Deubiquitinase OTUD5 promotes hepatitis B virus replication by removing K48-linked ubiquitination of HBV core/precore and upregulates HNF4ɑ expressions by inhibiting the ERK1/2/mitogen-activated protein kinase pathway.

Hepatitis B virus (HBV) infection is a major public health problem worldwide, causing nearly one million deaths annually. OTUD5 is a deubiquitinase associated with cancer development and innate immunity response. However, the regulatory mechanisms of OTUD5 underlying HBV replication need to be deeply elucidated. In the present investigation, we found that HBV induced significant up-regulation of OTUD5 protein in HBV-infected cells. Further study showed that OTUD5 interacted with HBV core/precore, removing their K48-linked ubiquitination chains and protecting their stability. Meanwhile, overexpression of OTUD5 could inhibit the MAPK pathway and then increase the expression of HNF4ɑ, and ERK1/2 signaling was required for OTUD5-mediated activation of HNF4α, promoting HBV replication. Together, these data indicate that OTUD5 could deubiquitinate HBV core protein degradation by its deubiquitinase function and promote HBV activity by up-regulating HNF4α expression via inhibition of the ERK1/2 pathway. These results might present a novel therapeutic strategy against HBV infection.

An X-linked syndrome with severe neurodevelopmental delay, hydrocephalus, and early lethality caused by a missense variation in the OTUD5 gene.

We describe an X-linked syndrome in 13 male patients from a single family with three generations affected. Patients presented prenatally or during the neonatal period with intrauterine growth retardation, ventriculomegaly, hydrocephalus, hypotonia, congenital heart defects, hypospadias, and severe neurodevelopmental delay. The disease is typically fatal during infancy, mainly due to sepsis (pneumonias). Female carriers are asymptomatic. We performed genome sequencing in four individuals and identified a unique candidate variant in the OTUD5 gene (NM_017602.3:c.598G > A, p.Glu200Lys). The variant cosegregated with the disease in 10 tested individuals. OTUD5 was considered as a candidate gene based on two previous missense variants detected in patients with intellectual disability. In conclusion, we define a syndrome associated with OTUD5 defects and add compelling evidence of genotype-phenotype association. This finding ended the long diagnostic odyssey of this family.

Dapagliflozin suppressed gastric cancer growth via regulating OTUD5 mediated YAP1 deubiquitination.

Gastric cancer (GC) is a common malignant disease that has a fifth highest incidence and fourth highest mortality worldwide. The Warburg effect is a common phenomenon observed in tumors, which suggests that tumor cells would enhance glucose uptake by overexpressing multiple glucose transporters. Sodium glucose transporter 2 (SGLT2) is one of glucose transporters which highly expressed in several cancers, but its role in gastric cancer is still unclear. Our research found that there was a high expression level of SGLT2 in gastric cancer tissues. We found that Dapagliflozin (a SGLT2 inhibitor) could suppress gastric cancer cell proliferation and migration in vitro and tumor growth in vivo. In present study, we revealed how dapagliflozin would suppress gastric cancer progression in a novel mechanism. We proved that dapagliflozin decreased the expression level of OTU deubiquitinase 5 (OTUD5), which further increased the ubiquitination and degradation of YAP1. Overexpression of OTUD5 in gastric cancer cells partly reversed the anti-tumor effect of dapagliflozin. Our findings revealed a novel mechanism by which dapagliflozin has an antitumor effect on gastric cancer and proposed a beneficial strategy for the application of dapagliflozin in gastric cancer patients.

A novel missense variant in OTUD5 causes X-linked multiple congenital anomalies-neurodevelopmental syndrome.

BACKGROUND: The OTUD5 gene encodes a deubiquitinating enzyme (DUB) of the OTU family. Variants of OTUD5 are associated with X-linked multiple congenital anomalies-neurodevelopmental syndrome (MCAND). The case described in this study expands the clinical and molecular spectrum of OTUD5. METHODS: Trio-based clinical exome sequencing (trio-CES) was performed on a Chinese boy with a clinical phenotype and both of his parents. Sanger sequencing was employed for validation of the variant detected. RESULTS: The patient presented with characteristic facial features, intellectual disability, motor/language/cognitive, and global developmental delays, limb contractures, and kidney abnormalities, and trio-CES identified a de novo missense variant, c.1305T>A, of the OTUD5 gene. DISCUSSION: We describe OTUD5 gene variation in the Chinese population, with the first report of this variant. Additionally, we provide a comprehensive summary of all published cases of MCAND to date, in order to elucidate the primary clinical features of the syndrome and the variability in phenotype severity. This case expands the genetic and clinical phenotypic spectrum of OTUD5-associated MCAND.

The deubiquitinase OTUD5 stabilizes SLC7A11 to promote progression and reduce paclitaxel sensitivity in triple-negative breast cancer.

Ferroptosis is a newly defined form of programmed cell death characterized by iron-dependent lipid peroxide accumulation and is associated with the progression of cancer. Solute carrier family 7 member 11 (SLC7A11), a key component of cystine/glutamate antiporter, has been characterized as a critical regulator of ferroptosis. Although many studies have established the transcriptional regulation of SLC7A11, it remains largely unknown how the stability of SLC7A11 is regulated in cancers, especially in triple-negative breast cancer (TNBC). Here we demonstrated that ovarian tumor domain-containing protein 5 (OTUD5), which deubiquitinated and stabilized SLC7A11, played a key role in TNBC progression and paclitaxel chemosensitivity through modulating ferroptosis. The clinical data analysis showed OTUD5 was higher expressed in TNBC, which positively correlated with SLC7A11 level. Mechanistically, OTUD5 interacted with SLC7A11 and cleaved K48-linked polyubiquitin chains from SLC7A11 to enhance the stability of SLC7A11. Taken together, these findings uncover a functional and mechanistic role of OTUD5 in TNBC progression and paclitaxel sensitivity, indicating OTUD5 could be a potential target for TNBC treatment.

OTUD5 promotes the growth of hepatocellular carcinoma by deubiquitinating and stabilizing SLC38A1.

BACKGROUND: Deubiquitinating enzymes (DUBs) cleave ubiquitin on substrate molecules to maintain protein stability. DUBs reportedly participate in the tumorigenesis and tumour progression of hepatocellular carcinoma (HCC). OTU deubiquitinase 5 (OTUD5), a DUB family member, has been recognized as a critical regulator in bladder cancer, breast cancer and HCC. However, the expression and biological function of OTUD5 in HCC are still controversial. RESULTS: We determined that the expression of OTUD5 was significantly upregulated in HCC tissues. High levels of OTUD5 were also detected in most HCC cell lines. TCGA data analysis demonstrated that high OTUD5 expression indicated poorer overall survival in HCC patients. OTUD5 silencing prominently suppressed HCC cell proliferation, while its overexpression markedly enhanced the proliferation of HCC cells. Mass spectrometry analysis revealed solute carrier family 38 member 1 (SLC38A1) as a candidate downstream target protein of OTUD5. Coimmunoprecipitation analysis confirmed the interaction between OTUD5 and SLC38A1. OTUD5 knockdown reduced and OTUD5 overexpression increased SLC38A1 protein levels in HCC cells. However, OTUD5 alteration had no effect on SLC38A1 mRNA expression. OTUD5 maintained SLC38A1 stability by preventing its ubiquitin-mediated proteasomal degradation. SLC38A1 silencing prominently attenuated the OTUD5-induced increase in HCC cell proliferation. Finally, OTUD5 knockdown markedly suppressed the growth of HCC cells in vivo. CONCLUSIONS: OTUD5 is an oncogene in HCC. OTUD5 contributes to HCC cell proliferation by deubiquitinating and stabilizing SLC38A1. These results may provide a theoretical basis for the development of new anti-HCC drugs.

The Regulation and Double-Edged Roles of the Deubiquitinase OTUD5.

OTUD5 (OTU Deubiquitinase 5) is a functional cysteine protease with deubiquitinase activity and is a member of the ovarian tumor protease (OTU) family. OTUD5 is involved in the deubiquitination of many key proteins in various cellular signaling pathways and plays an important role in maintaining normal human development and physiological functions. Its dysfunction can affect physiological processes, such as immunity and DNA damage repair, and it can even lead to tumors, inflammatory diseases and genetic disorders. Therefore, the regulation of OTUD5 activity and expression has become a hot topic of research. A comprehensive understanding of the regulatory mechanisms of OTUD5 and its use as a therapeutic target for diseases is of great value. Herein, we review the physiological processes and molecular mechanisms of OTUD5 regulation, outline the specific regulatory processes of OTUD5 activity and expression, and link OTUD5 to diseases from the perspective of studies on signaling pathways, molecular interactions, DNA damage repair and immune regulation, thus providing a theoretical basis for future studies.

Deubiquitinase OTUD5 as a Novel Protector against 4-HNE-Triggered Ferroptosis in Myocardial Ischemia/Reperfusion Injury.

Despite the development of advanced technologies for interventional coronary reperfusion after myocardial infarction, a substantial number of patients experience high mortality due to myocardial ischemia-reperfusion (MI/R) injury. An in-depth understanding of the mechanisms underlying MI/R injury can provide crucial strategies for mitigating myocardial damage and improving patient survival. Here, it is discovered that the 4-hydroxy-2-nonenal (4-HNE) accumulates during MI/R, accompanied by high rates of myocardial ferroptosis. The loss-of-function of aldehyde dehydrogenase 2 (ALDH2), which dissipates 4-HNE, aggravates myocardial ferroptosis, whereas the activation of ALDH2 mitigates ferroptosis. Mechanistically, 4-HNE targets glutathione peroxidase 4 (GPX4) for K48-linked polyubiquitin-related degradation, which 4-HNE-GPX4 axis commits to myocyte ferroptosis and forms a positive feedback circuit. 4-HNE blocks the interaction between GPX4 and ovarian tumor (OTU) deubiquitinase 5 (OTUD5) by directly carbonylating their cysteine residues at C93 of GPX4 and C247 of OTUD5, identifying OTUD5 as the novel deubiquitinase for GPX4. Consequently, the elevation of OTUD5 deubiquitinates and stabilizes GPX4 to reverse 4-HNE-induced ferroptosis and alleviate MI/R injury. The data unravel the mechanism of 4-HNE in GPX4-dependent ferroptosis and identify OTUD5 as a novel therapeutic target for the treatment of MI/R injury.

Hypoxia-induced proteasomal degradation of DBC1 by SIAH2 in breast cancer progression.

DBC1 has been characterized as a key regulator of physiological and pathophysiological activities, such as DNA damage, senescence, and tumorigenesis. However, the mechanism by which the functional stability of DBC1 is regulated has yet to be elucidated. Here, we report that the ubiquitination-mediated degradation of DBC1 is regulated by the E3 ubiquitin ligase SIAH2 and deubiquitinase OTUD5 under hypoxic stress. Mechanistically, hypoxia promoted DBC1 to interact with SIAH2 but not OTUD5, resulting in the ubiquitination and subsequent degradation of DBC1 through the ubiquitin-proteasome pathway. SIAH2 knockout inhibited tumor cell proliferation and migration, which could be rescued by double knockout of SIAH2/CCAR2. Human tissue microarray analysis further revealed that the SIAH2/DBC1 axis was responsible for tumor progression under hypoxic stress. These findings define a key role of the hypoxia-mediated SIAH2-DBC1 pathway in the progression of human breast cancer and provide novel insights into the metastatic mechanism of breast cancer.

OTUD5-mediated deubiquitination of YAP in macrophage promotes M2 phenotype polarization and favors triple-negative breast cancer progression.

Macrophages, which are highly plastic, can be polarized to M1 or M2 subtypes according to the diverse signals in complex microenvironment. Studies have shown the activation of YAP, an oncogenic transcriptional co-activator, increased macrophage recruitment. However, its role in macrophage polarization remains to be elucidated, especially in triple-negative breast cancer (TNBC) progression. Here we found TNBC cells increased YAP expression in macrophages, which depended on OTUD5-mediated deubiquitination and stabilization of YAP, then the high expression of YAP polarized macrophage to the M2-like phenotype. Moreover, the elevation of YAP in M2-like macrophage promotes the pro-metastatic potential of TNBC cells via MCP-1/CCR2 pathway. We also observed high expression of YAP in M2 macrophage was negatively related to survival. Collectively, our finding suggested the therapeutic strategy that targets YAP+ M2 macrophage could be a novel option for TNBC treatment.

OTUD5 promotes innate antiviral and antitumor immunity through deubiquitinating and stabilizing STING.

Stimulator of interferon genes (STING) is an adaptor protein that is critical for effective innate antiviral and antitumor immunity. The activity of STING is heavily regulated by protein ubiquitination, which is fine-tuned by both E3 ubiquitin ligases and deubiquitinases. Here, we report that the deubiquitinase OTUD5 interacts with STING, cleaves its K48-linked polyubiquitin chains, and promotes its stability. Consistently, knockout of OTUD5 resulted in faster turnover of STING and subsequently impaired type I IFN signaling following cytosolic DNA stimulation. More importantly, Lyz2-Cre Otud5fl/Y mice and CD11-Cre Otud5fl/Y mice showed more susceptibility to herpes simplex virus type 1 (HSV-1) infection and faster development of melanomas than their corresponding control littermates, indicating that OTUD5 is indispensable for STING-mediated antiviral and antitumor immunity. Our data suggest that OTUD5 is a novel checkpoint in the cGAS-STING cytosolic DNA sensing pathway.

OTUD5 Variants Associated With X-Linked Intellectual Disability and Congenital Malformation.

BACKGROUND: X-linked intellectual disability (XLID), which occurs predominantly in males, is a relatively common and genetically heterogeneous disorder in which over 100 mutated genes have been reported. The OTUD5 gene at Xp11.23 encodes ovarian tumor deubiquitinase 5 protein, which is a deubiquitinating enzyme member of the ovarian tumor family. LINKage-specific-deubiquitylation-deficiency-induced embryonic defects (LINKED) syndrome, arising from pathogenic OTUD5 variants, was recently reported as a new XLID with additional congenital anomalies. METHODS: We investigated three affected males (49- and 47-year-old brothers [Individuals 1 and 2] and a 2-year-old boy [Individual 3]) from two families who showed developmental delay. Their common clinical features included developmental delay, hypotonia, short stature, and distinctive facial features, such as telecanthus and a depressed nasal bridge. Individuals 1 and 2 showed epilepsy and brain magnetic resonance imaging showed a thin corpus callosum and mild ventriculomegaly. Individual 3 showed congenital malformations, including tetralogy of Fallot, hypospadias, and bilateral cryptorchidism. To identify the genetic cause of these features, we performed whole-exome sequencing. RESULTS: A hemizygous OTUD5 missense variant, c.878A>T, p.Asn293Ile [NM_017602.4], was identified in one family with Individuals 1 and 2, and another missense variant, c.1210 C>T, p.Arg404Trp, in the other family with Individual 3, respectively. The former variant has not been registered in public databases and was predicted to be pathogenic by multiple in silico prediction tools. The latter variant p.Arg404Trp was previously reported as a pathogenic OTUD5 variant, and Individual 3 showed a typical LINKED syndrome phenotype. However, Individuals 1 and 2, with the novel variant (p.Asn293Ile), showed no cardiac or genitourinary malformations. CONCLUSIONS: Unlike previous reports of LINKED syndrome, which described early lethality with congenital cardiac anomalies, our three cases are still alive. Notably, the adult brothers with the novel missense OTUD5 variant have lived into their forties. This may be indicative of a milder phenotype as a possible genotype-phenotype correlation. These findings imply a possible long-term prognosis for individuals with this new XLID syndrome, and a wider phenotypic variation than initially thought.

OTU deubiquitinase 5 inhibits the progression of non-small cell lung cancer via regulating p53 and PDCD5.

Non-small cell lung cancer (NSCLC) has the highest morbidity and mortality worldwide. OTU deubiquitinase 5 (OTUD5), a deubiquitinating enzyme, can enhance the stability of p53 and programmed cell death 5 (PDCD5), a protein related to the apoptosis, by deubiquitination. This study aimed to explore the biological function and underlying mechanism of OTUD5 in NSCLC. Western blot and qRT-PCR were used to detect the expression of OTUD5 protein and mRNA in NSCLC tissues and cells, respectively. RNAi was adopted to construct an OTUD5 low-expression model while the plasmids overexpressing p53 and PDCD5 were used to establish the overexpression models, respectively. CCK-8 assay, transwell assay, and apoptosis assay were carried out to analyze the changes in the proliferation, migration, and chemoresistance of A549 and HCC827 cells. The mechanism of OTUD5 in NSCLC was studied by Western blot. Down-regulated OTUD5 in NSCLC tissues was significantly correlated to a poor prognosis. The knockdown of OTUD5 inactivated p53 and PDCD5, promoting the proliferation and metastasis of NSCLC cells while inhibiting their apoptosis. OTUD5 knockdown also enhanced the resistance of NSCLC cells to doxorubicin and cisplatin. OTUD5 acted as a tumor suppressor in NSCLC by regulating the p53 and PDCD5 pathways.

Analysis of deubiquitinase OTUD5 as a biomarker and therapeutic target for cervical cancer by bioinformatic analysis.

OTU deubiquitinase 5 (OTUD5), as a member of the ovarian tumor protease (OTU) family, was previously reported to play important roles in DNA repair and immunity. However, little is known about its function in tumors. Cervical cancer is a malignant tumor that seriously endangers the lives of women. Here, we found that low expression of OTUD5 in cervical cancer is associated with poor prognosis. Its expression is associated with tumor stage, metastatic nodes and tumor subtypes such as those related to the phosphatidylinositol-3-kinase (PI3K)-AKT signaling, epithelial-mesenchymal transition (EMT) and hormones. In addtion, we analyzed the coexpressed genes, related miRNAs, transcription factors, kinases, E3s and interacting proteins of OTUD5. We demonstrated that OTUD5 affects the expression levels of WD repeat domain 45 (WDR45), ubiquitin-specific peptidase 11 (USP11), GRIP1 associated protein 1 (GRIPAP1) and RNA binding motif protein 10 (RBM10). Moreover, hsa-mir-137, hsa-mir-1913, hsa-mir-937, hsa-mir-607, hsa-mir-3149 and hsa-mir-144 may inhibit the expression of OTUD5. Furthermore, we performed enrichment analysis of 22 coexpressed genes, 33 related miRNAs and 30 interacting proteins. In addition to ubiquitination and immunology related processes, they also participate in Hippo signaling, insulin signaling, EMT, histone methylation and phosphorylation kinase binding. Our study for the first time analyzed the expression of OTUD5 in cervical cancer and its relationship with clinicopathology and provided new insights for further study of its regulatory mechanism in tumors.

Deubiquitinase OTUD5 mediates the sequential activation of PDCD5 and p53 in response to genotoxic stress.

Programmed cell death 5 (PDCD5) positively regulates p53-mediated apoptosis and rapidly accumulates upon DNA damage. However, the underlying mechanism of PDCD5 upregulation during the DNA damage response remains unknown. Here, we found that OTU deubiquitinase 5 (OTUD5) was bound to PDCD5 in response to etoposide treatment and increased the stability of PDCD5 by mediating deubiquitination of PDCD5 at Lys-97/98. Overexpression of OTUD5 efficiently enhanced the activation of both PDCD5 and p53. Conversely, PDCD5 knockdown greatly attenuated the effect of OTUD5 on p53 activation. In addition, when OTUD5 was depleted, PDCD5 failed to facilitate p53 activation, demonstrating an essential role for the PDCD5-OTUD5 network in p53 activation. Importantly, we found that OTUD5-dependent PDCD5 stabilization was required for sequential activation of p53 in response to genotoxic stress. The sequential activation of PDCD5 and p53 was abrogated by knockdown of OTUD5. Finally, impairment of the genotoxic stress response upon PDCD5 ablation was substantially rescued by reintroducing PDCD5(WT) but not PDCD5(E94D) (defective for OTUD5 interaction) or PDCD5(E16D) (defective for p53 interaction). Together, our findings have uncovered an apoptotic signaling cascade linking PDCD5, OTUD5, and p53 during genotoxic stress responses.