New insights into oocyte cytoplasmic lattice-associated proteins.

Oocyte maturation and preimplantation embryo development are critical to successful pregnancy outcomes and the correct establishment and maintenance of genomic imprinting. Thanks to novel technologies and omics studies in human patients and mouse models, the importance of the proteins associated with the cytoplasmic lattices (CPLs), highly abundant structures found in the cytoplasm of mammalian oocytes and preimplantation embryos, in the maternal to zygotic transition is becoming increasingly evident. This review highlights the recent discoveries on the role of these proteins in protein storage and other oocyte cytoplasmic processes, epigenetic reprogramming, and zygotic genome activation (ZGA). A better comprehension of these events may significantly improve clinical diagnosis and pave the way for targeted interventions aiming to correct or mitigate female fertility issues and genomic imprinting disorders.

The maternal protein NLRP5 stabilizes UHRF1 in the cytoplasm: implication for the pathogenesis of multilocus imprinting disturbance.

We have recently discovered that the so-called subcortical maternal complex (SCMC) proteins composing of cytoplasmic lattices are destabilized in Uhrf1 knockout murine fully grown oocytes (FGOs). Here we report that human UHRF1 interacts with human NLRP5 and OOEP, which are core components of the SCMC. Moreover, NLRP5 and OOEP interact with DPPA3, which is an essential factor for exporting UHRF1 from the nucleus to the cytoplasm in oocytes. We identify that NLRP5, not OOEP, stabilizes UHRF1 protein in the cytoplasm utilizing specifically engineered cell lines mimicking UHRF1 status in oocytes and preimplantation embryos. Further, UHRF1 is destabilized both in the cytoplasm and nucleus of Nlrp5 knockout murine FGOs. Since pathogenic variants of the SCMC components frequently cause multilocus imprinting disturbance and UHRF1 is essential for maintaining CpG methylation of imprinting control regions during preimplantation development, our results suggest possible pathogenesis behind the disease, which has been a long-standing mystery.

PRAMEL7 and CUL2 decrease NuRD stability to establish ground-state pluripotency.

Pluripotency is established in E4.5 preimplantation epiblast. Embryonic stem cells (ESCs) represent the immortalization of pluripotency, however, their gene expression signature only partially resembles that of developmental ground-state. Induced PRAMEL7 expression, a protein highly expressed in the ICM but lowly expressed in ESCs, reprograms developmentally advanced ESC+serum into ground-state pluripotency by inducing a gene expression signature close to developmental ground-state. However, how PRAMEL7 reprograms gene expression remains elusive. Here we show that PRAMEL7 associates with Cullin2 (CUL2) and this interaction is required to establish ground-state gene expression. PRAMEL7 recruits CUL2 to chromatin and targets regulators of repressive chromatin, including the NuRD complex, for proteasomal degradation. PRAMEL7 antagonizes NuRD-mediated repression of genes implicated in pluripotency by decreasing NuRD stability and promoter association in a CUL2-dependent manner. Our data link proteasome degradation pathways to ground-state gene expression, offering insights to generate in vitro models to reproduce the in vivo ground-state pluripotency.

Novel candidate metastasis-associated genes for synovial sarcoma.

Synovial sarcoma (SS) is an aggressive soft tissue sarcoma with poor prognosis due to late recurrence and metastasis. Metastasis is an important prognostic factor of SS. This study aimed to identify the core genes and mechanisms associated with SS metastasis. Microarray data for GSE40021 and GSE40018 were obtained from the Gene Expression Omnibus database. 186 differentially expressed genes (DEGs) were identified. The biological functions and signalling pathways closely associated with SS metastasis included extracellular matrix (ECM) organization and ECM-receptor interaction. Gene set enrichment analysis showed that the terms cell cycle, DNA replication, homologous recombination and mismatch repair were significantly enriched in the metastasis group. Weighted gene co-expression network analysis identified the most relevant module and 133 hub genes, and 31 crossover genes were identified by combining DEGs. Subsequently, four characteristic genes, EXO1, NCAPG, POLQ and UHRF1, were identified as potential biomarkers associated with SS metastasis using the least absolute shrinkage and selection operator algorithm and validation dataset verification analysis. Immunohistochemistry results from our cohort of 49 patients revealed visible differences in the expression of characteristic genes between the non-metastatic and metastatic groups. Survival analysis indicated that high expression of characteristic genes predicted poor prognosis. Our data revealed that primary SS samples from patients who developed metastasis showed activated homologous recombination and mismatch repair compared to samples from patients without metastasis. Furthermore, EXO1, NCAPG, POLQ and UHRF1 were identified as potential candidate metastasis-associated genes. This study provides further research insights and helps explore the mechanisms of SS metastasis.

YTHDF1 promotes gallbladder cancer progression via post-transcriptional regulation of the m6A/UHRF1 axis.

Gallbladder cancer is a rare but fatal malignancy. However, the mechanisms underlying gallbladder carcinogenesis and its progression are poorly understood. The function of m6A modification and its regulators was still unclear for gallbladder cancer. The current study seeks to investigate the function of YTH m6A RNA-binding protein 1 (YTHDF1) in gallbladder cancer. Transcriptomic analysis and immunochemical staining of YTHDF1 in gallbladder cancer tissues revealed its upregulation compared to paracancerous tissues. Moreover, YTHDF1 promotes the proliferation assays, Transwell migration assays, and Transwell invasion assays of gallbladder cancer cells in vitro. And it also increased tumour growth in xenograft mouse model and metastases in tail vein injection model in vivo. In vitro, UHRF1 knockdown partly reversed the effects of YTHDF1 overexpression. Mechanistically, dual-luciferase assays proved that YTHDF1 promotes UHRF1 expression via direct binding to the mRNA 3'-UTR in a m6A-dependent manner. Overexpression of YTHDF1 enhanced UHRF1 mRNA stability, as demonstrated by mRNA stability assays, and Co-IP studies confirmed a direct interaction between YTHDF1 and PABPC1. Collectively, these findings provide new insights into the progression of gallbladder cancer as well as a novel post-transcriptional mechanism of YTHDF1 via stabilizing target mRNA.

UHRF1P contributes to IL-17A-mediated systemic lupus erythematosus via UHRF1-MAP4K3 axis.

Inflammatory T cells contribute to the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Analysis of the T-cell transcriptomics data of two independent SLE patient cohorts by three machine learning models revealed the pseudogene UHRF1P as a novel SLE biomarker. The pseudogene-encoded UHRF1P protein was overexpressed in peripheral blood T cells of SLE patients. The UHRF1P protein lacks the amino-terminus of its parental UHRF1 protein, resulting in missing the proteasome-binding ubiquitin-like (Ubl) domain of UHRF1. T-cell-specific UHRF1P transgenic mice manifested the induction of IL-17A and autoimmune inflammation. Mechanistically, UHFR1P prevented UHRF1-induced Lys48-linked ubiquitination and degradation of MAP4K3 (GLK), which is a kinase known to induce IL-17A. Consistently, IL-17A induction and autoimmune phenotypes of UHRF1P transgenic mice were obliterated by MAP4K3 knockout. Collectively, UHRF1P overexpression in T cells inhibits the E3 ligase function of its parental UHRF1 and induces autoimmune diseases.

Inhibition of UHRF1 Improves Motor Function in Mice with Spinal Cord Injury.

Spinal-cord injury (SCI) is a severe condition that can lead to limb paralysis and motor dysfunction, and its pathogenesis is not fully understood. The objective of this study was to characterize the differential gene expression and molecular mechanisms in the spinal cord of mice three days after spinal cord injury. By analyzing RNA sequencing data, we identified differentially expressed genes and discovered that the immune system and various metabolic processes play crucial roles in SCI. Additionally, we identified UHRF1 as a key gene that plays a significant role in SCI and found that SCI can be improved by suppressing UHRF1. These findings provide important insights into the molecular mechanisms of SCI and identify potential therapeutic targets that could greatly contribute to the development of new treatment strategies for SCI.

Globular adiponectin induces esophageal adenocarcinoma cell pyroptosis via the miR-378a-3p/UHRF1 axis.

BACKGROUND: Antiapoptosis is a major factor in the resistance of tumor cells to chemotherapy and radiotherapy. Thus, activation of cell pyroptosis may be an effective option to deal with antiapoptotic cancers such as esophageal adenocarcinoma (EAC). METHODS: Differential expression of ubiquitin-like versus PHD and ring finger structural domain 1 (UHRF1) in EAC and near normal tissues was analyzed, as well as the prognostic impact on survival in EAC. Also, the same study was done for globular adiponectin (gAD). Simultaneously, the mRNA expression of UHRF1 was observed in different EAC cell lines. Real time cellular analysis (RTCA) was used to detect cell proliferation, and flow cytometry and inverted fluorescence microscopy were used to detect pyroptosis. Biocredit analysis was conducted to observe the correlation between UHRF1 and key pyroptosis proteins. OD values and CCK8 assay were used to determine the effect of miR-378a-3p on EAC cells. Quantitative real-time polymerase chain reaction and Western blot were used to detect the correlation between UHRF1, gAD, and miR-378a-3p in EAC cells. Moreover, in vivo and in vitro experiments were performed to detect the relevant effects on tumor migration and invasion after inhibiting UHRF1 expression. RESULTS: UHRF1 was negatively correlated with the survival of patients with EAC, while miR-378a-3p showed the opposite effect. Additionally, gAD promoted EAC cell pyroptosis, upregulated miR-378a-3p, and significantly inhibited the proliferation of EAC cells. gAD directly reduced UHRF1 expression in EAC cells by upregulating miR-378a-3p. In cell migration and invasion assays, inhibition of UHRF1 expression significantly suppressed EAC cell metastasis. In animal experiments, we again demonstrated that gAD induced pyroptosis in EAC cells by inhibiting the expression of UHRF1. CONCLUSION: gAD-induced upregulation of miR-378a-3p significantly inhibited the proliferation of EAC by targeting UHRF1. Therefore, gAD may serve as an alternative therapy for chemotherapy- and radiation-refractory EAC or other cancers with the same mechanism of pyroptosis action.

Oncogenic Roles of UHRF1 in Cancer.

Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an essential protein involved in the maintenance of repressive epigenetic marks, ensuring epigenetic stability and fidelity. As an epigenetic regulator, UHRF1 comprises several functional domains (UBL, TTD, PHD, SRA, RING) that are collectively responsible for processes like DNA methylation, histone modification, and DNA repair. UHRF1 is a downstream effector of the RB/E2F pathway, which is nearly universally deregulated in cancer. Under physiological conditions, UHRF1 protein levels are cell cycle-dependent and are post-translationally regulated by proteasomal degradation. Conversely, UHRF1 is overexpressed and serves as an oncogenic driver in multiple cancers. This review focuses on the functional domains of UHRF1, highlighting its key interacting proteins and oncogenic roles in solid tumors including retinoblastoma, osteosarcoma, lung cancer, and breast cancer. Additionally, current therapeutic strategies targeting UHRF1 domains or its interactors are explored, providing an insight on potential clinical applications.

Roles of post-translational modifications of UHRF1 in cancer.

UHRF1 as a member of RING-finger type E3 ubiquitin ligases family, is an epigenetic regulator with five structural domains. It has been involved in the regulation of a series of biological functions, such as DNA replication, DNA methylation, and DNA damage repair. Additionally, aberrant overexpression of UHRF1 has been observed in over ten cancer types, indicating that UHRF1 is a typical oncogene. The overexpression of UHRF1 repressed the transcription of such tumor-suppressor genes as CDKN2A, BRCA1, and CDH1 through DNMT1-mediated DNA methylation. In addition to the upstream transcription factors regulating gene transcription, post-translational modifications (PTMs) also contribute to abnormal overexpression of UHRF1 in cancerous tissues. The types of PTM include phosphorylation, acetylation, methylationand ubiquitination, which regulate protein stability, histone methyltransferase activity, intracellular localization and the interaction with binding partners. Recently, several novel PTM types of UHRF1 have been reported, but the detailed mechanisms remain unclear. This comprehensive review summarized the types of UHRF1 PTMs, as well as their biological functions. A deep understanding of these crucial mechanisms of UHRF1 is pivotal for the development of novel UHRF1-targeted anti-cancer therapeutic strategies in the future.

UHRF1 inhibition mitigates vascular endothelial cell injury and ameliorates atherosclerosis in mice via regulating the SMAD7/YAP1 axis.

BACKGROUND: Endothelial cell injury and dysfunction lead to cholesterol and lipid accumulation and atherosclerotic plaque formation in the arterial wall during atherosclerosis (AS) progression, Ubiquitin-like containing PHD and RING finger domain 1 (UHRF1), a DNA methylation regulator, was strongly upregulated in atherosclerotic plaque lesions in mice. This study aimed to investigate the precise biological functions and regulatory mechanisms of UHRF1 on endothelial dysfunction during AS development. METHODS: UHRF1 levels in the atherosclerotic plaque tissues and normal arterial intima from AS patients were tested with Western blot analysis and immunohistochemistry assays. Human umbilical vein endothelial cells (HUVECs) were stimulated with oxidized low-density lipoprotein (ox-LDL) to induce an injury model and then transfected with short hairpin RNA targeting UHRF1 (sh-UHRF1). Cell proliferation, migration, apoptosis, the levels of inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and the protein levels adhesion molecules including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were measured. Moreover, co-immunoprecipitation assay was used to determine the interactions between UHRF1 and DNA methyltransferases 1 (DNMT1), As well as mothers against DPP homolog 7 (SMAD7) and yes-associated protein 1 (YAP1). SMAD7 promoter methylation was examined with methylation-specific PCR. In addition, we established an AS mouse model to determine the in vivo effects of UHRF1 on AS progression. RESULTS: UHRF1 was upregulated in atherosclerotic plaque tissues and ox-LDL-treated HUVECs. UHRF1 knockdown mitigated ox-LDL-induced proliferation and migration inhibition, apoptosis and the production of TNF-α, IL-6, VCAM-1, and ICAM-1 in HUVECs. Mechanistically, UHRF1 promoted DNMT1-mediated SMAD7 promoter methylation and inhibited its expression. SMAD7 knockdown abolished the protective effects of UHRF1 knockdown on ox-LDL-induced HUVEC injury. Moreover, SMAD7 interacted with YAP1 and inhibited YAP1 expression by promoting YAP1 protein ubiquitination-independent degradation in HUVECs. YAP1 overexpression abrogated SMAD7 overexpression-mediated protective effects on ox-LDL-induced HUVEC injury. Finally, UHRF1 knockdown alleviated atherosclerotic plaque deposition and arterial lesions in AS mice. CONCLUSION: UHRF1 inhibition mitigates vascular endothelial cell injury and ameliorates AS progression in mice by regulating the SMAD7/YAP1 axis.

RepEnTools: an automated repeat enrichment analysis package for ChIP-seq data reveals hUHRF1 Tandem-Tudor domain enrichment in young repeats.

BACKGROUND: Repeat elements (REs) play important roles for cell function in health and disease. However, RE enrichment analysis in short-read high-throughput sequencing (HTS) data, such as ChIP-seq, is a challenging task. RESULTS: Here, we present RepEnTools, a software package for genome-wide RE enrichment analysis of ChIP-seq and similar chromatin pulldown experiments. Our analysis package bundles together various software with carefully chosen and validated settings to provide a complete solution for RE analysis, starting from raw input files to tabular and graphical outputs. RepEnTools implementations are easily accessible even with minimal IT skills (Galaxy/UNIX). To demonstrate the performance of RepEnTools, we analysed chromatin pulldown data by the human UHRF1 TTD protein domain and discovered enrichment of TTD binding on young primate and hominid specific polymorphic repeats (SVA, L1PA1/L1HS) overlapping known enhancers and decorated with H3K4me1-K9me2/3 modifications. We corroborated these new bioinformatic findings with experimental data by qPCR assays using newly developed primate and hominid specific qPCR assays which complement similar research tools. Finally, we analysed mouse UHRF1 ChIP-seq data with RepEnTools and showed that the endogenous mUHRF1 protein colocalizes with H3K4me1-H3K9me3 on promoters of REs which were silenced by UHRF1. These new data suggest a functional role for UHRF1 in silencing of REs that is mediated by TTD binding to the H3K4me1-K9me3 double mark and conserved in two mammalian species. CONCLUSIONS: RepEnTools improves the previously available programmes for RE enrichment analysis in chromatin pulldown studies by leveraging new tools, enhancing accessibility and adding some key functions. RepEnTools can analyse RE enrichment rapidly, efficiently, and accurately, providing the community with an up-to-date, reliable and accessible tool for this important type of analysis.

Prevotella copri exhausts intrinsic indole-3-pyruvic acid in the host to promote breast cancer progression: inactivation of AMPK via UHRF1-mediated negative regulation.

Emerging evidence has revealed the novel role of gut microbiota in the development of cancer. The characteristics of function and composition in the gut microbiota of patients with breast cancer patients has been reported, however the detailed causation between gut microbiota and breast cancer remains uncertain. In the present study, 16S rRNA sequencing revealed that Prevotella, particularly the dominant species Prevotella copri, is significantly enriched and prevalent in gut microbiota of breast cancer patients. Prior-oral administration of P. copri could promote breast cancer growth in specific pathogen-free mice and germ-free mice, accompanied with sharp reduction of indole-3-pyruvic acid (IPyA). Mechanistically, the present of excessive P. copri consumed a large amount of tryptophan (Trp), thus hampering the physiological accumulation of IPyA in the host. Our results revealed that IPyA is an intrinsic anti-cancer reagent in the host at physiological level. Briefly, IPyA directly suppressed the transcription of UHRF1, following by the declined UHRF1 and PP2A C in nucleus, thus inhibiting the phosphorylation of AMPK, which is just opposite to the cancer promoting effect of P. copri. Therefore, the exhaustion of IPyA by excessive P. copri strengthens the UHRF1-mediated negative control to inactivated the energy-controlling AMPK signaling pathway to promote tumor growth, which was indicated by the alternation in pattern of protein expression and DNA methylation. Our findings, for the first time, highlighted P. copri as a risk factor for the progression of breast cancer.

The dopamine receptor D1 inhibitor, SKF83566, suppresses GBM stemness and invasion through the DRD1-c-Myc-UHRF1 interactions.

BACKGROUND: Extensive local invasion of glioblastoma (GBM) cells within the central nervous system (CNS) is one factor that severely limits current treatments. The aim of this study was to uncover genes involved in the invasion process, which could also serve as therapeutic targets. For the isolation of invasive GBM cells from non-invasive cells, we used a three-dimensional organotypic co-culture system where glioma stem cell (GSC) spheres were confronted with brain organoids (BOs). Using ultra-low input RNA sequencing (ui-RNA Seq), an invasive gene signature was obtained that was exploited in a therapeutic context. METHODS: GFP-labeled tumor cells were sorted from invasive and non-invasive regions within co-cultures. Ui-RNA sequencing analysis was performed to find a gene cluster up-regulated in the invasive compartment. This gene cluster was further analyzed using the Connectivity MAP (CMap) database. This led to the identification of SKF83566, an antagonist of the D1 dopamine receptor (DRD1), as a candidate therapeutic molecule. Knockdown and overexpression experiments were performed to find molecular pathways responsible for the therapeutic effects of SKF83566. Finally, the effects of SKF83566 were validated in orthotopic xenograft models in vivo. RESULTS: Ui-RNA seq analysis of three GSC cell models (P3, BG5 and BG7) yielded a set of 27 differentially expressed genes between invasive and non-invasive cells. Using CMap analysis, SKF83566 was identified as a selective inhibitor targeting both DRD1 and DRD5. In vitro studies demonstrated that SKF83566 inhibited tumor cell proliferation, GSC sphere formation, and invasion. RNA sequencing analysis of SKF83566-treated P3, BG5, BG7, and control cell populations yielded a total of 32 differentially expressed genes, that were predicted to be regulated by c-Myc. Of these, the UHRF1 gene emerged as the most downregulated gene following treatment, and ChIP experiments revealed that c-Myc binds to its promoter region. Finally, SKF83566, or stable DRD1 knockdown, inhibited the growth of orthotopic GSC (BG5) derived xenografts in nude mice. CONCLUSIONS: DRD1 contributes to GBM invasion and progression by regulating c-Myc entry into the nucleus that affects the transcription of the UHRF1 gene. SKF83566 inhibits the transmembrane protein DRD1, and as such represents a candidate small therapeutic molecule for GBMs.

Identification of ubiquitination-related hub genes in chronic myeloid leukemia cell by bioinformatics analysis.

Purpose: Chronic myeloid leukemia stem cells (CML-LSCs) are posited as the primary instigators of resistance to tyrosine kinase inhibitors (TKIs) and recurrence of CML. Ubiquitination, a post-translational modification, has been implicated in the worsening process of CML. A more detailed understanding of their crosstalk needs further investigation. Our research aims to explore the potential ubiquitination-related genes in CML-LSC using bioinformatics analysis that might be the target for the eradication of LSCs. Methods: The ubiquitination modification-related differentially expressed genes (UUC-DEGs) between normal hematopoietic stem cells (HSCs) and LSCs were obtained from GSE47927 and iUUCD database. Subsequently, the hub UUC-DEGs were identified through protein-protein interaction (PPI) network analysis utilizing the STRING database and the MCODE plug-in within the Cytoscape platform. The upstream regulation network of the hub UUC-DEGs was studied by hTFtarget, PROMO, miRDB and miRWalk databases respectively. Then the correlation between the hub UUC-DEGs and the immune cells was analyzed by the CIBERSORT algorithm and "ggcorrplot" package. Finally, we validated the function of hub UUC-DEGs in CML animal models, CML cell lines and CD34+ cells of the GSE24739 dataset. Results: There is a strong association between the 4 hub UUC genes (AURKA, Fancd2, Cdc20 and Uhrf1) of LSCs and the infiltration of CD4+/CD8+ T cells, NK cells and monocytes. 8 TFs and 23 miRNAs potentially targeted these 4 hub genes were constructed. Among these hub genes, Fancd2, Cdc20 and Uhrf1 were found to be highly expressed in CML-LSC, which knocking down resulted in significant inhibition of CML cell proliferation. Conclusions: From the perspective of bioinformatics analysis, UHRF1 and CDC20 were identified as the novel key ubiquitination-related genes in CML-LSCs and the pathogenesis of CML.

MOF-mediated acetylation of UHRF1 enhances UHRF1 E3 ligase activity to facilitate DNA methylation maintenance.

The multi-domain protein UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) recruits DNMT1 for DNA methylation maintenance during DNA replication. Here, we show that MOF (males absent on the first) acetylates UHRF1 at K670 in the pre-RING linker region, whereas HDAC1 deacetylates UHRF1 at the same site. We also identify that K667 and K668 can also be acetylated by MOF when K670 is mutated. The MOF/HDAC1-mediated acetylation in UHRF1 is cell-cycle regulated and peaks at G1/S phase, in line with the function of UHRF1 in recruiting DNMT1 to maintain DNA methylation. In addition, UHRF1 acetylation significantly enhances its E3 ligase activity. Abolishing UHRF1 acetylation at these sites attenuates UHRF1-mediated H3 ubiquitination, which in turn impairs DNMT1 recruitment and DNA methylation. Taken together, these findings identify MOF as an acetyltransferase for UHRF1 and define a mechanism underlying the regulation of DNA methylation maintenance through MOF-mediated UHRF1 acetylation.

UHRF1 poly-auto-ubiquitination induced by the anti-cancer drug, thymoquinone, is involved in the DNA repair machinery recruitment.

DNA methylation is one of the most important epigenetic mark involved in many physiologic cellular processes and pathologies. During mitosis, the transmission of DNA methylation patterns from a mother to the daughter cells is ensured through the action of the Ubiquitin-like, containing PHD and RING domains, 1/DNA methyltransferase 1 (UHRF1/DNMT1) tandem. UHRF1 is involved in the silencing of many tumor suppressor genes (TSGs) via mechanisms that remain largely to be deciphered. The present study investigated the role and the regulation of UHRF1 poly-ubiquitination induced by thymoquinone, a natural anti-cancer drug, known to enhance or re-activate the expression of TSGs. We found that the auto-ubiquitination of UHRF1, induced by TQ, is mediated by reactive oxygen species, and occurs following DNA damage. We demonstrated that the poly-ubiquitinated form of UHRF1 is K63-linked and can still silence the tumor suppressor gene p16INK4A/CDKN2A. We further showed that TQ-induced auto-ubiquitination is mediated via the activity of Tip60. Since this latter is known as a nuclear receptor co-factor, we investigated if the glucocorticoid receptor (GR) might be involved in the regulation of UHRF1 ubiquitination. Activation of the GR, with dexamethasone, did not influence auto-ubiquitination of UHRF1. However, we could observe that TQ induced a K48-linked poly-ubiquitination of GR, probably involved in the proteosomal degradation pathway. Mass-spectrometry analysis of FLAG-HA-tagged UHRF1 identified UHRF1 partners involved in DNA repair and showed that TQ increased their association with UHRF1, suggesting that poly-ubiquitination of UHRF1 is involved in the DNA repair process. We propose that poly-ubiquitination of UHRF1 serves as a scaffold to recruit the DNA repair machinery at DNA damage sites.

Unveiling dissociation mechanisms and binding patterns in the UHRF1-DPPA3 complex via multi-replica molecular dynamics simulations.

CONTEXT: Ubiquitin-like with PHD and RING finger domain containing protein 1 (UHRF1) is responsible for preserving the stability of genomic methylation through the recruitment of DNA methyltransferase 1 (DNMT1). However, the interaction between Developmental pluripotency associated 3 (DPPA3) and the pre-PHD-PHD (PPHD) domain of UHRF1 hinders the nuclear localization of UHRF1. This disruption has implications for potential cancer treatment strategies. Drugs that mimic the binding pattern between DPPA3 and PPHD could offer a promising approach to cancer treatment. Our study reveals that DPPA3 undergoes dissociation from the C-terminal through three different modes of helix unfolding. Furthermore, we have identified key residue pairs involved in this dissociation process and potential drug-targeting residues. These findings offer valuable insights into the dissociation mechanism of DPPA3 from PPHD and have the potential to inform the design of novel drugs targeting UHRF1 for cancer therapy. METHODS: To comprehend the dissociation process and binding patterns of PPHD-DPPA3, we employed enhanced sampling techniques, including steered molecular dynamics (SMD) and conventional molecular dynamics (cMD). Additionally, we utilized self-organizing maps (SOM) and time-resolved force distribution analysis (TRFDA) methodologies. The Gromacs software was used for performing molecular dynamics simulations, and the AMBER FF14SB force field was applied to the protein.

Circular RNA hsa_circ_0005939 Regulates UHRF1BP1L Expression by Targeting miR-4693-3p to Promote Colorectal Cancer Progression.

INTRODUCTION: Colorectal cancer (CRC) is the second most common and fatal cancer in China. circRNAs are different expressed between tumor and non-tumor tissues, and they are proved to be correlated with tumorigenesis and cancer progression. OBJECTIVE: We aimed to explore the biological and molecular function of hsa_circ_0005939 in CRC. METHODS: We collected and compared ten CRC tissues and four noncancerous tissues and performed circRNA sequencing. We investigated the hsa_circ_0005939 expression in fresh tissues from CRC and adjacent tissues by qPCR. Meanwhile, functional roles of hsa_circ_0005939 in CRC cells were explored by CCK-8, colony formation, wounding healing, cell apoptosis and western blot assays. RNA-FISH was used to confirm the cellular distribution of hsa_circ_0005939. Bioinformatic prediction and luciferase reporter assay were used to determine the mechanisms of hsa_circ_0005939. RESULTS: Our results indicated that hsa_circ_0005939 was up-regulated in CRC tissues and cells. Up-regulation of hsa_circ_0005939 was associated with the occurrence and the number of lymph node metastasis of CRC. Hsa_circ_0005939 down-regulation inhibited cell proliferation, increased cell apoptosis and caused G2 phase arrest of CRC cells. Mechanistically, luciferase assay revealed that hsa_circ_0005939 acts as a molecular sponge for miR-4693-3p and then enhanced Ubiquitin Like With PHD And Ring Finger Domains 1 binding protein 1 like (UHRF1BP1L) expression. CONCLUSION: Our findings indicated an oncogenic role of hsa_circ_0005939 in CRC, and it enhanced malignant phenotypes of CRC cells through miR-4693-3p/UHRF1BP1L axis. Our study may offer promising biomarkers and therapeutic targets for CRC.