Poly-SUMO-2/3 chain modification of Nuf2 facilitates CENP-E kinetochore localization and chromosome congression during mitosis.

SUMO modification is required for the kinetochore localization of the kinesin-like motor protein CENP-E, which subsequently mediates the alignment of chromosomes to the spindle equator during mitosis. However, the underlying mechanisms by which sumoylation regulates CENP-E kinetochore localization are still unclear. In this study, we first elucidate that the kinetochore protein Nuf2 is not only required for CENP-E kinetochore localization but also preferentially modified by poly-SUMO-2/3 chains. In addition, poly-SUMO-2/3 modification of Nuf2 is significantly upregulated during mitosis, which is temporally correlated to the kinetochore localization of CENP-E during mitosis. We further show that the mitotic defects in CENP-E kinetochore localization and chromosome congression caused by global inhibition of sumoylation can be rescued by expressing a fusion protein between Nuf2 and the SUMO-conjugating enzyme Ubc9 for stimulating Nuf2 SUMO-2/3 modification. Moreover, the expression of another fusion protein between Nuf2 and three SUMO-2 moieties (SUMO-2 trimer), which mimics the trimeric SUMO-2/3 chain modification of Nuf2, can also rescue the mitotic defects due to global inhibition of sumoylation. Conversely, expressing the other forms of Nuf2-SUMO fusion proteins, which imitate Nuf2 modifications by SUMO-2/3 monomer, SUMO-2/3 dimer, and SUMO-1 trimer, respectively, cannot rescue the same mitotic defects. Lastly, compared to Nuf2, the fusion protein simulating the trimeric SUMO-2 chain-modified Nuf2 exhibits a significantly higher binding affinity to CENP-E wild type containing a functional SUMO-interacting motif (SIM) but not the CENP-E SIM mutant. Hence, our results support a model that poly-SUMO-2/3 chain modification of Nuf2 facilitates CENP-E kinetochore localization and chromosome congression during mitosis.Abbreviations: CENP-E, centromere-associated protein E; SUMO, small ubiquitin-related modifier; SIM, SUMO-interacting motif.

A Fluorescent Sensor of 3-Aminobenzeneboronic Acid Functionalized Hydrothermal Carbon Spheres for Facility Detection of L-tryptophan.

In the paper, hydrothermal carbon spheres (HTCs) are functionalized by the 3-aminobenzeneboronic acid (3-APBA) as a fluorescence sensor. The modification carbon spheres (3-APBA-HTCs) have shown excellent selectivity and sensitivity for efficient determination of L-tryptophan (L-Trp). The fluorescence sensor can selectively achieve the "On-Off" switchable functionality for L-Trp at an extremely low detection limit of 0.50 × 10- 5 mol/L.

[Clinical observation of modified Da Chaihu decoction in treating essential hypertension with anxiety].

To observe the clinical efficacy of modified Da Chaihu decoction in treating essential hypertension with anxiety, the randomized, controlled, clinical trial was performed in this study. One hundred and twenty-six hypertensive patients with anxiety meeting the inclusive criteria were randomized into the treatment group and the control group. All of the included patients in the above 2 groups were treated by amlodipine besylate tablets. Patients in the treatment group were given Chinese herbal medicine modified Da Chaihu decoction every day. And patients in the control group were given flupentixol and melitracen tablets. The treatment course was 4 weeks. Blood pressure, the score of traditional Chinese medicine syndrome, blood lipids, C reactive protein, the Hamilton anxiety scale score and adverse effects were observed. It has been identified that, both systolic and diastolic blood pressure were significantly reduced (P<0.05). However, no significant difference between the treatment group and the control group was identified. For traditional Chinese medicine syndrome, it was significantly improved in the treatment group (P<0.05). For blood lipids, TC, TG, HDL-C, and LDL-C were significantly improved in the treatment group (P<0.05). After treatment, only TC was significantly reduced in the treatment group when compared to the control group (P<0.05). For C reactive protein, it was significantly reduced in the treatment group after treatment (P<0.05). For anxiety, no significant difference between the treatment group and the control group on the Hamilton anxiety scale score was identified. For adverse effect, no severe adverse effect was identified in this study. The modified Da Chaihu decoction maybe effective in the treatment of essential hypertension with anxiety. In addition to a certain role in lowering blood pressure, the modified Da Chaihu decoction was also effective in improving traditional Chinese medicine syndrome and blood lipids, reducing the level of C reactive protein, relieving anxiety with little adverse effect.

Qualitative and Quantitative Characterization of Monosaccharide Components of Salvia miltiorrhiza, Liguspyragine Hydrochloride, and Glucose Injection.

Salvia miltiorrhiza, liguspyragine hydrochloride, and glucose injection (SLGI) was made of Salvia miltiorrhiza Bge., liguspyragine hydrochloride, glucose, and glycerin. There were many kinds of monosaccharide components in SLGI, which might be from the raw material and Salvia miltiorrhiza Bge. Separation was performed on a Phenomenex Luna C18 analytical column (250 mm × 4.6 mm i.d., 5 µm, AccuStandard Inc., USA) at 30°C. The mobile phase consisted of two solvents: 0.1 mol/L phosphate-buffered saline (pH 6.7) (solvent A) and acetonitrile (solvent B) with gradient elution. The flow rate was maintained at 1.0 mL/min. Five kinds of monosaccharide components, glucose, D-mannose, L-rhamnose monohydrate, galactose, and xylose, were detected by precolumn derivatization HPLC, and their contents were compared with each other. And finally, concentrations of glucose in SLGI were determined and they were higher than the values of marked amount, which showed that one source of glucose might be from Salvia miltiorrhiza Bge. in SLGI. The average concentration of glucose was 5.18 g/100 mL, which was near the average value at 5.25 g/100 mL detected by ultraviolet spectrophotometry and also close to the marked amount (5.00 g/100 mL) on the label.

Molecular Characterization and Functional Analysis of Annulate Lamellae Pore Complexes in Nuclear Transport in Mammalian Cells.

Annulate lamellae are cytoplasmic organelles containing stacked sheets of membranes embedded with pore complexes. These cytoplasmic pore complexes at annulate lamellae are morphologically similar to nuclear pore complexes at the nuclear envelope. Although annulate lamellae has been observed in nearly all types of cells, their biological functions are still largely unknown. Here we show that SUMO1-modification of the Ran GTPase-activating protein RanGAP1 not only target RanGAP1 to its known sites at nuclear pore complexes but also to annulate lamellae pore complexes through interactions with the Ran-binding protein RanBP2 and the SUMO-conjugating enzyme Ubc9 in mammalian cells. Furthermore, upregulation of annulate lamellae, which decreases the number of nuclear pore complexes and concurrently increases that of annulate lamellae pore complexes, causes a redistribution of nuclear transport receptors including importin α/ß and the exportin CRM1 from nuclear pore complexes to annulate lamellae pore complexes and also reduces the rates of nuclear import and export. Moreover, our results reveal that importin α/ß-mediated import complexes initially accumulate at annulate lamellae pore complexes upon the activation of nuclear import and subsequently disassociate for nuclear import through nuclear pore complexes in cells with upregulation of annulate lamellae. Lastly, CRM1-mediated export complexes are concentrated at both nuclear pore complexes and annulate lamellae pore complexes when the disassembly of these export complexes is inhibited by transient expression of a Ran GTPase mutant arrested in its GTP-bound form, suggesting that RanGAP1/RanBP2-activated RanGTP hydrolysis at these pore complexes is required for the dissociation of the export complexes. Hence, our findings provide a foundation for further investigation of how upregulation of annulate lamellae decreases the rates of nuclear transport and also for elucidation of the biological significance of the interaction between annulate lamellae pore complexes and nuclear transport complexes in mammalian cells.

The Cellular Distribution of RanGAP1 Is Regulated by CRM1-Mediated Nuclear Export in Mammalian Cells.

The Ran GTPase activating protein RanGAP1 plays an essential role in nuclear transport by stimulating RanGTP hydrolysis in the cytoplasmic compartment. In mammalian cells, unmodified RanGAP1 is predominantly cytoplasmic, whereas modification by small ubiquitin-related modifier protein (SUMO) targets RanGAP1 to the cytoplasmic filaments of nuclear pore complex (NPC). Although RanGAP1 contains nine putative nuclear export signals and a nuclear localization signal, little is known if RanGAP1 shuttles between the nuclear and cytoplasmic compartments and how its primary localization in the cytoplasm and at the NPC is regulated. Here we show that inhibition of CRM1-mediated nuclear export using RNAi-knockdown of CRM1 and inactivation of CRM1 by leptomycin B (LMB) results in nuclear accumulation of RanGAP1. LMB treatment induced a more robust redistribution of RanGAP1 from the cytoplasm to the nucleoplasm compared to CRM1 RNAi and also uniquely triggered a decrease or loss of RanGAP1 localization at the NPC, suggesting that LMB treatment is more effective in inhibiting CRM1-mediated nuclear export of RanGAP1. Our time-course analysis of LMB treatment reveals that the NPC-associated RanGAP1 is much more slowly redistributed to the nucleoplasm than the cytoplasmic RanGAP1. Furthermore, LMB-induced nuclear accumulation of RanGAP1 is positively correlated with an increase in levels of SUMO-modified RanGAP1, suggesting that SUMOylation of RanGAP1 may mainly take place in the nucleoplasm. Lastly, we demonstrate that the nuclear localization signal at the C-terminus of RanGAP1 is required for its nuclear accumulation in cells treated with LMB. Taken together, our results elucidate that RanGAP1 is actively transported between the nuclear and cytoplasmic compartments, and that the cytoplasmic and NPC localization of RanGAP1 is dependent on CRM1-mediated nuclear export.

Characterization of amino acid residues within the N-terminal region of Ubc9 that play a role in Ubc9 nuclear localization.

As the sole E2 enzyme for SUMOylation, Ubc9 is predominantly nuclear. However, the underlying mechanisms of Ubc9 nuclear localization are still not well understood. Here we show that RNAi-depletion of Imp13, an importin known to mediate Ubc9 nuclear import, reduces both Ubc9 nuclear accumulation and global SUMOylation. Furthermore, Ubc9-R13A or Ubc9-H20D mutation previously shown to interrupt the interaction of Ubc9 with nucleus-enriched SUMOs reduces the nuclear enrichment of Ubc9, suggesting that the interaction of Ubc9 with the nuclear SUMOs may enhance Ubc9 nuclear retention. Moreover, Ubc9-R17E mutation, which is known to disrupt the interaction of Ubc9 with both SUMOs and Imp13, causes a greater decrease in Ubc9 nuclear accumulation than Ubc9-R13A or Ubc9-H20D mutation. Lastly, Ubc9-K74A/S89D mutations that perturb the interaction of Ubc9 with nucleus-enriched SUMOylation-consensus motifs has no effect on Ubc9 nuclear localization. Altogether, our results have elucidated that the amino acid residues within the N-terminal region of Ubc9 play a pivotal role in regulation of Ubc9 nuclear localization.

Identification of SUMO-2/3-modified proteins associated with mitotic chromosomes.

Sumoylation is essential for progression through mitosis, but the specific protein targets and functions remain poorly understood. In this study, we used chromosome spreads to more precisely define the localization of SUMO-2/3 (small ubiquitin-related modifier) to the inner centromere and protein scaffold of mitotic chromosomes. We also developed methods to immunopurify proteins modified by endogenous, untagged SUMO-2/3 from mitotic chromosomes. Using these methods, we identified 149 chromosome-associated SUMO-2/3 substrates by nLC-ESI-MS/MS. Approximately one-third of the identified proteins have reported functions in mitosis. Consistent with SUMO-2/3 immunolocalization, we identified known centromere- and kinetochore-associated proteins, as well as chromosome scaffold associated proteins. Notably, >30 proteins involved in chromatin modification or remodeling were identified. Our results provide insights into the roles of sumoylation as a regulator of chromatin structure and other diverse processes in mitosis. Furthermore, our purification and fractionation methodologies represent an important compliment to existing approaches to identify sumoylated proteins using exogenously expressed and tagged SUMOs.

Direct asymmetric hydrogenation of α-keto acids by using the highly efficient chiral spiro iridium catalysts.

A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.

[Optimization of enzymatic extraction of polysaccharide from Dendrobium officinale by box-Behnken design and response surface methodology].

OBJECTIVE: To optimize the processing of enzymatic extraction of polysaccharide from Dendrobium officinale. METHODS: With phenol-sulfuric acid method and the DNS determination polysaccharide, Box-Behnken response surface methodology was used to optimize different enzyme dosage, reaction temperature and reaction time by using Design-Expert 8.05 software for data analysis and processing. RESULTS: According to Box-Behnken response, the best extraction conditions for the polysaccharide from Dendrobium officinale were as follows: the amount of enzyme complex was 3.5 mg/mL, hydrolysis temperature was 53 degrees C, and reaction time was 70 min. In accordance with the above process, the polysaccharide yield was 16.11%. CONCLUSION: Box-Behnken response surface methodology is used to optimize the enzymatic extraction process for the polysaccharide in this study, which is effective, stable and feasible.

Analysis of changes in SUMO-2/3 modification during breast cancer progression and metastasis.

SUMOylation is an essential posttranslational modification and regulates many cellular processes. Dysregulation of SUMOylation plays a critical role in metastasis, yet how its perturbation affects this lethal process of cancer is not well understood. We found that SUMO-2/3 modification is greatly up-regulated in metastatic breast cancer cells compared with nonmetastatic control cells. To identify proteins differentially modified by SUMO-2/3 between metastatic and nonmetastatic cells, we established a method in which endogenous SUMO-2/3 conjugates are labeled by stable isotope labeling by amino acids in cell culture (SILAC), immunopurified by SUMO-2/3 monoclonal antibodies and epitope-peptide elution, and analyzed by quantitative mass spectrometry. We identified 66 putative SUMO-2/3-conjugated proteins, of which 15 proteins show a significant increase/decrease in SUMO-2/3 modification in metastatic cells. Targets with altered SUMOylation are involved in cell cycle, migration, inflammation, glycolysis, gene expression, and SUMO/ubiquitin pathways, suggesting that perturbations of SUMO-2/3 modification might contribute to metastasis by affecting these processes. Consistent with this, up-regulation of PML SUMO-2/3 modification corresponds to an increased number of PML nuclear bodies (PML-NBs) in metastatic cells, whereas up-regulation of global SUMO-2/3 modification promotes 3D cell migration. Our findings provide a foundation for further investigating the effects of SUMOylation on breast cancer progression and metastasis.

[Study on the immunocompetence of polysaccharide extracted from root of Salvia miltiorrhiza].

OBJECTIVE: To study the immune activity of polysaccharide extracted from root of Salvia miltiorrhiza. METHODS: Investigated the effects of polysaccharide extracted from root of Salvia miltiorrhiza on lymphocyte proliferation response of mouse induced by LPS (the lipopolysaccharide LPS), phagocytosis of the peritoneal macrophage of mice to chick erythrocytes and the mouse models of delayed type hypersensitivity (DTH) response induced by DNFB. RESULTS: Lymphocyte proliferation and phagocytosis of the peritoneal macrophage of mice could be promoted by the polysaccharide, which could inhibit ear edema and capillary permeability increase induced by DNFB and enlarged the thymus and splenic index in mice. The expression of iNOS, IFN-alpha and IL-1beta was inhibited significantly in the treatment group. CONCLUSION: The polysaccharide extracted from Salvia miltiorrhiza can improve immune function.

SUMOylation in control of accurate chromosome segregation during mitosis.

Posttranslational protein modification by small ubiquitin-related modifier (SUMO) has emerged as an important regulatory mechanism for chromosome segregation during mitosis. This review focuses on how SUMOylation regulates the centromere and kinetochore activities to achieve accurate chromosome segregation during mitosis. Kinetochores are assembled on the specialized chromatin domains called centromeres and serve as the sites for attaching spindle microtubule to segregate sister chromatids to daughter cells. Many proteins associated with mitotic centromeres and kinetochores have been recently found to be modified by SUMO. Although we are still at the early stage of elucidating how SUMOylation controls chromosome segregation during mitosis, a substantial progress has been achieved over the past decade. Furthermore, a major theme that has emerged from the recent studies of SUMOylation in mitosis is that both SUMO conjugation and deconjugation are critical for kinetochore assembly and disassembly. Lastly, we propose a model that SUMOylation coordinates multiple centromere and kinetochore activities to ensure accurate chromosome segregation.

Synthesis of PVP-coated ultra-small Fe3O4 nanoparticles as a MRI contrast agent.

Ultra-small Fe(3)O(4) nanoparticles were prepared by using the coprecipitation method, in which the polyvinylpyrrolidone (PVP) serves as a stabilizer. The nanoparticles were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), infra spectrum (IR), X-ray photoelectron spectroscopy (XPS) and in vivo magnetic resonance imaging (MRI) test. The results showed that the particles' size was determined by the dripping rate and that PVP molecules played the role of preventing the aggregation and restricting the size of Fe(3)O(4) nanoparticles. The Fe(3)O(4) nanoparticles with diameter from 6.5 to 1.9 nm obviously exhibited negative contrast enhancement and concentrated at the target area guided by a permanent magnet.

An improved SUMmOn-based methodology for the identification of ubiquitin and ubiquitin-like protein conjugation sites identifies novel ubiquitin-like protein chain linkages.

Ubiquitin (Ub) and the ubiquitin-like proteins (Ubls) comprise a remarkable assortment of polypeptides that are covalently conjugated to target proteins (or other biomolecules) to modulate their intracellular localization, half-life, and/or activity. Identification of Ub/Ubl conjugation sites on a protein of interest can thus be extremely important for understanding how it is regulated. While MS has become a powerful tool for the study of many classes of PTMs, the identification of Ub/Ubl conjugation sites presents a number of unique challenges. Here, we present an improved Ub/Ubl conjugation site identification strategy, utilizing SUMmOn analysis and an additional protease (lysyl endopeptidase C), as a complement to standard approaches. As compared with standard trypsin proteolysis-database search protocols alone, the addition of SUMmOn analysis can (i) identify Ubl conjugation sites that are not detected by standard database searching methods, (ii) better preserve Ub/Ubl conjugate identity, and (iii) increase the number of identifications of Ub/Ubl modifications in lysine-rich protein regions. Using this methodology, we characterize for the first time a number of novel Ubl linkages and conjugation sites, including alternative yeast (K54) and mammalian small ubiquitin-related modifier (SUMO) chain (SUMO-2 K42, SUMO-3 K41) assemblies, as well as previously unreported NEDD8 chain (K27, K33, and K54) topologies.

PARP-1 transcriptional activity is regulated by sumoylation upon heat shock.

Heat shock and other environmental stresses rapidly induce transcriptional responses subject to regulation by a variety of post-translational modifications. Among these, poly(ADP-ribosyl)ation and sumoylation have received growing attention. Here we show that the SUMO E3 ligase PIASy interacts with the poly(ADP-ribose) polymerase PARP-1, and that PIASy mediates heat shock-induced poly-sumoylation of PARP-1. Furthermore, PIASy, and hence sumoylation, appears indispensable for full activation of the inducible HSP70.1 gene. Chromatin immunoprecipitation experiments show that PIASy, SUMO and the SUMO-conjugating enzyme Ubc9 are rapidly recruited to the HSP70.1 promoter upon heat shock, and that they are subsequently released with kinetics similar to PARP-1. Finally, we provide evidence that the SUMO-targeted ubiquitin ligase RNF4 mediates heat-shock-inducible ubiquitination of PARP-1, regulates the stability of PARP-1, and, like PIASy, is a positive regulator of HSP70.1 gene activity. These results, thus, point to a novel mechanism for regulating PARP-1 transcription function, and suggest crosstalk between sumoylation and RNF4-mediated ubiquitination in regulating gene expression in response to heat shock.

[Influences of intervention on the abilities of detecting pulmonary tuberculosis cases in general hospitals].

OBJECTIVE: To explore the influences of intervention on the abilities of detecting pulmonary tuberculosis cases in general hospitals. METHODS: We selected 6 general hospitals at 3 different levels (A, B, and C). The intervened group included hospitals A1, B1, and C1, and the non-intervened group included hospitals A2, B2, and C2. The results after intervention were compared. RESULTS: The report rate of pulmonary tuberculosis, sputum positive rate of reported cases, and sputum check rate of reported cases were significantly higher in hospital A1 than grouping hospital A2 (P = 0.000, P = 0.045, and P = 0.017, respectively). The report rate and sputum examination rate of reported cases were significantly higher in hospital B1 than grouping hospital B2 (P = 0.000, P = 0.024, respectively). The report rate and sputum examination rate of reported cases were significantly lower in hospital C1 than grouping hospital C2 (P = 0.000, P = 0.001, respectively). In hospital A1, the report rate, sputum positive rate of reported cases, and sputum check rate of reported cases were not significantly different before and after intervention (P = 0.182, P = 0.116, and P = 0.583, respectively). In hospital B1, the report rate were significantly different before and after intervention (P = 0.004), while the sputum positive rate of reported cases and sputum check rate of reported cases were not significantly different (P = 0.909, P = 0.052, respectively). In hospital C1, the report rate was significantly higher after intervention (P = 0.025). In hospital C2, the sputum check rate significantly increased (P = 0.000). CONCLUSIONS: Intervention influences the hospitals abilities to detect pulmonary tuberculosis cases. However, more optimized and long-term intervention mechanism should be established to increase case detection rate of pulmonary tuberculosis.

[Investigation on damage of bovine serum albumin (BSA) catalyzed by nano-sized silicon dioxide (SiO2) under ultrasonic irradiation using spectral methods].

The damage of bovine serum albumin (BSA) molecules under ultrasonic irradiation in the presence of nano-sized silicon dioxide (SiO2) particles was studied by UV-Vis and fluorescence spectra. In addition, the influences of ultrasonic irradiation time, nano-sized SiO2 addition amount, solution acidity (pH) and ultrasonic irradiation power on the damage of BSA molecules in aqueous solution were also detected. For BSA solution of 1.0 x 10(-5) mol x L(-1) at (37.0+/-0.2) degrees C, the UV-Vis spectra of BSA solutions showed that the absorption peaks of BSA displayed obvious hyperchromic effect with the increase in some influence factors such as ultrasonic irradiation time, nano-sized SiO2 addition amount, pH value and ultrasonic irradiation power. However, the fluorescence spectra of BSA solutions showed the phenomenon of fluorescence quenching with the increase in ultrasonic irradiation time, nano-sized SiO2 addition amount, pH value and ultrasonic irradiation power. Moreover, the possible mechanism behind the damage of BSA molecule in the presence of nano-sized SiO2 powders under ultrasonic irradiation was discussed. It was considered that the damage of BSA molecules was attributed to the formation of *OH radicals resulting from the sonoluminescence and high-heat excitation of ultrasonic cavitation. The research results could be of great significance to using sonocatalytic method to treat tumour in clinic application and for developing nano-sized drug in the future.

Protection from isopeptidase-mediated deconjugation regulates paralog-selective sumoylation of RanGAP1.

Vertebrates express three small ubiquitin-related modifiers (SUMO-1, SUMO-2, and SUMO-3) that are conjugated in part to unique subsets of proteins and, thereby, regulate distinct cellular processes. Mechanisms regulating paralog-selective sumoylation, however, remain poorly understood. Despite being equally well modified by SUMO-1 and SUMO-2 in vitro, RanGAP1 is selectively modified by SUMO-1 in vivo. We have found that this paralog-selective modification is determined at the level of deconjugation by isopeptidases. Our findings indicate that, relative to SUMO-2-modified RanGAP1, SUMO-1-modified RanGAP1 forms a more stable, higher affinity complex with the nucleoporin Nup358/RanBP2 that preferentially protects it from isopeptidases. By swapping residues in SUMO-1 and SUMO-2 responsible for Nup358/RanBP2 binding, or by manipulating isopeptidase expression levels, paralog-selective modification of RanGAP1 could be affected both in vitro and in vivo. Thus, protection from isopeptidases, through interactions with SUMO-binding proteins, represents an important mechanism defining paralog-selective sumoylation.