECs due to c-Jun N-terminal kinase (JNK) activation, and uncovered that WWP2 suppresses HG/PA-induced endothelial injury by catalyzing K63-linked polyubiquitination of DDX3X and targeting it for proteasomal degradation. Our studies revealed the key role of endothelial WWP2 and the fundamental importance of the JNK-WWP2-DDX3X regulatory axis in T2DM-induced vascular endothelial injury, suggesting that WWP2 may serve as a new therapeutic target for DVCs. Show less

As a widely used lipid-lowering drug in clinical practice, atorvastatin is widely recognized for its role in protecting vascular endothelium in the cardiovascular system. However, a clear mechanistic understanding of its action is lacking. Here, we found that atorvastatin counteracted angiotensin II-induced vascular endothelial injury in mice with hypertension. Mechanistically, atorvastatin up-regulated WWP2, a E6AP C-terminus (HECT)-type E3 ubiquitin ligase with an essential role in regulating protein ubiquitination and various biological processes, thereby rescuing vascular endothelial injury. By ubiquitinating ATP5A (ATP synthase mitochondrial F1 complex subunit alpha), WWP2 degraded ATP5A via the proteasome pathway, stabilizing Bcl-2/Bax in the mitochondrial pathway of apoptosis. Moreover, atorvastatin further ameliorated death of vascular endothelial cells and improved vascular endothelial functions under WWP2 overexpression, whereas WWP2 knockout abrogated these beneficial effects of atorvastatin. Furthermore, we generated endothelial cell-specific WWP2 knockout mice, and this WWP2-mediated mechanism was faithfully recapitulated in vivo. Thus, we propose that activation of a WWP2-dependent pathway that is pathologically repressed in damaged vascular endothelium under hypertension is a major mechanism of atorvastatin. Our findings are also pertinent to develop novel therapeutic strategies for vascular endothelial injury-related cardiovascular diseases. Show less

Immune-checkpoint blockade has revolutionized cancer treatment, but some cancers, such as acute myeloid leukemia (AML), do not respond or develop resistance. A potential mode of resistance is immune evasion of T cell immunity involving aberrant major histocompatibility complex class I (MHC-I) antigen presentation (AP). To map such mechanisms of resistance, we identified key MHC-I regulators using specific peptide-MHC-I-guided CRISPR-Cas9 screens in AML. The top-ranked negative regulators were surface protein sushi domain containing 6 (SUSD6), transmembrane protein 127 (TMEM127), and the E3 ubiquitin ligase WWP2. SUSD6 is abundantly expressed in AML and multiple solid cancers, and its ablation enhanced MHC-I AP and reduced tumor growth in a CD8 Show less

Osteoarthritis (OA) is a common degenerative joint disease and causes chronic pain and disability to the elderly. Several risk factors are involved, such as aging, obesity, genetic susceptibility, and environmental factors. We conducted a transcriptome-wide association study (TWAS) and chemical-related gene set enrichment analysis (CGSEA) to investigate the susceptibility genes and environmental factors. TWAS analysis was conducted to identify the susceptibility genes by integrating the summary-level genome-wide association study data of knee OA (KOA) and hip OA (HOA) with the precomputed expression weights from the Genotype-Tissue Expression Project (Version 8). The FUSION software was used for both single-tissue and cross-tissue TWAS, which were combined using an aggregate Cauchy association test. The biological function and pathways of the TWAS genes were explored using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases, and the human cartilage mRNA expression profiles were utilized to validate the TWAS genes. CGSEA analysis was performed to scan the OA-associated chemicals by integrating the TWAS results with the chemical-related gene sets. There were 44 and 93 unique TWAS genes identified in 7 and 11 chromosomes for KOA and HOA, respectively, fourteen and four of which showed significantly differential expression in the mRNA profiles, such as CRHR1, LTBP1, WWP2, LMX1B, and PTHLH. OA-related pathways were found in the KEGG and GO analysis, such as TGF-beta signaling pathway, MAPK signaling pathway, hyaluronan metabolic process, and chondrocyte differentiation. Forty-five OA-associated chemicals were identified, including quercetin, bisphenol A, and cadmium chloride. Several candidate OA-associated genes and chemicals were identified through TWAS and CGSEA analysis, which expanded our understanding of the relationship between genes, chemicals, and their impact on OA. Show less

Notch has been implicated in human cancers and is a putative therapeutic target. However, the regulation of Notch activation in the nucleus remains largely uncharacterized. Therefore, characterizing the detailed mechanisms governing Notch degradation will identify attractive strategies for treating Notch-activated cancers. Here, we report that the long noncoding RNA (lncRNA) Show less

Blood flow produces shear stress exerted on the endothelial layer of the vessels. Spatial characterization of the endothelial proteome is required to uncover the mechanisms of endothelial activation by shear stress, as blood flow varies in the vasculature. An integrative ubiquitinome and proteome analysis of shear-stressed endothelial cells demonstrated that the non-degradative ubiquitination of several GTPases is regulated by mechano-signaling. Spatial analysis reveals increased ubiquitination of the small GTPase RAP1 in the descending aorta, a region exposed to laminar shear stress. The ubiquitin ligase WWP2 is identified as a novel regulator of RAP1 ubiquitination during shear stress response. Non-degradative ubiquitination fine-tunes the function of GTPases by modifying their interacting network. Specifically, WWP2-mediated RAP1 ubiquitination at lysine 31 switches the balance from the RAP1/ Talin 1 (TLN1) toward RAP1/ Afadin (AFDN) or RAP1/ RAS Interacting Protein 1 (RASIP1) complex formation, which is essential to suppress shear stress-induced reactive oxygen species (ROS) production and maintain endothelial barrier integrity. Increased ROS production in endothelial cells in the descending aorta of endothelial-specific Wwp2-knockout mice leads to increased levels of oxidized lipids and inflammation. These results highlight the importance of the spatially regulated non-degradative ubiquitination of GTPases in endothelial mechano-activation. Show less

WWP2 is a HECT E3 ligase that targets protein Lys residues for ubiquitination and is comprised of an N-terminal C2 domain, four central WW domains, and a C-terminal catalytic HECT domain. The peptide segment between the middle WW domains, the 2,3-linker, is known to autoinhibit the catalytic domain, and this autoinhibition can be relieved by phosphorylation at Tyr369. Several protein substrates of WWP2 have been identified, including the tumor suppressor lipid phosphatase PTEN, but the full substrate landscape and biological functions of WWP2 remain to be elucidated. Here, we used protein microarray technology and the activated enzyme phosphomimetic mutant WWP2 Show less

PCBP-1, a multifunctional RNA binding protein, is expressed in various human cell/tissue types and involved in post-transcriptional gene regulation. PCBP-1 has important roles in cellular Iron homeostasis, mitochondrial stability, and other cellular activities involved in the pathophysiological process of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). However, it remains enigmatic whether PCPB-1 is associated with the pathogenesis of PD. In this study, we cloned and constitutively overexpressed PCBP-1 in rat PC12 cells (PC12 cell is the common cell line studying neurodegenerative disease include PD). RNA-seq was performed to analyze PCBP-1-regulated differentially expressed genes (DEGs) and alternative splicing events (ASEs) between control and PCBP1-overexpressed cells. GO and KEGG pathway analyses were performed to identify functional DEGs and alternatively spliced genes. Consequently, we validated PCBP-1-regulated genes using RT-qPCR. Finally, we downloaded CLIP-seq data from GEO (GSE84700) to analyze the mechanisms of PCBP-1's regulation of gene expression and ASEs by revealing the binding profile of PCBP-1 on its target pre-mRNAs. Overexpression of PCBP-1 partially regulated the ASE and expression of genes enriched in neuroinflammation and protein ubiquitination, which were also associated with PD pathogenesis. Moreover, RT-qPCR assay verified the PCBP-1-modulated expression of neuroinflammatory genes, like Show less

WWP2 is a HECT-type E3 ubiquitin ligase that regulates various physiological and pathological activities by binding to different substrates, but its role in atherosclerosis (AS) remains largely unknown. The objective of the present study is to investigate the role and underlying molecular mechanisms of WWP2 in endothelial injury. We found that WWP2 expression is significantly decreased in Apolipoprotein E (ApoE) Show less

Elimination of autoreactive developing B cells is an important mechanism to prevent autoantibody production. However, how B cell receptor (BCR) signaling triggers apoptosis of immature B cells remains poorly understood. We show that BCR stimulation up-regulates the expression of the lysosomal-associated transmembrane protein 5 (LAPTM5), which in turn triggers apoptosis of immature B cells through two pathways. LAPTM5 causes BCR internalization, resulting in decreased phosphorylation of SYK and ERK. In addition, LAPTM5 targets the E3 ubiquitin ligase WWP2 for lysosomal degradation, resulting in the accumulation of its substrate PTEN. Elevated PTEN levels suppress AKT phosphorylation, leading to increased FOXO1 expression and up-regulation of the cell cycle inhibitor p27Kip1 and the proapoptotic molecule BIM. In vivo, LAPTM5 is involved in the elimination of autoreactive B cells and its deficiency exacerbates autoantibody production. Our results reveal a previously unidentified mechanism that contributes to immature B cell apoptosis and B cell tolerance. Show less

Intervertebral disc degeneration (IDD) development is regulated by miRNA, including inflammatory reactions, cell apoptosis, and degradation of extracellular matrix. Nucleus pulposus cells apoptosis has a absolute influence in the development of IDD. This experiment explores the mechanism of miR-328-5p regulating IDD. Through the analysis of miRNA and mRNA microarray database, we screened the target genes miR-328-5p and WWP2. We verified the expression of miR-328-5p, WWP2, and related apoptotic genes in normal and degenerative nucleus pulposus tissues by qRT-PCR. The expressions of WWP2, Bcl-2, and Bax were detected by qRT-PCR and western blot after transfection to nucleus pulposus cell. The nucleus pulposus cell proliferation and apoptosis after transfection were confirmed by CCK8 and flow cytometry. Luciferase reporter assay and bioinformatics analyzed the targeting relationship between miR-328-5p and WWP2. Firstly, the qRT-PCR experiments confirmed the significant increase of miR-328-5p expression, while significant reduction of WWP2 in a degenerative tissues compared to the normal tissues. Surprisingly, miR-328-5p expression was positively, while that of WWP2 negatively correlated with the degeneration grade of IDD. And we also identified the high expression of Bax and Caspase3, while low expression of Bcl-2 in a degenerative tissues. After miR-328-5p mimic transfected into nucleus pulposus cell, qRT-PCR and western blot confirmed that WWP2 and Bcl-2 expressions were downregulated, while Bax and Caspase3 expressions were upregulated, and the same results were obtained by knocking down WWP2. CCK8 and flow cytometry confirmed that miR-328-5p inhibited the proliferation and induced apoptosis of nucleus pulposus cells. WWP2 is a target gene of miR-328-5p by bioinformatics and luciferase reporter assay. In summary, miR-328-5p targets WWP2 to regulate nucleus pulposus cells apoptosis and then participates in the development of IDD. Furthermore, this study may provide new references and ideas for IDD treatment. Show less

Acute lymphoblastic leukemia (ALL) has been a huge threat for people's health and finding effective target therapy is urgent and important. WWP2, as one of E3 ubiquitin ligase, is involved in many biological processes by specifically binding to substrates. PARP1 plays a role in cell apoptosis and is considered as a therapeutic target of certain cancers. In this study, we firstly found that WWP2 expressed higher in newly diagnosed ALL patients comparing with complete remission (CR) ALL patients and normal control people, and WWP2 in relapse ALL patients expressed higher than normal control people. WWP2 expression was related with the FAB subtype of ALL and the proportion of blast cells in bone marrow blood tested by flow cytometry. We demonstrated knockout WWP2 inhibited the ALL growth and enhanced apoptosis induced by Dox in vitro and vivo for the first time. WWP2 negatively regulated and interacted with PARP1 and WWP2 mechanically degraded PARP1 through polyubiquitin-proteasome pathway in ALL. These findings suggested WWP2 played a role in ALL development as well as growth and apoptosis, and also displayed a regulatory pathway of PARP1, which provided a new potential therapeutic target for the treatment of ALL. Show less

Dishvelled-2 (Dvl2) is an essential component of Wnt pathway, which controls several cell fate decisions during development, such as proliferation, survival and differentiation. Dvl2 forms higher-order protein assemblies in the cell that are critical for relaying the signal from upstream Wnt ligand-frizzled receptor binding to downstream effector β-catenin activation. However, the precise molecular nature and contribution of Dvl2 protein assemblies during Wnt signalling is unknown. Here, we show that Dvl2 forms protein condensates driven by liquid-liquid phase separation. An intrinsically disordered region (IDR) at the N-terminus is essential for Dvl2 phase separation. Importantly, we identified the HECT-E3 ligase WWP2 as an essential driver of Dvl2 phase separation in vitro and in cells. We demonstrated that ubiquitylation of Dvl2 through K63 linkage by WWP2 is required for formation of Dvl2 condensates. Phase-separated Dvl2 activates Wnt signaling by sequestering the components of destruction complex and thus relieving β-catenin. Together, our results reveal a ubiquitylation-dependent liquid-liquid phase separation as a new process through which Dvl2 forms condensates, which is necessary for transduction of Wnt signalling. This article has an associated First Person interview with the first author of the paper. Show less

Non-ischemic cardiomyopathy (NICM) can cause left ventricular dysfunction through interstitial fibrosis, which corresponds to the failure of cardiac tissue remodeling. Recent evidence implicates monocytes/macrophages in the etiopathology of cardiac fibrosis, but giving their heterogeneity and the antagonizing roles of macrophage subtypes in fibrosis, targeting these cells has been challenging. Here we focus on WWP2, an E3 ubiquitin ligase that acts as a positive genetic regulator of human and murine cardiac fibrosis, and show that myeloid specific deletion of WWP2 reduces cardiac fibrosis in hypertension-induced NICM. By using single cell RNA sequencing analysis of immune cells in the same model, we establish the functional heterogeneity of macrophages and define an early pro-fibrogenic phase of NICM that is driven by Ccl5-expressing Ly6c Show less

Hepatocellular carcinoma (HCC) is a common liver cancer that accounts for 90% of cases. Doxorubicin exhibits a broad spectrum of antitumor activity and is one of the most active agents in HCC. WW domain-containing protein 2 (WWP2) is highly expressed in HCC tissues and activates protein kinase B (AKT) signaling pathway to enhance tumor metastasis. However, the role of WWP2 in the glycolysis and antitumor effects of doxorubicin and the epigenetic alterations of WWP2 in HCC remain to be elucidated. The levels of WWP2 and N6-methyladenosine methyltransferase-like 3 (METTL3) in clinical samples and cells were investigated. WWP2 were silenced or overexpressed to study the role of WWP2 in regulating cell proliferation, colony formation, and glycolysis. RNA immunoprecipitation was performed to test m Show less

Organotropism during cancer metastasis occurs frequently but the underlying mechanism remains poorly understood. Here, we show that lysosomal protein transmembrane 5 (LAPTM5) promotes lung-specific metastasis in renal cancer. LAPTM5 sustains self-renewal and cancer stem cell-like traits of renal cancer cells by blocking the function of lung-derived bone morphogenetic proteins (BMPs). Mechanistic investigations showed that LAPTM5 recruits WWP2, which binds to the BMP receptor BMPR1A and mediates its lysosomal sorting, ubiquitination and ultimate degradation. BMPR1A expression was restored by the lysosomal inhibitor chloroquine. LAPTM5 expression could also serve as an independent predictor of lung metastasis in renal cancer. Lastly, elevation of LAPTM5 expression in lung metastases is a common phenomenon in multiple cancer types. Our results reveal a molecular mechanism underlying lung-specific metastasis and identify LAPTM5 as a potential therapeutic target for cancers with lung metastasis. Show less

WW domain-containing E3 Ubiquitin-protein ligase 2 (WWP2) has been found to positively regulate odontoblastic differentiation by monoubiquitinating the transcription factor Kruppel-like factor 5 (KLF5) in a cell culture system. However, the in vivo role of WWP2 in mouse teeth remains unknown. To explore this, here we generated Wwp2 knockout (Wwp2 KO) mice. We found that molars in Wwp2 KO mice exhibited thinner dentin, widened predentin, and reduced numbers of dentinal tubules. In addition, expression of the odontoblast differentiation markers Dspp and Dmp1 was decreased in the odontoblast layers of Wwp2 KO mice. These findings demonstrate that WWP2 may facilitate odontoblast differentiation and dentinogenesis. Furthermore, we show for the first time that phosphatase and tensin homolog (PTEN), a tumor suppressor, is expressed in dental papilla cells and odontoblasts of mouse molars and acts as a negative regulator of odontoblastic differentiation. Further investigation indicated that PTEN is targeted by WWP2 for degradation during odontoblastic differentiation. We demonstrate PTEN physically interacts with and inhibits the transcriptional activity of KLF5 on Dspp and Dmp1. Finally, we found WWP2 was able to suppress the interaction between PTEN and KLF5, which diminished the inhibition effect of PTEN on KLF5. Taken together, this study confirms the essential role of WWP2 and the WWP2-PTEN-KLF5 signaling axis in odontoblast differentiation and dentinogenesis in vivo. Show less

Homologous to E6AP carboxyl-terminus (HECT)-type E3 ligase performs ubiquitin (Ub)-proteasomal protein degradation via forming a complex with E2∼Ub. Enveloped viruses including SARS-CoV-2 escape from the infected cells by harnessing the E-class vacuolar protein-sorting (ESCRT) machinery and mimic the cellular system through PPAY motif-based linking to HECT Ub ligase activity. In the present study, we have characterized the binding pattern of E2 Show less