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1.
Mol Cell ; 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39303720

ABSTRACT

Cys2-His2 zinc-finger proteins (C2H2-ZNFs) constitute the largest class of DNA-binding transcription factors (TFs) yet remain largely uncharacterized. Although certain family members, e.g., GTF3A, have been shown to bind both DNA and RNA, the extent to which C2H2-ZNFs interact with-and regulate-RNA-associated processes is not known. Using UV crosslinking and immunoprecipitation (CLIP), we observe that 148 of 150 analyzed C2H2-ZNFs bind directly to RNA in human cells. By integrating CLIP sequencing (CLIP-seq) RNA-binding maps for 50 of these C2H2-ZNFs with data from chromatin immunoprecipitation sequencing (ChIP-seq), protein-protein interaction assays, and transcriptome profiling experiments, we observe that the RNA-binding profiles of C2H2-ZNFs are generally distinct from their DNA-binding preferences and that they regulate a variety of post-transcriptional processes, including pre-mRNA splicing, cleavage and polyadenylation, and m6A modification of mRNA. Our results thus define a substantially expanded repertoire of C2H2-ZNFs that bind RNA and provide an important resource for elucidating post-transcriptional regulatory programs.

2.
Genome Biol ; 25(1): 246, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39300486

ABSTRACT

BACKGROUND: N6-methyladenosine (m6A), the most abundant internal modification on eukaryotic mRNA, and N6, 2'-O-dimethyladenosine (m6Am), are epitranscriptomic marks that function in multiple aspects of posttranscriptional regulation. Fat mass and obesity-associated protein (FTO) can remove both m6A and m6Am; however, little is known about how FTO achieves its substrate selectivity. RESULTS: Here, we demonstrate that ZBTB48, a C2H2-zinc finger protein that functions in telomere maintenance, associates with FTO and binds both mRNA and the telomere-associated regulatory RNA TERRA to regulate the functional interactions of FTO with target transcripts. Specifically, depletion of ZBTB48 affects targeting of FTO to sites of m6A/m6Am modification, changes cellular m6A/m6Am levels and, consequently, alters decay rates of target RNAs. ZBTB48 ablation also accelerates growth of HCT-116 colorectal cancer cells and modulates FTO-dependent regulation of Metastasis-associated protein 1 (MTA1) transcripts by controlling the binding to MTA1 mRNA of the m6A reader IGF2BP2. CONCLUSIONS: Our findings thus uncover a previously unknown mechanism of posttranscriptional regulation in which ZBTB48 co-ordinates RNA-binding of the m6A/m6Am demethylase FTO to control expression of its target RNAs.


Subject(s)
Adenosine , Alpha-Ketoglutarate-Dependent Dioxygenase FTO , Humans , Adenosine/analogs & derivatives , Adenosine/metabolism , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics , HCT116 Cells , RNA, Messenger/metabolism , RNA, Messenger/genetics , Telomere/metabolism , Telomere/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , Zinc Fingers
3.
Plast Surg (Oakv) ; 32(3): 367-373, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39104933

ABSTRACT

Introduction: Upper limb function loss in cervical spinal cord injury (SCI) contributes to substantial disability, and negatively impacts quality of life. Nerve transfer and tendon transfer surgery can provide improved upper limb function. This study assessed the utilization of nerve and tendon transfer surgery for individuals with tetraplegia in Canada. Methods: Data from the Canadian Institute for Health Information's Discharge Abstracts Database and the National Ambulatory Care Reporting System were used to identify the nerve and tendon transfer procedures performed in individuals with tetraplegia (2004-2020). Cases were identified using cervical SCI ICD-10-CA codes and Canadian Classification of Intervention codes for upper extremity nerve and tendon transfers. Data on sex, age at time of procedure, province, and hospital stay duration were recorded. Results: From 2004 to 2020, there were ≤80 nerve transfer procedures (81% male, mean age 38.3 years) and 61 tendon transfer procedures (78% male, mean age 45.0 years) performed (highest in Ontario and British Columbia). Using an estimate of 50% eligibility, an average of 1.3% of individuals underwent nerve transfer and 1.0% underwent tendon transfer. Nerve transfers increased over time (2004-2009, n = <5; 2010-2015, n = 27; 2016-2019, n = 49) and tendon transfers remained relatively constant. Both transfer types were performed as day-surgery or single night stay. Conclusions: Nerve and tendon transfer surgery to improve upper limb function in Canadians with tetraplegia remains low. This study highlights a substantial gap in care for this vulnerable population. Identification of barriers that prevent access to care is required to promote best practice for upper extremity care.


Introduction : La perte de fonction du membre supérieur en cas de lésion de la moelle épinière cervicale (SCI0 contribue à un handicap substantiel avec des répercussions négatives sur la qualité de vie. La chirurgie de transfert des nerfs et des tendons peut apporter une amélioration du fonctionnement du membre supérieur. Cette étude a évalué l'utilisation de la chirurgie de transfert de nerfs et de tendons pour les patients tétraplégiques au Canada. Méthodes : Des données issues de la base de données des résumés de congés de l'Institut canadien d'information sur la santé du système national d'information sur les soins ambulatoires ont été utilisées pour identifier les procédures de transfert de nerfs et de tendons pratiquées sur des patients tétraplégiques entre 2004 et 2020. Les cas ont été identifiés en utilisant les codes de SCI cervicales du CIM-10-CA et des codes canadiens de classification des interventions pour les transferts de nerfs et de tendons du membre supérieur. Les données sur le sexe et l'âge au moment de la procédure, la province et la durée de séjour à l'hôpital ont été consignées. Résultats : Entre 2004 et 2020, il y a eu ≤ 80 procédures de transferts de nerfs (hommes : 81 %, âge moyen : 38,3 ans) et 61 procédures de transfert de tendons (hommes : 78 %, âge moyen : 45,0 ans) pratiquées (principalement en Ontario et en Colombie-Britannique). En estimant une admissibilité de 50 %, une moyenne de 1,3 % des patients a subi un transfert de nerfs et 1,0 % des patients a subi un transfert tendineux. Les transferts de nerfs ont augmenté au fil des années (2004-2009, n = < 5; 2010-2015, n = 27; 2016-2019, n = 49) tandis que le nombre de transferts tendineux est resté relativement stable. Les deux types de transferts ont été pratiqués das le cadre de la chirurgie d'un jour ou avec une hospitalisation d'une seule nuit. Conclusions : La chirurgie de transfert de nerfs et de tendons pour l'amélioration des fonctions des membres supérieurs reste peu utilisée pour les Canadiens tétraplégiques. Cette étude souligne une lacune substantielle des soins pour cette population vulnérable. Il est nécessaire d'identifier les obstacles qui empêchent l'accès aux soins afin de promouvoir une meilleure pratique pour les soins du membre supérieur.

4.
Nucleic Acids Res ; 52(8): 4483-4501, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38587191

ABSTRACT

Messenger RNA precursors (pre-mRNA) generally undergo 3' end processing by cleavage and polyadenylation (CPA), which is specified by a polyadenylation site (PAS) and adjacent RNA sequences and regulated by a large variety of core and auxiliary CPA factors. To date, most of the human CPA factors have been discovered through biochemical and proteomic studies. However, genetic identification of the human CPA factors has been hampered by the lack of a reliable genome-wide screening method. We describe here a dual fluorescence readthrough reporter system with a PAS inserted between two fluorescent reporters. This system enables measurement of the efficiency of 3' end processing in living cells. Using this system in combination with a human genome-wide CRISPR/Cas9 library, we conducted a screen for CPA factors. The screens identified most components of the known core CPA complexes and other known CPA factors. The screens also identified CCNK/CDK12 as a potential core CPA factor, and RPRD1B as a CPA factor that binds RNA and regulates the release of RNA polymerase II at the 3' ends of genes. Thus, this dual fluorescence reporter coupled with CRISPR/Cas9 screens reliably identifies bona fide CPA factors and provides a platform for investigating the requirements for CPA in various contexts.


Subject(s)
CRISPR-Cas Systems , Genes, Reporter , RNA Precursors , mRNA Cleavage and Polyadenylation Factors , Humans , Cyclin-Dependent Kinases/metabolism , Cyclin-Dependent Kinases/genetics , Genome, Human , HEK293 Cells , mRNA Cleavage and Polyadenylation Factors/metabolism , mRNA Cleavage and Polyadenylation Factors/genetics , Polyadenylation , RNA Cleavage , RNA Polymerase II/metabolism , RNA Precursors/metabolism , RNA Precursors/genetics
5.
PLoS Pathog ; 19(7): e1011477, 2023 07.
Article in English | MEDLINE | ID: mdl-37410772

ABSTRACT

SUMO modifications regulate the function of many proteins and are important in controlling herpesvirus infections. We performed a site-specific proteomic analysis of SUMO1- and SUMO2-modified proteins in Epstein-Barr virus (EBV) latent and lytic infection to identify proteins that change in SUMO modification status in response to EBV reactivation. Major changes were identified in all three components of the TRIM24/TRIM28/TRIM33 complex, with TRIM24 being rapidly degraded and TRIM33 being phosphorylated and SUMOylated in response to EBV lytic infection. Further experiments revealed TRIM24 and TRIM33 repress expression of the EBV BZLF1 lytic switch gene, suppressing EBV reactivation. However, BZLF1 was shown to interact with TRIM24 and TRIM33, resulting in disruption of TRIM24/TRIM28/TRIM33 complexes, degradation of TRIM24 and modification followed by degradation of TRIM33. Therefore, we have identified TRIM24 and TRIM33 as cellular antiviral defence factors against EBV lytic infection and established the mechanism by which BZLF1 disables this defence.


Subject(s)
Epstein-Barr Virus Infections , Humans , Herpesvirus 4, Human/genetics , Trans-Activators/genetics , Trans-Activators/metabolism , Small Ubiquitin-Related Modifier Proteins/metabolism , Proteomics , Virus Activation , Virus Latency , Transcription Factors/metabolism , Carrier Proteins
6.
J Mol Biol ; 435(13): 168128, 2023 07 01.
Article in English | MEDLINE | ID: mdl-37100168

ABSTRACT

SARS-CoV-2 virus spike (S) protein is an envelope protein responsible for binding to the ACE2 receptor, driving subsequent entry into host cells. The existence of multiple disulfide bonds in the S protein makes it potentially susceptible to reductive cleavage. Using a tri-part split luciferase-based binding assay, we evaluated the impacts of chemical reduction on S proteins from different virus variants and found that those from the Omicron family are highly vulnerable to reduction. Through manipulation of different Omicron mutations, we found that alterations in the receptor binding module (RBM) are the major determinants of this vulnerability. Specifically we discovered that Omicron mutations facilitate the cleavage of C480-C488 and C379-C432 disulfides, which consequently impairs binding activity and protein stability. The vulnerability of Omicron S proteins suggests a mechanism that can be harnessed to treat specific SARS-CoV-2 strains.


Subject(s)
Spike Glycoprotein, Coronavirus , Humans , Biological Assay , Mutation , Protein Binding , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Oxidation-Reduction , Protein Stability
7.
Heliyon ; 9(1): e12744, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36597481

ABSTRACT

SARS-CoV-2 depends on host cell components for infection and replication. Identification of virus-host dependencies offers an effective way to elucidate mechanisms involved in viral infection and replication. If druggable, host factor dependencies may present an attractive strategy for anti-viral therapy. In this study, we performed genome wide CRISPR knockout screens in Vero E6 cells and four human cell lines including Calu-3, UM-UC-4, HEK-293 and HuH-7 to identify genetic regulators of SARS-CoV-2 infection. Our findings identified only ACE2, the cognate SARS-CoV-2 entry receptor, as a common host dependency factor across all cell lines, while other host genes identified were largely cell line specific, including known factors TMPRSS2 and CTSL. Several of the discovered host-dependency factors converged on pathways involved in cell signalling, immune-related pathways, and chromatin modification. Notably, the chromatin modifier gene KMT2C in Calu-3 cells had the strongest impact in preventing SARS-CoV-2 infection when perturbed.

8.
Mol Cell ; 82(17): 3135-3150.e9, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35914531

ABSTRACT

Alternative polyadenylation (APA) enhances gene regulatory potential by increasing the diversity of mRNA transcripts. 3' UTR shortening through APA correlates with enhanced cellular proliferation and is a widespread phenomenon in tumor cells. Here, we show that the ubiquitously expressed transcription factor Sp1 binds RNA in vivo and is a common repressor of distal poly(A) site usage. RNA sequencing identified 2,344 genes (36% of the total mapped mRNA transcripts) with lengthened 3' UTRs upon Sp1 depletion. Sp1 preferentially binds the 3' UTRs of such lengthened transcripts and inhibits cleavage at distal sites by interacting with the subunits of the core cleavage and polyadenylation (CPA) machinery. The 3' UTR lengths of Sp1 target genes in breast cancer patient RNA-seq data correlate with Sp1 expression levels, implicating Sp1-mediated APA regulation in modulating tumorigenic properties. Taken together, our findings provide insights into the mechanism for dynamic APA regulation by unraveling a previously unknown function of the DNA-binding transcription factor Sp1.


Subject(s)
Poly A , Polyadenylation , 3' Untranslated Regions , Humans , Poly A/metabolism , RNA, Messenger/metabolism , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/metabolism , Zinc/metabolism
9.
J Mol Biol ; 434(12): 167602, 2022 06 30.
Article in English | MEDLINE | ID: mdl-35469831

ABSTRACT

High performance affinity reagents are essential tools to enable biologists to profile the cellular location and composition of macromolecular complexes undergoing dynamic reorganization. To support further development of such tools, we have assembled a high-throughput phage display pipeline to generate Fab-based affinity reagents that target different dynamic forms of a large macromolecular complex, using the Chromosomal Passenger Complex (CPC), as an example. The CPC is critical for the maintenance of chromosomal and cytoskeleton processes during cell division. The complex contains 4 protein components: Aurora B kinase, survivin, borealin and INCENP. The CPC acts as a node to dynamically organize other partnering subcomplexes to build multiple functional structures during mitotic progression. Using phage display mutagenesis, a cohort of synthetic antibodies (sABs) were generated against different domains of survivin, borealin and INCENP. Immunofluorescence established that a set of these sABs can discriminate between the form of the CPC complex in the midbody versus the spindle. Others localize to targets, which appear to be less organized, in the nucleus or cytoplasm. This differentiation suggests that different CPC epitopes have dynamic accessibility depending upon the mitotic state of the cell. An Immunoprecipitation/Mass Spectrometry analysis was performed using sABs that bound specifically to the CPC in either the midbody or MT spindle macromolecular assemblies. Thus, sABs can be exploited as high performance reagents to profile the accessibility of different components of the CPC within macromolecular assemblies during different stages of mitosis suggesting this high throughput approach will be applicable to other complex macromolecular systems.


Subject(s)
Antibodies , Aurora Kinase B , Cell Cycle Proteins , Chromosomal Proteins, Non-Histone , Immunoglobulin Fab Fragments , Multiprotein Complexes , Survivin , Antibodies/chemistry , Antibodies/genetics , Aurora Kinase B/analysis , Aurora Kinase B/immunology , Cell Cycle Proteins/analysis , Cell Cycle Proteins/immunology , Chromosomal Proteins, Non-Histone/analysis , Chromosomal Proteins, Non-Histone/immunology , Cytoskeleton/metabolism , Humans , Immunoglobulin Fab Fragments/chemistry , Immunoglobulin Fab Fragments/genetics , Mitosis , Multiprotein Complexes/analysis , Multiprotein Complexes/immunology , Peptide Library , Phosphorylation , Spindle Apparatus/metabolism , Survivin/chemistry , Survivin/metabolism
10.
PLoS Pathog ; 18(1): e1010235, 2022 01.
Article in English | MEDLINE | ID: mdl-35007297

ABSTRACT

The Epstein-Barr virus (EBV) BGLF2 protein is a tegument protein with multiple effects on the cellular environment, including induction of SUMOylation of cellular proteins. Using affinity-purification coupled to mass-spectrometry, we identified the miRNA-Induced Silencing Complex (RISC), essential for miRNA function, as a top interactor of BGLF2. We confirmed BGLF2 interaction with the Ago2 and TNRC6 components of RISC in multiple cell lines and their co-localization in cytoplasmic bodies that also contain the stress granule marker G3BP1. In addition, BGLF2 expression led to the loss of processing bodies in multiple cell types, suggesting disruption of RISC function in mRNA regulation. Consistent with this observation, BGLF2 disrupted Ago2 association with multiple miRNAs. Using let-7 miRNAs as a model, we tested the hypothesis that BGLF2 interfered with the function of RISC in miRNA-mediated mRNA silencing. Using multiple reporter constructs with 3'UTRs containing let-7a regulated sites, we showed that BGLF2 inhibited let-7a miRNA activity dependent on these 3'UTRs, including those from SUMO transcripts which are known to be regulated by let-7 miRNAs. In keeping with these results, we showed that BGLF2 increased the cellular level of unconjugated SUMO proteins without affecting the level of SUMO transcripts. Such an increase in free SUMO is known to drive SUMOylation and would account for the effect of BGLF2 in inducing SUMOylation. We further showed that BGLF2 expression inhibited the loading of let-7 miRNAs into Ago2 proteins, and conversely, that lytic infection with EBV lacking BGLF2 resulted in increased interaction of let-7a and SUMO transcripts with Ago2, relative to WT EBV infection. Therefore, we have identified a novel role for BGLF2 as a miRNA regulator and shown that one outcome of this activity is the dysregulation of SUMO transcripts that leads to increased levels of free SUMO proteins and SUMOylation.


Subject(s)
Carboxypeptidases/metabolism , Epstein-Barr Virus Infections/virology , Herpesvirus 4, Human/metabolism , Host-Parasite Interactions/physiology , MicroRNAs/metabolism , Viral Fusion Proteins/metabolism , Cell Line , Epstein-Barr Virus Infections/metabolism , Humans , Sumoylation
11.
Int J Gynecol Cancer ; 32(4): 457-465, 2022 04 04.
Article in English | MEDLINE | ID: mdl-34987097

ABSTRACT

OBJECTIVES: Same day discharge after minimally invasive hysterectomy has been shown to be safe and feasible. We designed and implemented a quality improvement perioperative program based on early recovery after surgery principles to improve the rate of same day discharge from 30% to 75% after minimally invasive gynecologic oncology surgery over a 12 month period. METHODS: We enrolled 102 consecutive patients undergoing minimally invasive hysterectomy at a single cancer center during a 12 month period. A pre-intervention cohort of 100 consecutive patients was identified for comparison of clinicodemographic variables and perioperative outcomes. A multidisciplinary team developed a comprehensive perioperative care program and followed quality improvement methodology. Patients were followed up for 30 days after discharge. A statistical process chart was used to monitor the effects of our interventions, and a multivariate analysis was conducted to determine factors associated with same day discharge. RESULTS: Same day discharge rate increased from 29% to 75% after implementation (p<0.001). The post-intervention cohort was significantly younger (59 vs 62 years; p=0.038) and had shorter operative times (180 vs 211 min; p<0.001) but the two groups were similar in body mass index, comorbidity, stage, and intraoperative complications. There was no difference in 30 day perioperative complications, readmissions, reoperations, emergency department visits, or mortality. Overnight admissions were secondary to nausea and vomiting (16%), complications of pre-existing comorbidities (12%), and urinary retention (8%). On multivariate analysis, longer surgery, timing of surgery, and narcotic use on the ward were significantly associated with overnight admission. Overall, 89% of patients rated their experience as 'very good' or 'excellent', and 87% felt that their length of stay was adequate. CONCLUSIONS: Following implementation of a perioperative quality improvement program targeted towards minimally invasive gynecologic oncology surgery, our intervention significantly improved same day discharge rates while maintaining a low 30 day perioperative complication rate and excellent patient experience.


Subject(s)
Genital Neoplasms, Female , Patient Discharge , Female , Genital Neoplasms, Female/surgery , Humans , Length of Stay , Minimally Invasive Surgical Procedures/methods , Postoperative Complications/epidemiology , Quality Improvement , Retrospective Studies
12.
iScience ; 25(1): 103562, 2022 Jan 21.
Article in English | MEDLINE | ID: mdl-34901782

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein is essential for viral replication, making it a promising target for antiviral drug and vaccine development. SARS-CoV-2 infected patients exhibit an uncoordinated immune response; however, the underlying mechanistic details of this imbalance remain obscure. Here, starting from a functional proteomics workflow, we cataloged the protein-protein interactions of SARS-CoV-2 proteins, including an evolutionarily conserved specific interaction of N with the stress granule resident proteins G3BP1 and G3BP2. N localizes to stress granules and sequesters G3BPs away from their typical interaction partners, thus attenuating stress granule formation. We found that N binds directly to host mRNAs in cells, with a preference for 3' UTRs, and modulates target mRNA stability. We show that the N protein rewires the G3BP1 mRNA-binding profile and suppresses the physiological stress response of host cells, which may explain the imbalanced immune response observed in SARS-CoV-2 infected patients.

13.
Nat Chem Biol ; 18(1): 56-63, 2022 01.
Article in English | MEDLINE | ID: mdl-34782742

ABSTRACT

Nuclear receptor-binding SET domain-containing 2 (NSD2) is the primary enzyme responsible for the dimethylation of lysine 36 of histone 3 (H3K36), a mark associated with active gene transcription and intergenic DNA methylation. In addition to a methyltransferase domain, NSD2 harbors two proline-tryptophan-tryptophan-proline (PWWP) domains and five plant homeodomains (PHDs) believed to serve as chromatin reading modules. Here, we report a chemical probe targeting the N-terminal PWWP (PWWP1) domain of NSD2. UNC6934 occupies the canonical H3K36me2-binding pocket of PWWP1, antagonizes PWWP1 interaction with nucleosomal H3K36me2 and selectively engages endogenous NSD2 in cells. UNC6934 induces accumulation of endogenous NSD2 in the nucleolus, phenocopying the localization defects of NSD2 protein isoforms lacking PWWP1 that result from translocations prevalent in multiple myeloma (MM). Mutations of other NSD2 chromatin reader domains also increase NSD2 nucleolar localization and enhance the effect of UNC6934. This chemical probe and the accompanying negative control UNC7145 will be useful tools in defining NSD2 biology.


Subject(s)
Cell Nucleolus/metabolism , Histone-Lysine N-Methyltransferase/metabolism , Molecular Probes/chemistry , Protein Domains , Repressor Proteins/metabolism , Methylation , Multiple Myeloma/metabolism , Nucleosomes/metabolism
14.
J Pharm Biomed Anal ; 206: 114354, 2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34509663

ABSTRACT

Animal venoms contain many peptides with high specificity and selectivity against their protein targets, a characteristic which makes venoms an invaluable source of potential drugs. High-sensitivity mass spectrometry (MS)- based peptidomic platform has evolved as a predominant method for natural peptide drug discovery due to its strength for direct and rapid identification of peptides and peptide-associated post-translational modifications (PTMs). In this study, we used cell-affinity assays combined with nanoLC-MS/MS based peptidomics to identify cancer cell binding peptides (CBPs) from Bufo Bufo gargarizans. We identified 76 potential cell binding peptides and 237 non-affinity peptides in venom extracts from Asiatic toads, and some were verified with MS-parallel reaction monitoring (PRM) mode. These peptides were further analyzed and internalized within human cells and some demonstrated anti-tumor properties in vitro. These specific peptides might be used as templates for peptide-based drug design or optimization.


Subject(s)
Neoplasms , Tandem Mass Spectrometry , Animals , Bufo bufo , Early Detection of Cancer , Humans , Peptides
15.
Virology ; 562: 103-109, 2021 10.
Article in English | MEDLINE | ID: mdl-34304093

ABSTRACT

Whole genome sequence analysis of Epstein-Barr virus genomes from tumours and healthy individuals identified three amino acid changes in EBNA1 that are strongly associated with gastric carcinoma and nasopharyngeal carcinoma. Here we show that, while these mutations do not impact EBNA1 plasmid maintenance function, one of them (Thr85Ala) decreases transcriptional activation and results in a gain of function interaction with PLOD1 and PLOD3. PLOD family proteins are strongly linked to multiple cancers, and PLOD1 is recognized as a prognostic marker of gastric carcinoma. We identified the PLOD1 binding site in EBNA1as the N-terminal transactivation domain and show that lysine 83 is critical for this interaction. The results provide a novel link between EBV infection and the cancer-associated PLOD proteins.


Subject(s)
Epstein-Barr Virus Infections/virology , Epstein-Barr Virus Nuclear Antigens/metabolism , Herpesvirus 4, Human/genetics , Neoplasms/virology , Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase/metabolism , Binding Sites , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Epstein-Barr Virus Infections/metabolism , Epstein-Barr Virus Nuclear Antigens/genetics , Herpesvirus 4, Human/metabolism , Humans , Mutation , Neoplasms/metabolism , Protein Binding , Transcriptional Activation/genetics
16.
Front Pharmacol ; 12: 664349, 2021.
Article in English | MEDLINE | ID: mdl-34163357

ABSTRACT

COVID-19 mortality is primarily driven by abnormal alveolar fluid metabolism of the lung, leading to fluid accumulation in the alveolar airspace. This condition is generally referred to as pulmonary edema and is a direct consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There are multiple potential mechanisms leading to pulmonary edema in severe Coronavirus Disease (COVID-19) patients and understanding of those mechanisms may enable proper management of this condition. Here, we provide a perspective on abnormal lung humoral metabolism of pulmonary edema in COVID-19 patients, review the mechanisms by which pulmonary edema may be induced in COVID-19 patients, and propose putative drug targets that may be of use in treating COVID-19. Among the currently pursued therapeutic strategies against COVID-19, little attention has been paid to abnormal lung humoral metabolism. Perplexingly, successful balance of lung humoral metabolism may lead to the reduction of the number of COVID-19 death limiting the possibility of healthcare services with insufficient capacity to provide ventilator-assisted respiration.

17.
Nucleic Acids Res ; 49(11): 6196-6212, 2021 06 21.
Article in English | MEDLINE | ID: mdl-34086947

ABSTRACT

Retinoblastoma-binding proteins 4 and 7 (RBBP4 and RBBP7) are two highly homologous human histone chaperones. They function in epigenetic regulation as subunits of multiple chromatin-related complexes and have been implicated in numerous cancers. Due to their overlapping functions, our understanding of RBBP4 and 7, particularly outside of Opisthokonts, has remained limited. Here, we report that in the ciliate protozoan Tetrahymena thermophila a single orthologue of human RBBP4 and 7 proteins, RebL1, physically interacts with histone H4 and functions in multiple epigenetic regulatory pathways. Functional proteomics identified conserved functional links for Tetrahymena RebL1 protein as well as human RBBP4 and 7. We found that putative subunits of multiple chromatin-related complexes including CAF1, Hat1, Rpd3, and MuvB, co-purified with RebL1 during Tetrahymena growth and conjugation. Iterative proteomics analyses revealed that the cell cycle regulatory MuvB-complex in Tetrahymena is composed of at least five subunits including evolutionarily conserved Lin54, Lin9 and RebL1 proteins. Genome-wide analyses indicated that RebL1 and Lin54 (Anqa1) bind within genic and intergenic regions. Moreover, Anqa1 targets primarily promoter regions suggesting a role for Tetrahymena MuvB in transcription regulation. RebL1 depletion inhibited cellular growth and reduced the expression levels of Anqa1 and Lin9. Consistent with observations in glioblastoma tumors, RebL1 depletion suppressed DNA repair protein Rad51 in Tetrahymena, thus underscoring the evolutionarily conserved functions of RBBP4/7 proteins. Our results suggest the essentiality of RebL1 functions in multiple epigenetic regulatory complexes in which it impacts transcription regulation and cellular viability.


Subject(s)
Histone Chaperones/metabolism , Protozoan Proteins/metabolism , Tetrahymena thermophila/metabolism , Amino Acid Sequence , Bacterial Proteins/metabolism , Biological Evolution , Conserved Sequence , DNA/metabolism , DNA-Binding Proteins/metabolism , Epigenesis, Genetic , Gene Expression , HEK293 Cells , Histone Chaperones/chemistry , Histone Chaperones/physiology , Histones/metabolism , Humans , Neoplasms/metabolism , Neoplasms/mortality , Oncogenes , Protozoan Proteins/chemistry , Protozoan Proteins/physiology , Retinoblastoma-Binding Protein 4/metabolism , Retinoblastoma-Binding Protein 7/metabolism , Tetrahymena thermophila/genetics , Tetrahymena thermophila/growth & development
18.
Front Pediatr ; 8: 558, 2020.
Article in English | MEDLINE | ID: mdl-33014941

ABSTRACT

Background: Non-neurogenic urinary and fecal incontinence (UI, FI) affects approximately 6% of North American children with 1% of cases becoming refractory (nonresponsive to standard therapies). Incontinence has major potential long-term physiological and psychological implications for patients and their families. While Sacral Neuromodulation (SNM) and Transcutaneous Nerve Stimulation (TENS) are alternative therapies available for the treatment of refractory UI/FI, these are not approved for use in children in Canada. The present study assessed participants' perception of current treatments, incontinence burden, and attitudes toward novel therapies in a single pediatric institution. Methods: Multiple validated questionnaires including Dysfunctional Voiding Scoring System (DVSS), Bristol Stool Chart (BSC), Pediatric Incontinence measurement (PinQ), and Time-Driven Activity Based Costing were used to perform a needs assessment for patients with non-neurogenic refractory incontinence, and to determine patients' and caregivers' attitudes toward alternative therapies. Results: 75% of patients and 89% of caregivers reported a moderate to severe impact of incontinence on QoL with diminished social interactions among the primary concerns. Caregivers were frustrated with current treatments and were open to trying alternative therapies (SNM and TENS), which, at least in the case of SNM, seems to be less expensive, possibly less burdensome and more effective than current surgical options. Conclusion: Pediatric refractory UI/FI has a large impact on patients' and caregivers' QoL and alternative therapies with the potential to improve QoL of patients and caregivers should be further investigated as a substitute for surgery.

19.
Sci Rep ; 9(1): 15664, 2019 Oct 25.
Article in English | MEDLINE | ID: mdl-31653879

ABSTRACT

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

20.
J Virol ; 93(22)2019 11 15.
Article in English | MEDLINE | ID: mdl-31462557

ABSTRACT

The BMRF1 protein of Epstein-Barr virus (EBV) has multiple roles in viral lytic infection, including serving as the DNA polymerase processivity factor, activating transcription from several EBV promoters and inhibiting the host DNA damage response to double-stranded DNA breaks (DSBs). Using affinity purification coupled to mass spectrometry, we identified the nucleosome remodeling and deacetylation (NuRD) complex as the top interactor of BMRF1. We further found that NuRD components localize with BMRF1 at viral replication compartments and that this interaction occurs through the BMRF1 C-terminal region previously shown to mediate transcriptional activation. We identified an RBBP4 binding motif within this region that can interact with both RBBP4 and MTA2 components of the NuRD complex and showed that point mutation of this motif abrogates NuRD binding as well as the ability of BMRF1 to activate transcription from the BDLF3 and BLLF1 EBV promoters. In addition to its role in transcriptional regulation, NuRD has been shown to contribute to DSB signaling in enabling recruitment of RNF168 ubiquitin ligase and subsequent ubiquitylation at the break. We showed that BMRF1 inhibited RNF168 recruitment and ubiquitylation at DSBs and that this inhibition was at least partly relieved by loss of the NuRD interaction. The results reveal a mechanism by which BMRF1 activates transcription and inhibits DSB signaling and a novel role for NuRD in transcriptional activation in EBV.IMPORTANCE The Epstein-Barr virus (EBV) BMRF1 protein is critical for EBV infection, playing key roles in viral genome replication, activation of EBV genes, and inhibition of host DNA damage responses (DDRs). Here we show that BMRF1 targets the cellular nucleosome remodeling and deacetylation (NuRD) complex, using a motif in the BMRF1 transcriptional activation sequence. Mutation of this motif disrupts the ability of BMRF1 to activate transcription and interfere with DDRs, showing the importance of the NuRD interaction for BMRF1 functions. BMRF1 was shown to act at the same step in the DDR as NuRD, suggesting that it interferes with NuRD function.


Subject(s)
Antigens, Viral/metabolism , DNA Damage , Herpesvirus 4, Human/metabolism , Mi-2 Nucleosome Remodeling and Deacetylase Complex/metabolism , Antigens, Viral/genetics , Cell Line, Tumor , DNA Replication , DNA, Viral/genetics , DNA-Binding Proteins/metabolism , Epstein-Barr Virus Infections/virology , HEK293 Cells , HeLa Cells , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/physiology , Humans , Membrane Glycoproteins/metabolism , Promoter Regions, Genetic , Signal Transduction , Trans-Activators/metabolism , Transcriptional Activation , Viral Proteins/metabolism , Virus Replication
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