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.

Droplet digital polymerase chain reaction assay for methylated ring finger protein 180 in gastric cancer

BACKGROUND Gastric cancer(GC)is one of the most prevalent malignant tumors that endangers human health.Early diagnosis is essential for improving the prognosis and survival rate of GC patients.Ring finger protein 180(RNF180)is involved in the regulation of cell differentiation,proliferation,apoptosis,and tumorigenesis,and aberrant hypermethylation of CpG islands in the promoter is strongly associated with the occurrence and development of GC.Thus,methylated RNF180 can be used as a potential biomarker for GC diagnosis.AIM To use droplet digital polymerase chain reaction(ddPCR)to quantify the methylation level of the RN180 gene.A reproducible ddPCR assay to detect methylated RNF180 from trace DNA was designed and optimized.METHODS The primer and probe were designed and selected,the conversion time of bisulfite was optimized,the ddPCR system was adjusted by primer concentration,amplification temperature and amplification cycles,and the detection limit of ddPCR was determined.RESULTS The best conversion time for blood DNA was 2 h 10 min,and that for plasma DNA was 2 h 10 min and 2 h 30 min.The results of ddPCR were better when the amplification temperature was 56°C and the number of amplification cycles was 50.Primer concentrations showed little effect on the assay outcome.Therefore,the primer concentration could be adjusted according to the reaction system and DNA input.The assay required at least 0.1 ng of input DNA.CONCLUSION In summary,a ddPCR assay was established to detect methylated RNF180,which is expected to be a new diagnostic biomarker for GC.

Role of Ring Finger Protein 213 in Moyamoya Disease

Objective：The aim of this study was to help people comprehensively understand the research advances related to ring finger protein 213 （RNF213） in moyamoya disease （MMD） and to understand the disease at the molecular level to provide a new perspective of the diagnosis of the disease.Data Sources：This review was based on data in articles published between 2005 and 2015 that were retrieved from the PubMed database.The search terms included RNF213,MMD,intracranial major artery stenosis/occlusion （ICASO）,genotype,phenotype,mutant and variants,and the combinations of these terms.Study Selection：Articles related to MMD and RNF213 were selected for review,and we also reviewed publications related to ICASO.Results：RNF213 is not only associated with MMD but also associated with intracranial major artery stenosis.In addition,RNF213 variants exhibit apparent ethnic diversity;specifically,the c.14576G〉A variant is mainly detected in Korean,Chinese,and Japanese populations,particularly the latter population.The genotypes of RNF213 correlate with the phenotypes of MMD;for example,the homozygous c.14576G〉A variant is associated with early-onset,severe symptoms,and an unfavorable prognosis.Furthermore,the RNF213 c.14576G〉A variant should be considered during the diagnosis of MMD because no patients with quasi-MMD have been reported to carry the RNF213 c.14576G〉A variant whereas 66 of 78 patients with definite MMD have been found to carry this variant.Conclusions：The growing literature demonstrates that MMD is primarily caused by the synergy of genetic and environmental factors,and unknown genetic modifiers might play roles in the etiology of MMD.Further research should be conducted to clarify the pathogenic mechanism of MMD.

The RING Finger Protein Nt RCP1 Is Involved in the Floral Transition in Tobacco(Nicotiana tabacum)

The transition from the vegetative phase to the reproductive phase is a major developmental process in flowering plants.The underlying mechanism controlling this cellular process remains a research focus in the field of plant molecular biology.In the present work,we identified a gene encoding the C3H2C3-type RING finger protein Nt RCP1 from tobacco BY-2 cells.Enzymatic analysis demonstrated that Nt RCP1 is a functional E3 ubiquitin ligase.In tobacco plants,expression level of Nt RCP1 was higher in the reproductive shoot apices than in the vegetative ones.Nt RCP1-overexpressing plants underwent a more rapid transition from the vegetative to the reproductive phase and flowered markedly earlier than the wild-type control.Histological analysis revealed that the shoot apical meristem of Nt RCP1-overexpressing plants initiated inflorescence primordia precociously compared to the wild-type plant due to accelerated cell division.Overexpression of Nt RCP1 in BY-2 suspension cells promoted cell division,which was a consequence of the shortened G2 phase in the cell cycle.Together,our data suggest that Nt RCP1 may act as a regulator of the phase transition,possibly through its role in cell cycle regulation,during vegetative/reproductive development in tobacco plant.

RNF26 up-regulates PD-L1 to regulate the cancer immune response in ccRCC

Background:Clear cell renal cell carcinoma(ccRCC)stands as the most prevalent form of kidney cancer,accounting for a significant proportion of malignancies affecting the kidneys.ccRCC is well known as a type of tumour with immunogenicity.Immune checkpoint inhibitors(ICIs)aim to enhance the anticancer immune response in ccRCC by blocking programmed cell death 1 ligand 1/programmed death 1(PD-L1/PD-1)pathways.In a previous study,we showed that RING finger protein 26(RNF26)degrades chromobox 7(CBX7)to activate the tumor necrosis factor(TNF)in ccRCC.Methods:We analyzed The Cancer Genome Atlas(TCGA)database using the R package ESTIMATE and found that RNF26 was significantly associated with ccRCC immune infiltration.The relationship between RNF26 and the PD1 checkpoint signaling pathway was detected by enrichment analysis.In addition,the molecular mechanism of RNF26 up-regulation of PD-L1 was detected by transcriptome sequencing,RT-qPCR,and Western Blot in ccRCC cell lineages 786-O and A498 cells.The transplantation tumor experiments in C57BL/6 mice were used to test the efficacy of anti-PD1 and knockdown of RNF26 in vivo.Results:We showed that RNF26 suppressed the immune response to ccRCC.Next,we revealed that RNF26 activated the PD-1 checkpoint pathway to suppress the immune response to ccRCC,possibly via the CBX7/PD-L1 axis.Conclusion:The suggestion derived from our results is that targeting RNF26 holds the potential to amplify the efficacy of anticancer immunotherapies in the treatment of ccRCC.

The role of roof plate-specific spondins in liver homeostasis and disease

As evolutionarily conserved signals,roof plate-specific spondins(R-spondins;RSPOs)are a family with four members(RSPO1e4)exerting distinctly different functions.RSPOs have five receptors and correlate with different signaling pathways through these receptors and then perform various functions.Moreover,their best-known molecular function is the capacity to enhance WNT signaling pathways,which play critical roles in several processes.A recent study shows that RSPOs not only potentiate the WNT/beta(b)-catenin signaling pathway but are also involved in the WNT/planar cell polarity signaling pathway.RSPOs influence liver homeostasis and the development of multiple liver diseases.RSPO1 increases cell proliferation,protects hepatocytes from injury,improves liver regenerative potential,and affects liver metabolic zonation.RSPO2 not only regulates proliferation-associated genes and promotes differentiation in the liver but also participates in liver fibrosis through the WNT/b-catenin signaling pathway.RSPO3 is a key determinant of proper liver function,such as promoting hepatocyte regeneration and maintaining liver zonation.RSPO3 is upregulated in liver fibrosis and livers of patients with nonalcoholic steatohepatitis.Besides,RSPO2 and RSPO3 are confirmed as oncogenes and involved in the occurrence of liver cancer.The role of RSPO4 in the liver remains unclear.In this review,the structural and biochemical properties of RSPOs and their receptors and their roles in liver homeostasis and disease are summarized.