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  1. Article ; Online: Improvement of the signal to noise ratio for fluorescent imaging in microfluidic chips

    Xiaocheng Liu / Hanliang Zhu / Ján Sabó / Zdeněk Lánský / Pavel Neužil

    Scientific Reports, Vol 12, Iss 1, Pp 1-

    2022  Volume 9

    Abstract: Abstract Microfluidics systems can be fabricated in various ways using original silicon glass systems, with easy Si processing and surface modifications for subsequent applications such as cell seeding and their study. Fluorescent imaging of cells became ...

    Abstract Abstract Microfluidics systems can be fabricated in various ways using original silicon glass systems, with easy Si processing and surface modifications for subsequent applications such as cell seeding and their study. Fluorescent imaging of cells became a standard technique for the investigation of cell behavior. Unfortunately, high sensitivity fluorescent imaging, e.g., using total internal reflection fluorescence (TIRF) microscopy, is problematic in these microfluidic systems because the uneven surfaces of the silicon channels’ bottoms affect light penetration through the optical filters. In this work, we study the nature of the phenomenon, finding that the problem can be rectified by using a silicon-on-insulator (SOI) substrate, defining the channel depth by the thickness of the top Si layer, and halting the etching at the buried SiO2 layer. Then the fluorescent background signal drops by = 5 times, corresponding to the limit of detection drop from = 0.05 mM to = 50 nM of fluorescein. We demonstrate the importance of a flat surface using TIRF-based single-molecule detection, improving the signal to a noise ratio more than 18 times compared to a conventional Si wafer. Overall, using very high-quality SOI substrates pays off, as it improves the fluorescence image quality due to the increase in signal-to-noise ratio. Concerning the cost of microfluidic device fabrication—design, mask fabrication, wafer processing, and device testing—the initial SOI wafer cost is marginal, and using it improves the system performance.
    Keywords Medicine ; R ; Science ; Q
    Subject code 621
    Language English
    Publishing date 2022-11-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Lab-on-chip microscope platform for electro-manipulation of a dense microtubules network

    Daniel Havelka / Ilia Zhernov / Michal Teplan / Zdeněk Lánský / Djamel Eddine Chafai / Michal Cifra

    Scientific Reports, Vol 12, Iss 1, Pp 1-

    2022  Volume 12

    Abstract: Abstract Pulsed electric field (PEF) technology is promising for the manipulation of biomolecular components and has potential applications in biomedicine and bionanotechnology. Microtubules, nanoscopic tubular structures self-assembled from protein ... ...

    Abstract Abstract Pulsed electric field (PEF) technology is promising for the manipulation of biomolecular components and has potential applications in biomedicine and bionanotechnology. Microtubules, nanoscopic tubular structures self-assembled from protein tubulin, serve as important components in basic cellular processes as well as in engineered biomolecular nanosystems. Recent studies in cell-based models have demonstrated that PEF affects the cytoskeleton, including microtubules. However, the direct effects of PEF on microtubules are not clear. In this work, we developed a lab-on-a-chip platform integrated with a total internal reflection fluorescence microscope system to elucidate the PEF effects on a microtubules network mimicking the cell-like density of microtubules. The designed platform enables the delivery of short (microsecond-scale), high-field-strength ( $$\le$$ ≤ 25 kV/cm) electric pulses far from the electrode/electrolyte interface. We showed that microsecond PEF is capable of overcoming the non-covalent microtubule bonding force to the substrate and translocating the microtubules. This microsecond PEF effect combined with macromolecular crowding led to aggregation of microtubules. Our results expand the toolbox of bioelectronics technologies and electromagnetic tools for the manipulation of biomolecular nanoscopic systems and contribute to the understanding of microsecond PEF effects on a microtubule cytoskeleton.
    Keywords Medicine ; R ; Science ; Q
    Subject code 600
    Language English
    Publishing date 2022-02-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Anillin propels myosin-independent constriction of actin rings

    Ondřej Kučera / Valerie Siahaan / Daniel Janda / Sietske H. Dijkstra / Eliška Pilátová / Eva Zatecka / Stefan Diez / Marcus Braun / Zdenek Lansky

    Nature Communications, Vol 12, Iss 1, Pp 1-

    2021  Volume 12

    Abstract: Cytokinetic ring constriction during cell division requires actin but curiously is independent of myosin in many organisms. Here, the authors show that anillin, a protein enriched in the contractile ring, is a non-motor actin crosslinker that generates ... ...

    Abstract Cytokinetic ring constriction during cell division requires actin but curiously is independent of myosin in many organisms. Here, the authors show that anillin, a protein enriched in the contractile ring, is a non-motor actin crosslinker that generates contractile force in lieu of a molecular motor.
    Keywords Science ; Q
    Language English
    Publishing date 2021-07-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Fast photothermal spatial light modulation for quantitative phase imaging at the nanoscale

    Hadrien M. L. Robert / Kristýna Holanová / Łukasz Bujak / Milan Vala / Verena Henrichs / Zdeněk Lánský / Marek Piliarik

    Nature Communications, Vol 12, Iss 1, Pp 1-

    2021  Volume 10

    Abstract: Here, the authors present a high-speed photothermal spatial light modulator which can generate a step-like wavefront change without diffraction artifacts. They use this to perform quantitative phase imaging, capturing sub-millisecond motion with a ... ...

    Abstract Here, the authors present a high-speed photothermal spatial light modulator which can generate a step-like wavefront change without diffraction artifacts. They use this to perform quantitative phase imaging, capturing sub-millisecond motion with a nanometer resolution in 3D.
    Keywords Science ; Q
    Language English
    Publishing date 2021-05-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Mitochondria-adaptor TRAK1 promotes kinesin-1 driven transport in crowded environments

    Verena Henrichs / Lenka Grycova / Cyril Barinka / Zuzana Nahacka / Jiri Neuzil / Stefan Diez / Jakub Rohlena / Marcus Braun / Zdenek Lansky

    Nature Communications, Vol 11, Iss 1, Pp 1-

    2020  Volume 13

    Abstract: Intracellular trafficking of organelles is driven by kinesin-1 stepping along microtubules, but crowding conditions impede kinesin-1 motility. Here authors demonstrate that TRAK1, an adaptor protein essential for mitochondrial trafficking, activates ... ...

    Abstract Intracellular trafficking of organelles is driven by kinesin-1 stepping along microtubules, but crowding conditions impede kinesin-1 motility. Here authors demonstrate that TRAK1, an adaptor protein essential for mitochondrial trafficking, activates kinesin-1 and increases robustness of kinesin-1 stepping on crowded microtubule surfaces.
    Keywords Science ; Q
    Language English
    Publishing date 2020-06-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Diffusive tail anchorage determines velocity and force produced by kinesin-14 between crosslinked microtubules

    Annemarie Lüdecke / Anja-Maria Seidel / Marcus Braun / Zdenek Lansky / Stefan Diez

    Nature Communications, Vol 9, Iss 1, Pp 1-

    2018  Volume 9

    Abstract: Kinesin-14s, such as Ncd, interact with microtubules with their non-processive motor domains and their diffusive tail domains, but the influence of the tail domains on motor performance is not known. Here the authors show that tail domain slippage limits ...

    Abstract Kinesin-14s, such as Ncd, interact with microtubules with their non-processive motor domains and their diffusive tail domains, but the influence of the tail domains on motor performance is not known. Here the authors show that tail domain slippage limits the velocities and forces generated by Ncd, suggesting it acts as a slippery crosslinker.
    Keywords Science ; Q
    Language English
    Publishing date 2018-06-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Diffusive tail anchorage determines velocity and force produced by kinesin-14 between crosslinked microtubules

    Annemarie Lüdecke / Anja-Maria Seidel / Marcus Braun / Zdenek Lansky / Stefan Diez

    Nature Communications, Vol 9, Iss 1, Pp 1-

    2018  Volume 9

    Abstract: Kinesin-14s, such as Ncd, interact with microtubules with their non-processive motor domains and their diffusive tail domains, but the influence of the tail domains on motor performance is not known. Here the authors show that tail domain slippage limits ...

    Abstract Kinesin-14s, such as Ncd, interact with microtubules with their non-processive motor domains and their diffusive tail domains, but the influence of the tail domains on motor performance is not known. Here the authors show that tail domain slippage limits the velocities and forces generated by Ncd, suggesting it acts as a slippery crosslinker.
    Keywords Science ; Q
    Language English
    Publishing date 2018-06-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Integrative binding sites within intracellular termini of TRPV1 receptor.

    Lenka Grycova / Blanka Holendova / Ladislav Bumba / Jan Bily / Michaela Jirku / Zdenek Lansky / Jan Teisinger

    PLoS ONE, Vol 7, Iss 10, p e

    2012  Volume 48437

    Abstract: TRPV1 is a nonselective cation channel that integrates wide range of painful stimuli. It has been shown that its activity could be modulated by intracellular ligands PIP2 or calmodulin (CaM). The detailed localization and description of PIP2 interaction ... ...

    Abstract TRPV1 is a nonselective cation channel that integrates wide range of painful stimuli. It has been shown that its activity could be modulated by intracellular ligands PIP2 or calmodulin (CaM). The detailed localization and description of PIP2 interaction sites remain unclear. Here, we used synthesized peptides and purified fusion proteins of intracellular regions of TRPV1 expressed in E.coli in combination with fluorescence anisotropy and surface plasmon resonance measurements to characterize the PIP2 binding to TRPV1. We characterized one PIP2 binding site in TRPV1 N-terminal region, residues F189-V221, and two independent PIP2 binding sites in C-terminus: residues K688-K718 and L777-S820. Moreover we show that two regions, namely F189-V221 and L777-S820, overlap with previously localized CaM binding sites. For all the interactions the equilibrium dissociation constants were estimated. As the structural data regarding C-terminus of TRPV1 are lacking, restraint-based molecular modeling combined with ligand docking was performed providing us with structural insight to the TRPV1/PIP2 binding. Our experimental results are in excellent agreement with our in silico predictions.
    Keywords Medicine ; R ; Science ; Q
    Subject code 500
    Language English
    Publishing date 2012-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Human histone deacetylase 6 shows strong preference for tubulin dimers over assembled microtubules

    Lubica Skultetyova / Kseniya Ustinova / Zsofia Kutil / Zora Novakova / Jiri Pavlicek / Jana Mikesova / Dalibor Trapl / Petra Baranova / Barbora Havlinova / Martin Hubalek / Zdenek Lansky / Cyril Barinka

    Scientific Reports, Vol 7, Iss 1, Pp 1-

    2017  Volume 13

    Abstract: Abstract Human histone deacetylase 6 (HDAC6) is the major deacetylase responsible for removing the acetyl group from Lys40 of α-tubulin (αK40), which is located lumenally in polymerized microtubules. Here, we provide a detailed kinetic analysis of ... ...

    Abstract Abstract Human histone deacetylase 6 (HDAC6) is the major deacetylase responsible for removing the acetyl group from Lys40 of α-tubulin (αK40), which is located lumenally in polymerized microtubules. Here, we provide a detailed kinetic analysis of tubulin deacetylation and HDAC6/microtubule interactions using individual purified components. Our data unequivocally show that free tubulin dimers represent the preferred HDAC6 substrate, with a K M value of 0.23 µM and a deacetylation rate over 1,500-fold higher than that of assembled microtubules. We attribute the lower deacetylation rate of microtubules to both longitudinal and lateral lattice interactions within tubulin polymers. Using TIRF microscopy, we directly visualized stochastic binding of HDAC6 to assembled microtubules without any detectable preferential binding to microtubule tips. Likewise, indirect immunofluorescence microscopy revealed that microtubule deacetylation by HDAC6 is carried out stochastically along the whole microtubule length, rather than from the open extremities. Our data thus complement prior studies on tubulin acetylation and further strengthen the rationale for the correlation between tubulin acetylation and microtubule age.
    Keywords Medicine ; R ; Science ; Q
    Subject code 612
    Language English
    Publishing date 2017-09-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: The characterization of a novel S100A1 binding site in the N-terminus of TRPM1

    Jirku, Michaela / Jan Teisinger / Jiri Vondrasek / Kristyna Bousova / Ladislav Vyklicky / Lenka Monincova / Lucie Bednarova / Miroslav Sulc / Pavel Majer / Zdenek Lansky

    international journal of biochemistry & cell biology. 2016 Sept., v. 78

    2016  

    Abstract: Transient receptor potential melastatin-1 channel (TRPM1) is an important mediator of calcium influx into the cell that is expressed in melanoma and ON-bipolar cells. Similar to other members of the TRP channel family, the intracellular N- and C- ... ...

    Abstract Transient receptor potential melastatin-1 channel (TRPM1) is an important mediator of calcium influx into the cell that is expressed in melanoma and ON-bipolar cells. Similar to other members of the TRP channel family, the intracellular N- and C- terminal domains of TRPM1 are expected to play important roles in the modulation of TRPM1 receptor function. Among the most commonly occurring modulators of TRP channels are the cytoplasmically expressed calcium binding proteins calmodulin and S100 calcium-binding protein A1 (S100A1), but the interaction of TRPM1 with S100A1 has not been described yet. Here, using a combination of biophysical and bioinformatics methods, we have determined that the N-terminal L242-E344 region of TRPM1 is a S100A1 binding domain. We show that formation of the TRPM1/S100A1 complex is calcium-dependent. Moreover, our structural model of the complex explained data obtained from fluorescence spectroscopy measurements revealing that the complex formation is facilitated through interactions of clusters positively charged (K271A, R273A, R274A) and hydrophobic (L263A, V270A, L276A) residues at the N-terminus of TRPM1. Taken together, our data suggest a molecular mechanism for the potential regulation of TRPM1 by S100A1.
    Keywords binding sites ; bioinformatics ; calcium ; calmodulin ; fluorescence emission spectroscopy ; hydrophobicity ; melanoma ; models ; transient receptor potential channels
    Language English
    Dates of publication 2016-09
    Size p. 186-193.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 1228429-4
    ISSN 1878-5875 ; 1357-2725
    ISSN (online) 1878-5875
    ISSN 1357-2725
    DOI 10.1016/j.biocel.2016.07.014
    Database NAL-Catalogue (AGRICOLA)

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