Heterobimetallic Cobalt/Rhodium Nanoparticle-Catalyzed Carbonylative Cycloaddition of 2-Alkynylanilines to Oxindoles

The cobalt−rhodium heterobimetallic nanoparticle-catalyzed synthesis of oxindoles from 2-alkynylanilines in the presence of carbon monoxide is described

Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction: Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide [<i>J. Am. Chem. Soc.</i> <b>2004</b>, <i>126</i>, 2714−2715].

Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction:  Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide [J. Am. Chem. Soc. 2004, 126, 2714−2715]

Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction: Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide [<i>J. Am. Chem. Soc.</i> <b>2004</b>, <i>126</i>, 2714−2715].

Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction:  Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide [J. Am. Chem. Soc. 2004, 126, 2714−2715]

Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction: Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide

The rhodium-catalyzed carbonylative [3+2+1] cycloaddition of trienes into bicyclohexenones has been developed. The carbonylated cycloaddition products have a high regioselectivity. This catalytic system tolerates functionalities including ether, sulfonamide, and ester

Cobalt−Rhodium Heterobimetallic Nanoparticle-Catalyzed Synthesis of α,β-Unsaturated Amides from Internal Alkynes, Amines, and Carbon Monoxide

The first example of cobalt−rhodium heterobimetallic nanoparticle-catalyzed synthesis of alkenyl amides from alkynes, amines, and carbon monoxide is described

Enhanced Dehydrogenative H₂ Release from <i>N</i>‑Containing Amphicyclic LOHC Boosted by Pd-Supported Nanosheet MFI Zeolites Having Strong Acidity and Large Mesoporosity

The amount and rate of H2 discharge from 2-[(n-methylcyclohexyl)­methyl]­piperidine (H12-MBP), an amphicyclic liquid organic hydrogen carrier (LOHC) having two cycle moieties (cyclohexane and piperidine) with different reactivities, are determined by dehydrogenation of a cyclohexane ring with less reactivity. To realize high H2 yields with rapid kinetics, the cyclohexane ring in the partially dehydrogenated 2-[n-methylcyclohexyl]­methyl)­pyridine (H6-MBP) that is generated as the intermediate species should be fully dehydrogenated to 2-(n-methylbenzyl)­pyridine (H0-MBP). This is approached using Pd-supported nanosheet zeolites having mesoporous structures bearing high concentrations of strongly acidic sites on external surfaces, which can not only enhance the diffusion of bulky H12-MBP but also strongly bind the basic piperidine ring in H12-MBP and H6-MBP. The H2 yields and rate constants are correlated with the acidity, mesoporosity, and adsorption behaviors of the LOHCs. As these factors are strengthened, H2 yield and rate constants increased dramatically within the ranges of 16.0–64.7% and 0.0001–0.0013 min–1, respectively. The results prove that mesoporous zeolites can be used for constructing supported Pd catalysts achieving high H2 yields with rapid kinetics from N-containing amphicyclic LOHCs

eIF4GI participates in the miRNA-mediated gene silencing.

<p>(<i>A</i>) Schematic diagrams of the reporter constructs for the investigation of the miRNA-mediated gene silencing. pcDNA3.1-FL-6×Bulge expresses a FL mRNA containing six imperfect repeats of the miCXCR4-binding site. pcDNA3.1-FL expresses a FL mRNA lacking the miCXCR4-binding site. Abbreviations: P_CMV, the CMV promoter; P_T7, the T7 promoter; FL, firefly luciferase. (<i>B</i>) HeLa cells cultivated on a 24-well plate were transfected with the reporter plasmids in the presence of miControl or miCXCR4. After 24 h of incubation, the luciferase activities were measured by a dual luciferase assay. The activity ratios of FL to RL (FL/RL) were calculated, and the relative values were determined by setting the value from miControl-treated cells to 100%. (<i>C</i>) Total RNAs from the cells described in panel <i>B</i> were extracted, and the levels of reporter mRNAs were analyzed by Northern blotting. The EtBr-staining of 28S rRNAs was assessed as a control for total RNA levels. (<i>D</i>) De-repression of the miRNA-mediated gene silencing by siRNAs against translation initiation factors. The overall experimental procedures and analyses were described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055725#s2" target="_blank">Materials and Methods</a>. (<i>E</i>) The relative amounts of the reporter mRNAs in panel <i>D</i> were measured by quantitative RT-PCR analysis. The ratios of FL/RL mRNAs obtained from miCXCR4-treated cells were first normalized by that of miControl-treated cells and then relatively presented by setting the value from miControl/si-Control-treated cells to 100% (lane 1). (<i>F</i>) The knock-down efficiency of each siRNA was examined by Western blotting using the indicated antibodies. For comparison, WCEs from mock-transfected HeLa cells (100–0%; denoted as Mock) were loaded in lanes 1–6. All experiments were performed in triplicate. In panels <i>B</i> and <i>D</i>, the P-values are described (Student <i>t</i>-test). Standard deviations are indicated by bars.</p

CD63 participates in HCV entry through a direct interaction with HCV E2.

<p>(A) Co-immunoprecipitations of CD63 and CD81 by HCV E2. Extracts of Huh 7.5.1 cells, which were infected with JC1 E2 FLAG virus (MOI 0.3) for 72 hrs, were analyzed by Western blotting to detect the indicated proteins before and after immunoprecipitations with a FLAG antibody or a control mouse antibody. Actin is a negative control. (B) GST pull-down assays with purified proteins. GST-fused CD63 EC2 (GST-CD63) and GST-fused CD81 LEL (GST-CD81) proteins were expressed in <i>E. coli</i> and then purified (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060333#s2" target="_blank">Methods</a>). FLAG-tagged HCV E2 (FLAG-E2) proteins were expressed in yeast and then purified (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060333#s2" target="_blank">Methods</a>). After incubating the purified FLAG-E2 proteins with GST, GST-CD81 or GST-CD63 proteins for 2 hrs at 4°C, GST, GST-fusion proteins, and their associated proteins were precipitated with GSH Sepharose 4B. The resin-bound proteins were analyzed by Western blotting with antibodies against GST or FLAG. Degraded forms of GST-CD63 and GST-CD81 (indicated by asterisks) were also precipitated by the GSH resin. (C) Effect of a polypeptide corresponding to the CD63 EC2 domain on HCV infection. JFH1 5A-Rluc virus was incubated with GST or GST-CD63 for 2 hrs at 4°C. Huh7.5.1 cells were then inoculated with the virus–polypeptide mixtures by incubating for 3 hrs at 37°C, and the cells were further cultivated for 48 hrs. Virus infectivity was monitored by measuring Renilla luciferase activities in cell extracts, and normalized to the amounts of proteins in cell extracts (mean ± s.d. from three independent experiments performed in duplicate). The relative luciferase activities in experimental lysates to that in the control lysate (PBS) are depicted. (D) Effect of an anti-CD63 antibody (BEM-1 from Santa Cruz Biotechnologies) on HCV infection. Huh7.5.1 cells were pre-incubated with a negative control mouse IgG1, a positive control anti-CD81 antibody, or an anti-CD63 antibody at the indicated concentrations for 1 hour at 37°C, and then inoculated with JFH1 5A-Rluc virus (MOI of 0.3). The cells were cultivated for additional 48 hrs, and then Renilla luciferase activities in cell lysates were measured and normalized to the amounts of proteins in lysates (mean ± s.d. from three independent experiments performed in duplicate). The relative luciferase activities in experimental lysates to that in the control lysate (PBS) are depicted.</p

eIF4GI Facilitates the MicroRNA-Mediated Gene Silencing

<div><p>MicroRNAs (miRNAs) are small noncoding RNAs that mediate post-transcriptional gene silencing by binding to complementary target mRNAs and recruiting the miRNA-containing ribonucleoprotein complexes to the mRNAs. However, the molecular basis of this silencing is unclear. Here, we show that human Ago2 associates with the cap-binding protein complex and this association is mediated by human eIF4GI, a scaffold protein required for the translation initiation. Using a cap photo-crosslinking method, we show that Ago2 closely associates with the cap structure. Taken together, these data suggest that eIF4GI participates in the miRNA-mediated post-transcriptional gene silencing by promoting the association of Ago2 with the cap-binding complex.</p> </div

eIF4GI mediates the Ago2-cap association.

<p>(<i>A</i>) Identification of a translation initiation factor capable of augmenting the Ago2-cap association. WCEs from 293FT cells co-transfected with plasmids expressing myc-Ago2 and Flag-tagged translation factors (eIF3c, eIF4AI, eIF4E, eIF4GI and PABP) were subjected to cap-pulldown assays. The expression levels of the transfected genes (lanes 1–6), their cap-associations (lanes 7–12), and various proteins from WCEs or from the resin-bound fractions were monitored by Western blotting with the indicated antibodies. (<i>B</i>) The eIF4GI-dependent cap-association of Ago2. WCE from HeLa cells transfected with si-Control or si-eIF4GI were applied to cap-pulldown assays. The knock-down efficiency of siRNAs and the resin-bound proteins were monitored using antibodies described. (<i>C</i>) Determination of a domain in eIF4GI responsible for augmenting the Ago2-cap association. WCEs from 293FT cells transiently expressing myc-Ago2 and Flag-tagged fragments encoding the N-terminal, middle or C-terminal regions of eIF4GI (depicted in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055725#pone-0055725-g005" target="_blank">Figure 5A</a>) were subjected to cap-pulldown assays. The resin-bound Ago2 (upper panel), the ectopically expressed Ago2 and eIF4GI fragments (lower panel), GAPDH and eIF4E proteins were detected using the indicated antibodies.</p