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.

Correlation of endolymphatic hydrops and perilymphatic enhancement with the clinical features of Ménière's disease.

OBJECTIVES: To use three-dimensional real inversion recovery (3D-real IR) MRI to investigate correlations between endolymphatic hydrops (EH) grades or the degree of perilymphatic enhancement (PE) and clinical features of Ménière's disease (MD), as previous findings have been inconsistent. METHODS: A total of 273 consecutive patients with definite unilateral MD were retrospectively enrolled from September 2020 to October 2021. All patients underwent 3D-real IR and 3D-T2WI 6 h after intravenous gadolinium injection. MD-related symptom duration and vertigo frequency were recorded. EH grades were evaluated, the signal intensity ratio (SIR) was measured, and correlations between clinical features and EH, PE were assessed respectively. RESULTS: The study included 123 males and 150 females, with a mean age of 53.0 years. A longer duration of vertigo was associated with higher cochlear EH grades, whereas the opposite was true for the duration of aural fullness. A longer time since vertigo onset was associated with higher vestibular EH grades; the opposite was true for the duration of individual vertigo attacks. The multiple regression analysis revealed that age, tinnitus duration, and vestibular EH were risk factors for SIR. Furthermore, the low-frequency hearing threshold (HT) was a risk factor for cochlear and vestibular EH, and the SIR. CONCLUSION: The EH grade and SIR (an indicator for the quantitative evaluation of PE) were correlated with clinical features and HT of MD; thus, imaging can be a valuable tool in planning individualised treatment. CLINICAL RELEVANCE STATEMENT: This study revealed that the grade of endolymphatic hydrops and degree of perilymphatic enhancement positively correlates with the length of time since onset of clinical symptoms and hearing thresholds in patients with Ménière's disease, facilitating the tailored treatment. KEY POINTS: • Relationships between 3-dimensional real inversion recovery features and clinical symptoms in Ménière's disease are unknown. • Symptom duration and hearing thresholds correlated with endolymphatic hydrops grades and degree of perilymphatic enhancement. • MRI features correlate with MD severity; thus, imaging is valuable for planning tailored treatment.

Predictive value of systemic immune-inflammation index combined with N-terminal pro-brain natriuretic peptide for contrast-induced acute kidney injury in patients with STEMI after primary PCI.

OBJECTIVE: To investigate the relationship between the incidence of contrast-induced acute kidney injury (CI-AKI) after emergency percutaneous coronary intervention (PCI) and preoperative systemic immune-inflammation index (SII) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in patients with acute ST-segment elevation myocardial infarction (STEMI), and to further analyze the predictive value of the combination of SII and NT-proBNP for CI-AKI. METHODS: The clinical data of 1543 patients with STEMI who underwent emergency PCI in our hospital from February 2019 to December 2022 were retrospectively analyzed. All patients were divided into training cohort (n = 1085) and validation cohort (n = 287) according to chronological order. The training cohort was divided into CI-AKI (n = 95) and non-CI-AKI (n = 990) groups according to the 2018 European Society of Urogenital Radiology definition of CI-AKI. Multivariate Logistic regression analysis was used to determine the independent risk factors for CI-AKI. Restricted cubic spline (RCS) was used to explore the relationship between SII, NT-proBNP, and the risk of CI-AKI. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of SII, NT-proBNP, and their combination in CI-AKI. RESULTS: The incidence of CI-AKI was 8.8% (95/1085). Multivariate logistic regression analysis showed that SII, NT-proBNP, age, baseline creatinine, fasting blood glucose, and diuretics were independent risk factors for CI-AKI. RCS analysis showed that SII > 1084.97 × 109/L and NT-proBNP > 296.12 pg/mL were positively associated with the incidence of CI-AKI. ROC curve analysis showed that the area under the curve of SII and NT-proBNP combined detection in predicting CI-AKI was 0.726 (95% CI 0.698-0.752, P < 0.001), the sensitivity was 60.0%, and the specificity was 77.7%, which were superior to the detection of SII or NT-proBNP alone. CONCLUSION: Preprocedural high SII and NT-proBNP are independent risk factors for CI-AKI after emergency PCI in patients with STEMI. The combined detection of SII and NT-proBNP can more accurately predict CI-AKI risk than the single detection.

MRI can help differentiate Ménière's disease from other menieriform diseases.

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

Prognostic Nutritional Index Combined with Triglyceride-Glucose Index to Contrast a Nomogram for Predicting Contrast-Induced Kidney Injury in Type 2 Diabetes Mellitus Patients with Acute Coronary Syndrome After Percutaneous Coronary Intervention.

Objective: Our objective was to develop and validate a nomogram model aiming at predicting the risk of contrast-induced acute kidney injury (CI-AKI) following percutaneous coronary intervention (PCI) in patients suffering from type 2 diabetes mellitus (T2DM) and also diagnosed with acute coronary syndrome (ACS). Methods: The study gathered data from 722 T2DM patients with ACS who received PCI treatment at the Affiliated Hospital of Xuzhou Medical University between February 2019 and December 2022, serving as the training set. Considering the validation set, the study included 217 patients who received PCI at the East Affiliated Hospital of Xuzhou Medical University. The patients were classified into CI-AKI and non-CI-AKI groups. The study employed univariate and multivariate logistic analysis for identifying independent risk factors for CI-AKI, followed by developing a predictive nomogram model for CI-AKI risk using R software. The predictive performance and clinical utility of the nomogram were assessed through internal and external validation, utilizing the areas under the receiver operating characteristic curve (AUC-ROC), the Hosmer-Lemeshow test and calibration correction curve, and decision curve analysis (DCA). Results: The nomogram comprised four variables: age, estimated glomerular filtration rate (eGFR), triglyceride-glucose (TyG) index, and prognostic nutritional index (PNI). The AUC-ROC were 0.785 (95% confidence interval (CI) 0.729-0.841) and 0.802 (95% CI 0.699-0.905) for the training and validation cohorts, respectively, indicating a high discriminative ability of the nomogram. The calibration assessment and decision curve analysis have substantiated the strong concordance and clinical usefulness of the aforementioned. Conclusion: The nomogram exhibits favorable discrimination and accuracy, enabling it to visually and individually identify pre-procedure high-risk patients, and possesses a predictive capacity regarding CI-AKI incidence after PCI in patients diagnosed with both T2DM and ACS.

Improving diagnostic accuracy for probable and definite Ménière's disease using magnetic resonance imaging.

PURPOSE: To determine whether magnetic resonance imaging (MRI) can improve diagnostic accuracy for definite and probable Ménière's disease (MD) based on perilymphatic enhancement (PE) and endolymphatic hydrops (EH). METHODS: 363 patients with unilateral MD (probable MD, n = 75 and definite MD, n = 288) were recruited. A three-dimensional zoomed imaging technique with parallel transmission SPACE real inversion recovery was performed 6 h after intravenous gadolinium injection to investigate the presence of PE and to evaluate the grading and location of EH. PE and EH characteristics were analyzed and compared between the probable and definite MD groups. RESULTS: The cochlear and vestibular EH grading on the affected side was more severe in the definite MD group than that in the probable MD group (P < 0.001). The EH locations within the inner ear on the affected side also differed between the two groups (χ2 = 81.15, P < 0.001). The signal intensity ratio (SIR) on the affected side was significantly higher in the definite MD group than in the probable MD group (t = 2.18, P < 0.05). The assessment of the combination of PE and EH parameters within the inner ear revealed a higher area under the curve (AUC) in the definite MD group (0.82) compared with the AUCs of the parameters assessed alone. CONCLUSION: The assessment of a combination of PE and EH parameters improved the diagnostic accuracy for probable and definite MD, suggesting that MRI findings may be clinically useful in the diagnosis of MD.

Konjac Glucomannan Aerogels Modified by Hydrophilic Isocyanate and Expandable Graphite with Excellent Hydrolysis Resistance, Mechanical Strength, and Flame Retardancy.

At present, biomass foamlike materials are a hot research topic, but they need to be improved urgently due to their defects such as large size shrinkage rate, poor mechanical strength, and easy hydrolysis. In this study, the novel konjac glucomannan (KGM) composite aerogels modified with hydrophilic isocyanate and expandable graphite were prepared by a facile vacuum freeze-drying method. Compared with the unmodified KGM aerogel, the volume shrinkage of the KGM composite aerogel (KPU-EG) decreased from 36.36 ± 2.47% to 8.64 ± 1.46%. Additionally, the compressive strength increased by 450%, and the secondary repeated compressive strength increased by 1476%. After soaking in water for 28 days, mass retention after hydrolysis of the KPU-EG aerogel increased from 51.26 ± 2.33% to more than 85%. The UL-94 vertical combustion test showed that the KPU-EG aerogel can achieve a V-0 rating, and the limiting oxygen index (LOI) value of the modified aerogel can reach up to 67.3 ± 1.5%. To sum up, the cross-linking modification of hydrophilic isocyanate can significantly improve the mechanical properties, flame retardancy, and hydrolysis resistance of KGM aerogels. We believe that this work can provide excellent hydrolytic resistance and mechanical properties and has broad application prospects in practical packaging, heat insulation, sewage treatment, and other aspects.

The clinical value of DCE-MRI for differentiating secondary laryngeal cartilage lesions.

To explore the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of laryngeal cartilage lesions. In this study, 3 groups of cases were selected, including 16 cases benign lesions of the laryngopharynx as the benign group, 17 cases malignant lesions of laryngopharynx as the malignant group and 23 healthy adults as the control group. Conventional magnetic resonance imaging and DCE-MRI were performed with a 3.0 T MR scanner. cutoff, sensitivity, specificity and area under the curve values were calculated via receiver operating characteristic curve analysis based on the pathologic findings of surgically resected specimens. There were significant differences in the values of the volume transfer constant (Ktrans), the rate constant between the extravascular extracellular space and blood plasma (Kep) and The extravascular extracellular space fractional volume (Ve) between the control, benign and malignant groups (P < .005). Among the 3 groups, the malignant group had the highest Ktrans and Ve values (0.8681 ±â€…0.3034 and 0.6186 ±â€…0.2405, respectively), and the benign group had the highest Kep value (2.445 ±â€…0.7346). The cutoff points of the Ktrans, Kep, and Ve values of the control, benign and malignant groups were 0.39, 1.261, and 0.195; 0.471, 0.964, and 0.235; and 0.706, 2.005, and 0.659, respectively. The Ktrans, Kep, and Ve values obtained via DCE-MRI may enable differentiating laryngeal cartilage lesions. DCE-MRI can be used to evaluate laryngeal cartilage lesions accurately and quantitatively.

Longitudinal variation of endolymphatic hydrops in patients with Ménière's disease.

Background: The relationships of endolymphatic hydrops (EH) and perilymphatic enhancement (PE) with Ménière's disease (MD) remains unclear. This study aimed to describe the dynamic variation of EH and PE for MD patients over 2 hospitalizations by applying magnetic resonance imaging (MRI) to further clarify the relationships of EH and PE with MD. Methods: A total of 77 MD patients who underwent inner ear MRI after intravenous administration of gadolinium and pure-tone average (PTA) testing during a first and second hospitalization were included. The degree of EH and PE were evaluated via MRI, and the duration and frequency of vertigo attacks and PTA were collected and recorded. The PTA, EH, and PE for the 2 hospitalizations were compared, and the relationships of EH and cochlear PE with the MD stage were investigated. Results: There was no difference between the 2 hospitalizations for duration of vertigo attacks or frequency of vertigo attacks. However, there were significant differences in PTA (Z=-3.02, P=0.003). Additionally, the cochlear and vestibular EH in the asymptomatic ear at the second hospitalization was significantly worse than that of the first hospitalization (Z=-2.33 and -2.49, P=0.020 and 0.013, respectively), while there were no differences in EH and PE in the affected ear (all P>0.05). Moreover, the degree of cochlear and vestibular EH was correlated with MD stage (both P<0.01). Conclusions: Although EH and PE in the affected ear were unchanged over 2 hospitalizations, an underlying EH in the asymptomatic ear and hearing loss in the affected ear for MD patients developed longitudinally with the duration of disease, and EH varied with the natural course of MD whereas PE did not. Therefore, EH instead of PE is necessary but insufficient to cause the clinical symptoms of MD.

Hepatic steatosis with mass effect: A case report.

BACKGROUND: Hepatic steatosis is a common radiologic finding. Some imaging inklings are the absence of a mass effect, and there is currently no report of hepatic steatosis with mass effect. CASE SUMMARY: A 23-year-old female was admitted due to a liver mass for half a month. No obvious abnormalities were found in physical and laboratory examinations. Ultrasound, computed tomography, and magnetic resonance imaging showed a huge mass between the liver and stomach with a significant mass effect, and the caudate lobe and left lobe of the liver were involved. The signal on T2- and T1- weighted fat-saturated images of the mass was significantly reduced, and the enhanced scan showed inhomogeneous enhancement. Surgical and pathological findings indicated the diagnosis of hepatic steatosis. The operation and re-review of the patient's images showed that the lesion was supplied by the branch of the hepatic artery. The signal on T1-weighted out-of-phase images of the lesion was lower than on in-phase images, and there was no black rim cancellation artifact around the hepatic steatosis area on T1-weighted out-of-phase images. The dynamic enhancement pattern of the lesion was similar to that of the adjacent normal liver parenchyma. The above characteristics suggested that the lesion was hepatic steatosis. However, in this case, the lesion showed exogenous growth and was mass-like, with an obvious mass effect, which has not been reported previously. CONCLUSION: Hepatic steatosis could grow exogenously and has an obvious mass effect. It needs to be distinguished from fat-rich tumors. The T1-weighted in- and out-of-phase images and dynamic enhanced scanning are valuable for differential diagnosis of this lesion.

A Rare Chordoma-The Epiglottic chordoma.

Chordomas are rare malignant bone tumors. Chordomas originate from notochordal elements. Chordomas have the phenotype of the embryonic notochord, characterized by the dual expression of cytokeratin and brachyury. Chordomas occur anywhere along the central axis. Rarely, chordomas occur in extra-axial structures. We could not find any reports on epiglottic chordoma. Here, we present a case of epiglottic chordoma to highlight this rare cause of laryngeal mass.

Imaging manifestations of juvenile hyaline fibromatosis: a case report and literature review.

Objective: Juvenile hyaline fibromatosis (JHF) is an autosomal recessive condition caused by a mutation in capillary morphogenesis gene 2 (CMG2) on chromosome 4q21. JHF is an extremely rare genetic disorder, and fewer than a hundred cases have been reported worldwide. In this case report, the clinical features, histopathological features and imaging manifestations of a case of JHF are presented. We present imaging manifestations of one case of JHF to deepen the radiologist's understanding of this condition. The histopathological feature of JHF is hyaline degeneration involving skeletal muscle. Therefore, the lesion has a slightly high density on CT imaging, iso- or hypointense signal on T 1WI and hypointense signal on T 2WI. The boundary between the lesion and skeletal muscle is unclear. Methods: An 8-year-old male (Case 1) was examined in our department with a complaint of multiple masses on the head, neck and back in 2021. The boy was the only child of his parents and was delivered at 40 weeks gestation by caesarean section. His parents were non-consanguineous. Results: JHF displays multiple slowly or rapidly growing subcutaneous nodules. The imaging manifestations can reflect histopathological components, including nodular connective tissue and amorphous, partially calcified hyaline material.

Unusual Appearance of Nasal Collagenous Fibroma (Desmoplastic Fibroblastoma) on Imaging.

Collagenous fibroma (CF) is a benign soft tissue tumour with good prognosis. Preoperative imaging diagnosis is essential to avoid unnecessarily extended resection, which may result in irreversible functional damage. However, few studies published to date have reported on the imaging features, associated with this condition. We, therefore, present a patient with histologically proven CF on the dorsum of nose, associated with an unusual appearance on magnetic resonance imaging. Low signal intensity on T2-weighted images and rim enhancement on gadolinium-DTPA (Gd-DTPA) enhanced images are reported in some previously reported cases. However, the unique point about this case is the markedly enhanced nodule revealed in the middle part of the lesion five hours after the administration of contrast media. To our knowledge, this is the first description of late gadolinium enhancement features associated with the condition. Key words: Benign, Soft tissue, Collagenous fibroma, Magnetic resonance imaging.

Case Report: A Novel Intronic Mutation in AIFM1 Associated With Fatal Encephalomyopathy and Mitochondrial Disease in Infant.

Background: The AIFM1 gene is located on chromosome Xq26.1 and encodes a flavoprotein essential for nuclear disassembly in apoptotic cells. Mutations in this gene can cause variable clinical phenotypes, but genotype-phenotype correlations of AIFM1-related disorder have not yet been fully determined because of the clinical scarcity. Case Presentation: We describe a 4-month-old infant with mitochondrial encephalopathy, carrying a novel intronic variant in AIFM1 (NM_004208.4: c.1164 + 5G > A). TA cloning of the complementary DNA (cDNA) and Sanger sequencing revealed the simultaneous presence of an aberrant transcript with exon 11 skipping (89 bp) and a normal transcript through analysis of mRNA extracted from the patient's fibroblasts, which is consistent with direct RNA sequencing results. Conclusion: We verified the pathogenic effect of the AIFM1 c.1164 + 5G > A splicing variant, which disturbed normal mRNA splicing. Our findings expand the mutation spectrum of AIFM1 and point out the necessity of intronic sequence analysis and the importance for integrative functional studies in the interpretation of sequence variants.

Auditory and imaging markers of atypical enlarged vestibular aqueduct.

PURPOSE: To characterize the auditory and imaging markers of atypical enlarged vestibular aqueduct (EVA). METHODS: 15 EVA cases (26 ears) confirmed via high-resolution MRI (HRMRI) that did not meet the Valvassori criterion on high-resolution CT (HRCT) were classified as atypical EVA. Another 21 EVA cases (40 ears) meeting the Valvassori criterion were randomly chosen as typical EVA. The hearing loss (HL), HRCT, and HRMRI findings were compared between the two groups. RESULTS: The difference of HL severity between atypical and typical EVA was not statistically significant (χ2 = 0.12, P > 0.05. The vestibular aqueducts (VA) of atypical EVA cases manifested as borderline dilation (n = 17), focal dilation (n = 3), and normal appearance (n = 6) on the HRCT. The midpoint width of atypical and typical EVA cases was 1.06 ± 0.18 mm and 2.10 ± 0.55 mm, respectively, exhibiting a significant difference (t = - 9.20, P < 0.05). In the HRMRI, the degree of dilation and shape of the intraosseous partition of endolymphatic duct and sac (ES) was similar to that of VA on HRCT, while their extraosseous ES was depicted variable slighter dilation compared to that of typical one, the difference between them was statistically significant (t = - 4.10, P < 0.05). CONCLUSION: The HL severity of atypical EVA ears was similar to that of typical ones. Nevertheless, borderline, focal dilation and normal-like appearance of VAs on HRCT and variablely slighter dilation of the extraosseous ES on HRMRI are its characteristic imaging findings.

ISM1 regulates NODAL signaling and asymmetric organ morphogenesis during development.

Isthmin1 (ISM1) was originally identified as a fibroblast group factor expressed in Xenopus laevis embryonic brain, but its biological functions remain unclear. The spatiotemporal distribution of ISM1, with high expression in the anterior primitive streak of the chick embryo and the anterior mesendoderm of the mouse embryo, suggested that ISM1 may regulate signaling by the NODAL subfamily of TGB-ß cytokines that control embryo patterning. We report that ISM1 is an inhibitor of NODAL signaling. ISM1 has little effect on TGF-ß1, ACTIVIN-A, or BMP4 signaling but specifically inhibits NODAL-induced phosphorylation of SMAD2. In line with this observation, ectopic ISM1 causes defective left-right asymmetry and abnormal heart positioning in chick embryos. Mechanistically, ISM1 interacts with NODAL ligand and type I receptor ACVR1B through its AMOP domain, which compromises the NODAL-ACVR1B interaction and down-regulates phosphorylation of SMAD2. Therefore, we identify ISM1 as an extracellular antagonist of NODAL and reveal a negative regulatory mechanism that provides greater plasticity for the fine-tuning of NODAL signaling.

Duplicated Internal Auditory Canal: High-Resolution CT and MRI Findings.

OBJECTIVE: To summarize the high-resolution computed tomography (HRCT) and magnetic resonance imaging (HRMRI) features of duplicated internal auditory canals (DIACs). MATERIALS AND METHODS: Ear HRCT data of 64813 patients with sensorineural hearing loss (SNHL), obtained between August 2009 and November 2017, were reviewed. Among these patients, 12 (13 ears) were found to have DIACs, 9 of whom underwent HRMRI. Their images were evaluated by two otoradiologists. RESULTS: The rate of occurrence of DIAC among SNHL patients was 0.019% (12/64813). The internal auditory canals of 13 ears were divided into double canals by complete (n = 6) and incomplete (n = 7) bony septa, with varied orientations ranging from horizontal to approximately vertical. All of the anterosuperior canals extended into the facial nerve (FN) canal, except for 1, which also extended to the vestibule. The posteroinferior canals ended in the cochlea and vestibule, except for 2, which also connected to the FN canals. Magnetic resonance images revealed that 77.8% (7/9) and 22.2% (2/9) of vestibulocochlear nerves (VCNs) were aplastic and hypoplastic, respectively. Furthermore, 88.9% (8/9) of FNs were normal, except for 1, which was hypoplastic. All of the affected ears also had other ear anomalies: a narrow, bony cochlear nerve canal was the most common other anomaly, accounting for 92.3% (12/13). Malformations of other systems were not found. CONCLUSION: Double-canal appearance is a characteristic finding of DIAC on HRCT, and it is usually accompanied by other ear anomalies. The VCN usually appears aplastic, with a normal FN, on HRMRI.

[Molecular and cytogenetic identification of Triticum aestivum-Leymus racemosus translocation line T6DL·7LrS].

Leymus racemosus had a high resistant capacity to wheat scab (Fusarum head blight). The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the germplasm of wheat resistance. To obtain Triticum aestivum-Leymus racemosus translocation line with scab resistance, we irradiated the pollen of T. aestivum-L. racemosus disomic addition line DA7Lr by 6°Co-γ-rays 1 200 R (100 R/min) prior to pollinating to emasculation T. aestivum cv. Chinese Spring. One plant with one translocation chromosome was detected in the M1 by GISH. The plant with one translocation chromosome was self-pollinated, and at meiotic metaphase I its progenies with two translocation chromosomes were analyzed for chromosome pairing behavior in their pollen mother cells (PMCs). One rod bivalent was observed at meiotic metaphase I, indicating that the plant with two translocation chromosomes was one translocation homozygote. Sequential GISH-FISH analysis, using Oligo-pAs1-2 and Oligo-pSc119.2-2 as probe, translocation line was confirmed as T6DL·7LrS. The translocation line had higher resistance to wheat scab and feasibility to be used as a new source in wheat breeding resistant to scab disease.

Structural and mechanistic insights into UHRF1-mediated DNMT1 activation in the maintenance DNA methylation.

UHRF1 plays multiple roles in regulating DNMT1-mediated DNA methylation maintenance during DNA replication. The UHRF1 C-terminal RING finger functions as an ubiquitin E3 ligase to establish histone H3 ubiquitination at Lys18 and/or Lys23, which is subsequently recognized by DNMT1 to promote its localization onto replication foci. Here, we present the crystal structure of DNMT1 RFTS domain in complex with ubiquitin and highlight a unique ubiquitin binding mode for the RFTS domain. We provide evidence that UHRF1 N-terminal ubiquitin-like domain (UBL) also binds directly to DNMT1. Despite sharing a high degree of structural similarity, UHRF1 UBL and ubiquitin bind to DNMT1 in a very distinct fashion and exert different impacts on DNMT1 enzymatic activity. We further show that the UHRF1 UBL-mediated interaction between UHRF1 and DNMT1, and the binding of DNMT1 to ubiquitinated histone H3 that is catalyzed by UHRF1 RING domain are critical for the proper subnuclear localization of DNMT1 and maintenance of DNA methylation. Collectively, our study adds another layer of complexity to the regulatory mechanism of DNMT1 activation by UHRF1 and supports that individual domains of UHRF1 participate and act in concert to maintain DNA methylation patterns.

Structure of the Active Platinum Cluster and Reaction Pathway of the Selective Synthesis of Phenol from Benzene and Oxygen Regulated with Ammonia on a Platinum Cluster/ß-Zeolite Catalyst Studied by DFT Calculations.

DFT calculations were used to investigate the structure of the active Pt cluster and the catalytic reaction pathway for the selective synthesis of phenol from benzene and molecular oxygen regulated with ammonia on a Pt cluster/ß-zeolite catalyst that was reported to be active for the selective hydroxylation of benzene only in the coexistence of ammonia. It was found that Pt5-Pt6 clusters were active for the direct synthesis of phenol, and they provided the reaction sites for bond rearrangements among ammonia, oxygen, and benzene; furthermore, the coexistence of ammonia was crucial for the selective oxidation of benzene to phenol, as it suppressed benzene combustion to CO2 and promoted the selective synthesis of phenol. It was further found that water coexisting in the system also played a significant role in desorbing phenol on the Pt cluster surface, which resulted in promotion of the overall selective synthesis of phenol. The energy diagram for the reaction sequences and the structures of the transition states were obtained, which indicated the origin of the Pt/ß catalysis.