Genetic investigation of the ubiquitin-protein ligase E3A gene as putative target in Angelman syndrome

BACKGROUND Angelman syndrome(AS)is caused by maternal chromosomal deletions,imprinting defects,paternal uniparental disomy involving chromosome 15 and the ubiquitin-protein ligase UBE3A gene mutations.However the genetic basis remains unclear for several patients.AIM To investigate the involvement of UBE3A gene in AS and identifying new potential genes using exome sequencing.METHODS We established a cohort study in 50 patients referred to Farhat Hached University Hospital between 2006 and 2021,with a strong suspicion of AS and absence of chromosomal aberrations.The UBE3A gene was screened for mutation detection.Two unrelated patients issued from consanguineous families were subjected to exome analysis.RESULTS We describe seven UBE3A variants among them 3 none previously described including intronic variants c.2220+14T>C(intron14),c.2507+43T>A(Exon15)and insertion in Exon7:c.30-47_30-46.The exome sequencing revealed 22 potential genes that could be involved in AS-like syndromes that should be investigated further.CONCLUSION Screening for UBE3A mutations in AS patients has been proven to be useful to confirm the diagnosis.Our exome findings could rise to new potential alternative target genes for genetic counseling.

Research Progress in Function and Regulation of E3 Ubiquitin Ligase SMURF1

Smad ubiquitylation regulatory factor 1(Smurf1)is an important homologous member of E6-AP C-terminus type E3 ubiquitin ligase.Initially,Smurf1 was reportedly involved in the negative regulation of the bone morphogenesis protein(BMP)pathway.After further research,several studies have confirmed that Smurf1 is widely involved in various biological processes,such as bone homeostasis regulation,cell migration,apoptosis,and planar cell polarity.At the same time,recent studies have provided a deeper understanding of the regulatory mechanisms of Smurf1’s expression,activity,and substrate selectivity.In our review,a brief summary of recent important biological functions and regulatory mechanisms of E3 ubiquitin ligase Smurf1 is proposed.

抑制Ligase4或Xrcc6活性增强斑马鱼原始生殖细胞中DNA同源重组的效率(英文)

利用斑马鱼作为体内模型,研究旨在提高斑马鱼原始生殖细胞(Primordial germ cells,PGCs)中同源重组(Homologous recombination,HR)的效率。首先,将UAS:m RFP-nos1载体显微注射到Tg(kop:Kal TA4)转基因胚胎中标记转基因PGCs,结果表明筛选PGCs特异表达m RFP的胚胎能够相对提高转基因的生殖系传递效率。随后建立了PGCs中HR效率的评估体系,并且证明抑制DNA ligase IV(Lig4)和Xrcc6(曾用名Ku70)的活性不但在全胚胎水平,而且在PGCs水平都能够显著提高HR的效率。研究表明Tg(kop:Kal TA4)转基因品系是开展HR介导的基因打靶的一个有效平台。

沉默Ku70促进PARP1、ligase3和XRCC1在DNA双链断裂染色质聚集

目的研究碱基切除修复途径(base excision repair,BER)关键因子PARP1、ligase3和XRCC1在Ku70缺失的条件下与DNA双链断裂(double-strand break,DSB)所在染色质的结合及抑制PARP1所产生的影响。方法采用可经药物诱导Ku70 shRNA的细胞株,以高效的DNA双链断裂诱导剂刺孢霉素calicheamicin诱导DSB。分离不同组分蛋白联合稳定同位素标记定量差异蛋白组分析法鉴定Ku70下调后在损伤染色质聚集增多的蛋白,Western blot进行验证并检测PARP1抑制剂DIQ对其染色质聚集的影响。结果在药物Doxy作用下,Ku70明显下调,其余蛋白的表达不受影响。稳定同位素标记定量蛋白组学方法鉴定出PARP1、ligase3和XRCC1在Ku70下调后在损伤染色质聚集增多。Western blot进行了验证并显示PARP1、ligase3和XRCC1在损伤染色质的聚集随DSB程度增加而增加。施加PARP1抑制剂DIQ,随着DIQ浓度的上升,ligase3在损伤染色质的聚集逐渐减少。结论沉默Ku70后,PARP1、ligase3和XRCC1在DSB染色质聚集增加,这种聚集与DSB程度变化一致,并且ligase3的染色质聚集具有一定程度的PARP1依赖性。

分子对接、CRISPR/Cas9技术筛选并验证DNA ligase Ⅳ抑制剂

为了筛选靶向DNA连接酶Ⅳ的抑制剂以实现更有效的基因定点插入,采用分子对接技术筛选出与前期研究中靶向DNA连接酶Ⅳ的抑制剂SCR7作用类似的小分子化合物。筛选到与化合物库一致的nocodazole、Fisetin和Methylene blue 3个小分子化合物,通过用MSTN基因T11位点序列截断的Firefly Luciferase荧光素酶报告载体结合CRISPR/Cas9-gRNA-T11载体共转细胞,并结合不同的小分子化合物处理。结果表明,没有用小分子化合物处理时,萤火虫荧光素酶被截断的位置发生NHEJ修复,不能得到大量有活性的萤火虫荧光素酶;经过小分子化合物处理,抑制了细胞内的NHEJ,提高了HDR效率,能得到大量有活性的萤火虫荧光素酶。使用nocodazole、Methylene blue和Fisetin处理后的萤火虫荧光素酶检测结果65256.3、53713和77058.3分别是SCR7处理后的萤火虫荧光素酶检测结果41905.3的1.6、1.3和1.8倍,是没有SCR7处理后的萤火虫荧光素酶检测结果10120的6.4、5.3和7.6倍。证明所用的筛选策略正确,所筛选出的小分子化合物是具有DNA ligaseⅣ抑制活性的抑制剂,为后续研究奠定了基础。

Role of E3 ubiquitin ligases in gastric cancer

E3 ubiquitin ligases have an important role in carcinogenesis and include a large family of proteins that catalyze the ubiquitination of many protein substrates for targeted degradation by the 26S proteasome.So far,E3 ubiquitin ligases have been reported to have a role in a variety of biological processes including cell cycle regulation,cell proliferation,and apoptosis.Recently,several kinds of E3 ubiquitin ligases were demonstrated to be generally highly expressed in gastric cancer(GC) tissues and to contribute to carcinogenesis.In this review,we summarize thecurrent knowledge and information about the clinical significance of E3 ubiquitin ligases in GC.Bortezomib,a proteasome inhibitor,encouraged the evaluation of other components of the ubiquitin proteasome system for pharmaceutical intervention.The clinical value of novel treatment strategies targeting aberrant E3 ubiquitin ligases for GC are discussed in the review.

Molecular cloning and functional characterization of apple U-box E3 ubiquitin ligase gene MdPUB29 reveals its involvement in salt tolerance

An E3 ubiquitin ligase gene(Genbank accession no.:MD01 G1010900) was cloned from the Royal Gala apple genome(Malus×domestica Borkh.).Sequence analysis showed that the length of the MdPUB29 gene was 1 275 bp,encoding 424 amino acids.Phylogenetic tree analysis indicated that the apple E3 ubiquitin ligase exhibited the greatest sequence similarity to Pyrus×bretschneideri.The predicted protein structural domain of MdPUB29 showed that it contained a U-box domain.qRT-PCR analysis showed that Md PUB29 was expressed widely in different tissues of the Royal Gala apple species,and was highly expressed in the root,while the expression of MdPUB29 was significantly inhibited by exogenous NaCl.Immunoblotting assays revealed that MdPUB29 protein abundance in tissue cultures of the Royal Gala apple accumulated under NaC l stress conditions.Three-dimensional protein structure prediction indicated that MdPUB29 was highly homologous with AtPUB29.The growing potential of MdPUB29-expressing apple calli and Arabidopsis were much stronger than that of the control under salt stress conditions,suggesting that MdPUB29 may positively regulate salt tolerance.

Human RING finger protein ZNF645 is a novel testis-specific E3 ubiquitin ligase

A large number of testis-specific genes are involved in the complex process of mammalian spermatogenesis. Identification of these genes and their roles is important for understanding the mechanisms underlying spermatogenesis. Here we report on a novel human RING finger protein, ZNF645, which contains a C3HC4 RING finger domain, a C2H2 zinc-finger domain, and a proline-rich region, indicating that it has a structure similar to that of the c-Cbl-like protein Hakai. ZNF645 was exclusively expressed in normal human testicular tissue. Immunohistochemical analysis confirmed that ZNF645 protein was present in spermatocytes, round and elongated spermatids, and Leydig cells. Immunofluorescence staining of mature sperms further showed that the ZNF645 protein was localized over the postacrosomal perinuclear theca region and the entire length of sperm tail. An in vitro ubiquitination assay indicated that the RING finger domain of the ZNF645 protein had E3 ubiquitin ligase activity. Therefore, we suggest that ZNF645 might act as an E3 ubiquitin-protein ligase and play a role in human sperm production and quality control.

Role of E3 ubiquitin ligases in lung cancer

E3 ubiquitin ligases are a large family of proteins that catalyze the ubiquitination of many protein substrates for targeted degradation by the 26S proteasome.Therefore,E3 ubiquitin ligases play an essential role in a variety of biological processes including cell cycle regulation,proliferation and apoptosis.E3 ubiquitin ligases are often found overexpressed in human cancers,including lung cancer,and their deregulation has been shown to contribute to cancer development.However,the lack of specific inhibitors in clinical trials is a major issue in targeting E3 ubiquitin ligases with currently only one E3 ubiquitin ligase inhibitor being tested in the clinical setting.In this review,we focus on E3 ubiquitin ligases that have been found deregulated in lung cancer.Furthermore,we discuss the processes in which they are involved and evaluate them as potential anti-cancer targets.By better understanding the mechanisms by which E3 ubiquitin ligases regulate biological processes and their exact role in carcinogenesis,we can improve the development of specific E3 ubiquitin ligase inhibitors and pave the way for novel treatment strategies for cancer patients.

Ovarian cancer and DNA repair: DNA ligase IV as a potential key

Ovarian cancer(OC)is the sixth most common cancer and the seventh cause of death from cancer in women.The etiology and the ovarian carcinogenesis still need clarification although ovulation may be determinant due to its carcinogenic role in ovarian surface epithelium.The link between ovarian carcinogenesis and DNA repair is well established and it became clear that alterations in DNA damage response may affect the risk to develop OC.Polymorphisms are variations in the DNA sequence that exist in normal individuals of a population and are capable to change,among other mechanisms,the balance between DNA damage and cellular response.Consequently,genetic variability of the host has a great role in the development,progression and consequent prognosis of the oncologic patient as well as in treatment response.Standard treatment for OC patients is based on cytoreductive surgery,followed by chemotherapy with a platinum agent and a taxane.Although 80%of the patients respond to the first-line therapy,the development of resistance is common although the mechanisms underlying therapy failure remain mostly unknown.Because of their role in oncology,enzymes involved in the DNA repair pathways,like DNA Ligase IV(LIG4),became attractive study targets.It has been reported that variations in LIG4 activity can lead to a hyper-sensitivity to DNA damage,deregulation of repair and apoptosis mechanisms,affecting the susceptibility to cancer development and therapy response.To overcome resistance mechanisms,several investigations have been made and the strategy to target crucial molecular pathways,such as DNA repair,became one of the important areas in clinical oncology.This review aims to elucidate the link between DNA repair and OC,namely which concerns the role of LIG4 enzyme,and how genetic polymorphisms in LIG4 gene can modulate the activity of the enzyme and affect the ovarian carcinogenesis and treatment response.Moreover,we try to understand how LIG4 inhibition can be a potential contributor for the development of new cancer treatment strategies.

Genome-wide identification and expression analysis of Gossypium RING-H2 finger E3 ligase genes revealed their roles in fiber development,and phytohormone and abiotic stress responses

Background： RING H2 finger E3 ligase （RH2FE3） genes encode cysteine rich proteins that mediate E3 ubiquitin ligase activity and degrade target substrates. The roles of these genes in plant responses to phytohormones and abiotic stresses are well documented in various species, but their roles in cotton fiber development are poorly understood. To date, genome wide identification and expression analyses of Gossypium hirsutum RH2FE3 genes have not been reported. Methods： We performed computational identification, structural and phylogenetic analyses, chromosomal distribution analysis and estimated KJKs values of G hirsutum RH2FE3 genes. Orthologous and paralogous gene pairs were identified by all versus all BLASTP searches. We predicted cis regulatory elements and analyzed microarray data sets to generate heatmaps at different development stages. Tissue specific expression in cotton fiber, and hormonal and abiotic stress responses were determined by quantitative real time polymerase chain reaction （qRT PCR） analysis. Results： We investigated 140 G hirsutum, 80 G. orboreum, and evolutionary mechanisms and compared them with orthologs 89 G. roimondii putative RH2FB genes and their in Arobidopsis and rice. A domain based analysis of the G hirsutum RH2FE3 genes predicted conserved signature motifs and gene structures. Chromosomal localization showed the genes were distributed across all G hirsutum chromosomes, and 60 duplication events （4 tandem and 56 segmental duplications） and 98 orthologs were detected, cis elements were detected in the promoter regions of G hirsutum RH2FE3 genes. Microarray data and qRT PCR analyses showed that G hirsutum RH2FE3 genes were strongly correlated with cotton fiber development. Additionally, almost all the （brassinolide, gibberellic acid （GA）, indole 3-acetic acid drought, and salt）. dentified genes were up regulated in response to phytohormones （IAA）, and salicylic acid （SA）） and abiotic stresses （cold, heat, Conclusions： The genome wide identification, comprehensive analysis, and characterization of conserved domains and gene structures, as well as phylogenetic analysis, cis element prediction, and expression profile analysis of G hirsutum RH2FE3 genes and their roles in cotton fiber development and responses to plant hormones and abiotic stresses are reported here for the first time. Our findings will contribute to the genome wide analysis of putative RH2FE3 genes in other species and lay a foundation for future physiological and functional research on G hirsutum RH2FE3 genes.

RNF13： a novel RING-type ubiquitin ligase over-expressed in pancreatic cancer

由 E3 ubiquitin ligases 的蛋白质 ubiquitination 在癌症开发起一个重要作用。在这研究，我们提供 RING-finger-containing 蛋白质 RNF13 是 ER/Golgi 联系膜的 E3 ubiquitin ligase，它的戒指手指领域为 ubiquitin ligase 活动被要求的试验性的证据。胰腺的 ductal 腺癌(PDAC ) 和从 72 个病人的 paracancerous 正常纸巾的 Immunohistochemical 分析在 30 件肿瘤样品记录了 RNF13 在表示上(41.7% ， 30/72 ) ，并且它的表示显著地与组织学的分级被联系(P = 0.024 ) 。另外， RNF13 在癌症前期的损害被检测：在长期的胰腺炎(CP ) 和胰腺的 intraepithelial 瘤形成(PanIN ) 的管状的建筑群(79.3% ， 23/29 并且 62.8% ， 22/35，分别地) 。而且，染色的 RNF13 显著地与 Tenascin-C 表示被相关(P = 0.004 ) 在 PDAC 样品，进一步在癌症支持 RNF13 的角色前进。在胰腺的 MiaPaca-2 癌症房间的野类型然而并非戒指域异种 RNF13 的在表示上由矩阵 metalloproteinase-9 增加了侵略潜力和 gelatinolytic 活动。一起拿，这些调查结果表明 RNF13 是涉及胰腺的 carcinogenesis 的新奇 E3 ubiquitin ligase；由 RNF13 的蛋白质的调停 ubiquitin 的修正可以参予胰腺的癌症开发。

Effects of Nephrolithiasis on Serum DNase(Deoxyribonuclease Ⅰ and Ⅱ) Activity and E3 SUMO-Protein Ligase NSE2(NSMCE2) in Malaysian Individuals

Objective Nephrolithiasis is one of the most common disorders of the urinary tract. The aim of this study was to examine a possible relationship between DNase Ⅰ/Ⅱ activity and E3 SUMO-protein ligase NSE2 in the sera of nephrolithiasis patients to evaluate the possibility of a new biomarker for evaluating kidney damage. Methods Sixty nephrolithiasis patients and 50 control patients were enrolled in a case-control study. Their blood urea, creatinine, protein levels and DNase Ⅰ/Ⅱ activity levels were measured by spectrometry. Serum NSMCE2 levels were measured by ELISA. Blood was collected from patients of the government health clinics in Kuantan-Pahang and fulfilled the inclusion criteria. Results The result indicated that mean levels of sera NSMCE2 have a significantly increase（P〈0.01） in patients compared to control group. Compared with control subjects, activities and specific activities of serum DNase Ⅰ and Ⅱ were significantly elevated in nephrolithiasis patients（P〈0.01）. Conclusion This study suggests that an increase in serum concentrations of DNase Ⅰ/Ⅱ and E3 SUMO-protein ligase NSE2 level can be used as indicators for the diagnosis of kidney injury in patients with nephrolithiasis.

TaGW2L,a GW2-like RING finger E3 ligase,positively regulates heading date in common wheat(Triticum aestivum L.)

RING finger E3 ligases play an important role in regulating plant growth and development by mediating substrate degradation.In this study,we identified TaGW2L,encoding a Grain width and weight2(GW2)-like RING finger E3 ligase,as a novel positive regulator of heading date in wheat(Triticum aestivum L.).TaGW2L exhibited high amino acid sequence similarities with TaGW2 homoeologs,particularly in the conserved RING finger domain.Expression analysis indicated that TaGW2L was constitutively expressed in various wheat tissues.TaGW2L showed transactivation activity in yeast and could interact with the ubiquitin-conjugating enzymes E2_(s).An in vitro ubiquitination assay verified that TaGW2L possessed a similar E3 ligase activity to TaGW2.Overexpression of the TaGW2L-7A homoeolog in wheat led to a significantly earlier heading date under both natural conditions and long-day conditions.Transcriptome analysis revealed that multiple known genes positively regulating wheat heading were significantly upregulated in the TaGW2L-7A-overexpression plants compared with the wild-type control.Together,our findings shed light on the role of TaGW2L in wheat heading date and provide potential applications of TaGW2L for the adaptation improvement of crops.

Comparison of ligase detection reaction and real-time PCR for detection of low abundant YMDD mutants in patients with chronic hepatitis B

AIM: To compare the ligase detection reaction (LDR) and real-time PCR for detection of low abundant YMDD mutants in patients with chronic hepatitis B infection.METHODS: Mixtures of plasmids and serum samples from 52 chronic hepatitis B patients with low abundant lamivudine-resistant mutations were tested with LDR and real-time PCR. Time required and reagent cost for both assays were evaluated.RESULTS: Real-time PCR detected 100, 50, 10, 1 and 0.1% of YIDD plasmid, whereas LDR detected 100, 50, 10, 1, 0.1, and 0.01% of YIDD plasmid, in mixtures with YMDD plasmid of 106 copies/mL. Among the 52 clinical serum samples, completely concordant results were obtained for all samples by both assays, and 39 YIDD, 9 YVDD, and 4 YIDD/YVDD were detected. Cost and time required for LDR and real-time PCR are 60/80 CNY (8/10.7 US dollars) and 4.5/2.5 h, respectively.CONCLUSION: LDR and real-time PCR are both sensitive and inexpensive methods for monitoring low abundant YMDD mutants during lamivudine therapy in patients with chronic hepatitis B. LDR is more sensitive and less expensive, while real-time PCR is more rapid.

Study the effect of kidney stones on serum xanthine oxidase, ecto-5'-nucleotidase activity and E3 SUMO-protein ligase NSE2(NSMCE2) in Malaysian individuals

Objective: To verify possible relations between 5'-nucleotidase, xanthine oxidase to E3 small ubiquitin-like modifier-protein ligase non structural maintenance of chromosomes elements 2 in sera patients with kidney stones and to evaluate the possibility of a new biomarker for the evaluation of kidney damage. Methods: A sixty patients with known kidney stones who appeared the government health clinics in Kuantan–Pahang and fifty apparently healthy were taken as control group. The 5'-nucleotidase,xanthine oxidase and other biochemical parameters were measured by colorimetric tests. The serum NSMCE2 were measured by enzyme linked immunosorbent assay.Results: The mean serum xanthine oxidase [(39.98±19.70) IU/L] and ecto-5'-nucleotidase activity(40.03±9.53 IU/L) were significantly higher than the controls' levels of(18.04 ±6.26) and(16.06 ±4.61) IU/L respectively. There were 85.00% and 83.33%, of patients with kidney stones who had abnormal ecto-5'-nucleotidase activity and uric acid respectively while xanthine oxidase activity was less sensitive 58.33%.Conclusions: The present study suggests that the increase in serum of xanthine oxidase,ecto-5'-nucleotidase activities E3 small ubiquitin-like modifier-protein ligase NSE2 concentration can be used as biomarkers for diagnosis of kidney damage in patients with kidney stone,also in developments of change DNA damage and inflammation disorders in these patients.

Flexibility in the order of action and in the enzymology of the nuclease, polymerases, and ligase of vertebrate non-homologous DNA end joining： relevance to cancer, aging, and the immune system

加入的 Nonhomologous 脱氧核糖核酸结束(NHEJ ) 是为在人的房间并且在多细胞的优核质的双海滨脱氧核糖核酸裂缝的修理的主要小径。双海滨裂缝的原因经常碎裂在损坏的地点的脱氧核糖核酸，导致在那里的信息的损失。NHEJ 不恢复失去的信息并且可以将切除另外的核苷酸在修理过程期间。修理大量 overhang 并且损坏配置的能力反映 NHEJ 的核酸酶，聚合酶，和连接酶的灵活性。单个部件的灵活性也解释 NHEJ 能在修理脱氧核糖核酸结束的任何给定的对的方法的大数字。局部地，在 NHEJ 的地点，修理可以贡献癌症和老化的信息的损失，而是由 NHEJ 的行动保证染色体的全部片断没被失去。

Serum E3 SUMO-protein ligase NSE2 level and peroxynitrite related to oxidative stress in nephrolithiasis patients

Objective: To prove probable relations between serum E3 SUMO-protein ligase NSE2(NSMCE2) concentration, peroxynitrite related to oxidative stress in nephrolithiasis patients.Methods: A total of 60 patients with nephrolithiasis and 50 healthy volunteers were involved in this study. Colorimetric method was used to detect blood urea, creatinine, uric acid, protein, albumin, total antioxidant status, total oxidant status, peroxynitrite, nitric oxide and oxidative stress index. Glutathione, NSMCE2 and superoxide dismutase were measured by ELISA.Results: A significant increase in level of peroxynitrite, total oxidant status, NSMCE2 and oxidative stress index in patients was observed, while total antioxidant status and glutathione were significantly decreased.Conclusions: The study concluded that serum NSMCE2 significantly correlated with peroxynitrite and oxidative stress in patients with nephrolithiasis.

High-level expression of 4-coumarate:coenzyme A ligase gene Pt4CL1 of Populus tomentosa in E. coli

In order to investigate the enzymatic properties of the 4CL1 of Populus tomentosa, the recombinant expression vector pQE31-4CL 1 was constructed. The recombinant was identified by three restriction endonucleases, then the vector pQE31-4CL 1 was transformed into expression host M15 （pREP4） and induced by isopropyl-a-D-thiogalactoside （IPTG） to express 60 kD fused protein Pt4CL1. The biologically active Pt4CL1, expressed as soluble protein, was achieved with 0.6 mmol＇L-1 IPTG induction as the expression temperature declined from 37 to 28℃. The 6-His tag facilitates affinity binding to Ni^2＋-nitrolotriacetic acid （NTA） and enables one-step purification to acquire the molecular SDS-PAGE electrophoresis purity of the active 4CL1 protein by agarose coupled with Ni^2＋-NTA affinity chromatography. The optimal substrate for Pt4CL 1 was 4-coumarate.