9 research outputs found

    Reversible Unfolding and Folding of the Metalloprotein Ferredoxin Revealed by Single-Molecule Atomic Force Microscopy

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    Plant type [2Fe-2S] ferredoxins function primarily as electron transfer proteins in photosynthesis. Studying the unfolding–folding of ferredoxins in vitro is challenging, because the unfolding of ferredoxin is often irreversible due to the loss or disintegration of the iron–sulfur cluster. Additionally, the in vivo folding of holo-ferredoxin requires ferredoxin biogenesis proteins. Here, we employed atomic force microscopy-based single-molecule force microscopy and protein engineering techniques to directly study the mechanical unfolding and refolding of a plant type [2Fe-2S] ferredoxin from cyanobacteria Anabaena. Our results indicate that upon stretching, ferredoxin unfolds in a three-state mechanism. The first step is the unfolding of the protein sequence that is outside and not sequestered by the [2Fe-2S] center, and the second one relates to the force-induced rupture of the [2Fe-2S] metal center and subsequent unraveling of the protein structure shielded by the [2Fe-2S] center. During repeated stretching and relaxation of a single polyprotein, we observed that the completely unfolded ferredoxin can refold to its native holo-form with a fully reconstituted [2Fe-2S] center. These results demonstrate that the unfolding–refolding of individual ferredoxin is reversible at the single-molecule level, enabling new avenues of studying both folding–unfolding mechanisms, as well as the reactivity of the metal center of metalloproteins in vitro

    Additional file 1: of High-performance gene expression and knockout tools using sleeping beauty transposon system

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    Figure S1. Re-expression of Flag-tagged RCC2 rescued sgRCC2-mediated delay of mitotic exit. A. HeLa cells expressing GFP-H2B were incubated with Nocodazole (100 ng/ml) or Taxol (2 μM) for 12 h, and analyzed using ZEISS710 confocal microscope. (Scale bars, 2 μm). B. Immunoblots for control cells, RCC2-depleted cells, and RCC2-depleted cells stably expressing the indicated constructs. C. Time-lapse images showing mitotic exit in HeLa-H2B cells indicated above. Figure S2. Depletion of BRD7 delays mitotic exit and leads to spindle misorientation in HeLa cells. A. HeLa cells transfected with indicated sgRNA and synchronized in M phase by incubation with 100 ng/ml nocodazole for 14 h. M phase cells selected by shake-off were released for the indicated time. B. Time-lapse images showing prolonged metaphase to anaphase and misoriented cell division (uneven timing of daughter-cell adhesion to the substratum) in BRD7-depleted HeLa-H2B cells, compared with control. (Scale bars, 2 μm). (DOCX 7450 kb

    2D Hybrid Superlattice-Based On-Chip Electrocatalytic Microdevice for <i>in Situ</i> Revealing Enhanced Catalytic Activity

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    A molecule-confined two-dimensional (2D) hybrid superlattice is emerging for uncovering the chemical properties as well as distinctive physical phenomenon arising from the interface electronic states. An efficient and convenient synthetic method represents an important precondition to implementing the superlattice in terminal applications and functional devices. Herein, we develop an approach of spontaneous molecular intercalation to obtain a TaS2–N2H4 hybrid superlattice through simple solution immersion processing at room temperature. A cross-sectional high-angle annular dark field image verifies that the N2H4 molecules intercalate into the TaS2 lattice, and the interlayer spacing expands approximately 1.5 times. Combining electrical transport testing and theoretical calculations, electron transfer from N2H4 to the S–Ta–S lattice induces enhanced superconductivity and the suppression of the order of charge density waves. Moreover, electrical and Kelvin probe force microscope measurements reveal that intercalary N2H4 molecules ensure that the superlattice has higher conductivity and a lower surface work function at room temperature. A 2D hybrid superlattice-based on-chip electrocatalytic microdevice was fabricated through in situ molecular intercalation to directly evaluate the catalytic performance. Benefiting from electronic state regulation, the hybrid superlattice is more active. The presented intercalation method would aid in exploring efficient catalysts and discovering fundamental 2D physics

    Additional file 1 of Overexpression of lncRNAs with endogenous lengths and functions using a lncRNA delivery system based on transposon

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    Additional file 1: Figure S1. The performance of ELECTS. Figure S2. Representative images of xenograft tumors and the length of exogenous HOTAIRM1 products. Figure S3. Inappropriate termination of lncRNAs in the absent of BGH sequence results in differential secondary structures. Figure S4. Characterization of the liposome transfection system

    Supplementary Materials and Methods, Supplementary Figures 1 through 9, and Supplementary Tables 1 through 5 and 7 and 8 from PROTOCADHERIN 7 Acts through SET and PP2A to Potentiate MAPK Signaling by EGFR and KRAS during Lung Tumorigenesis

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    Supplementary Methods, References, and Figure Legends, Supplementary Fig. S1-High magnification images of PCDH7 IHC staining in normal human lung and lung adenocarcinomas. Supplementary Fig. S2-NSCLC tissue microarray analysis of PCDH7 immunoexpression. Supplementary Fig. S3-PCDH7 induces cellular transformation of HBEC cells and induces a gene expression program that promotes cell proliferation. Supplementary Fig. S4-All PCDH7 isoforms induce MAPK signaling in HBEC-shp53-KRASG12V cells. Supplementary Fig. S5-PCDH7 synergizes with mutant EGFR to promote tumor formation. Supplementary Fig. S6-CRISPR/Cas9-mediated inhibition of PCDH7 sensitizes NSCLC cells to MEK and ERK inhibitors. Supplementary Fig. S7-PCDH7 isoforms A, C, and D bind SET in EGFR-mutant cells. Supplementary Fig. S8-SET localization studies in HBECs and NSCLC cells and requirement of SET for PCDH7-induced MAPK pathway activation. Supplementary Fig. S9-Treatment of NSCLC cells with a SET inhibitor FTY720 induces cell death. Supplementary Table S1. Expression and survival analysis of PCDH family members in lung adenocarcinoma. Supplementary Table S2. Affymetrix probe IDs analyzed for each PCDH family member. Supplementary Table S3. Summary of clinical and pathologic information of the cohort of NSCLC patient tissue blocks used for TMA generation. Supplementary Table S4. Analysis of tissue microarray correlations. Supplementary Table S5. Correlation between PCDH7 upregulation and alterations in KRAS or EGFR. Supplementary Table S7. List of antibodies utilized in this study. Supplementary Table S8. List of primer sequences utilized in this study.</p
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