Read by QxMD icon Read

Tethering complex

Luuk Kortekaas, Federico Lancia, Jorn D Steen, Wesley R Browne
The coupling of substituted carbazole compounds through carbon-carbon bond formation upon one-electron oxidation is shown to be a highly versatile approach to the formation of redox polymer films. Although the polymerization of single carbazole units has been proposed earlier, we show that by tethering pairs of carbazoles double sequential dimerization allows for facile formation of redox polymer films with fine control over film thickness. We show that the design of the monomers and in particular the bridging units is key to polymer formation, with the diaminobenzene motif proving advantageous, in terms of the matching to the redox potentials of the monomer and polymer film and thereby avoiding limitations in film thickness (autoinsulation), but introduces unacceptable instability due to the intrinsic redox activity of this moiety...
July 13, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
Wandi Zhu, Taylor L Voelker, Zoltan Varga, Angela R Schubert, Jeanne M Nerbonne, Jonathan R Silva
Voltage-gated Na(+) (NaV) channels comprise a macromolecular complex whose components tailor channel function. Key components are the non-covalently bound β1 and β3 subunits that regulate channel gating, expression, and pharmacology. Here, we probe the molecular basis of this regulation by applying voltage clamp fluorometry to measure how the β subunits affect the conformational dynamics of the cardiac NaV channel (NaV1.5) voltage-sensing domains (VSDs). The pore-forming NaV1.5 α subunit contains four domains (DI-DIV), each with a VSD...
July 18, 2017: Journal of General Physiology
Emre Lacin, Prafulla Aryal, Ian W Glaaser, Karthik Bodhinathan, Eric Tsai, Nidaa Marsh, Stephen J Tucker, Mark S P Sansom, Paul A Slesinger
G protein-gated inwardly rectifying potassium (GIRK) channels control neuronal excitability in the brain and are implicated in several different neurological diseases. The anionic phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) is an essential cofactor for GIRK channel gating, but the precise mechanism by which PIP2 opens GIRK channels remains poorly understood. Previous structural studies have revealed several highly conserved, positively charged residues in the "tether helix" (C-linker) that interact with the negatively charged PIP2 However, these crystal structures of neuronal GIRK channels in complex with PIP2 provide only snapshots of PIP2's interaction with the channel and thus lack details about the gating transitions triggered by PIP2 binding...
July 18, 2017: Journal of General Physiology
Debopam Datta, Ketaki Sarkar, Souvik Mukherjee, Xenia Meshik, Michael A Stroscio, Mitra Dutta
Quantum-dot (QD) based nanosensors are frequently used by researchers to detect small molecules, ions and different biomolecules. In this article, we present a sensor complex/system comprised of deoxyribonucleic acid (DNA) aptamer, gold nanoparticle and semiconductor QD, attached to a graphene oxide (GO) flake for detection of potassium. As reported herein, it is demonstrated that QD-aptamer-quencher nanosensor functions even when tethered to GO, opening the way to future applications where sensing can be accomplished simultaneously with other previously demonstrated applications of GO such as serving as a nanocarrier for drug delivery...
August 11, 2017: Nanotechnology
Xiaojie Zhang, Guanghui Wang, Chengdong Yang, Jun Huang, Xiaofeng Chen, Jie Zhou, Guangpu Li, Justice Norvienyeku, Zonghua Wang
The homotypic fusion and protein sorting protein complex (HOPS) is the first known tether complex identified in the endocytic system that plays a key role in promoting homotypic vacuolar fusion, vacuolar biogenesis and trafficking in a wide range of organisms, including plant and fungi. However, the exact influence of the HOPS complex on growth, reproduction and pathogenicity of the economically destructive rice blast fungus has not been investigated. In this study, we identified M. oryzae vacuolar protein sorting 41 (MoVps41) an accessory subunit of HOPS complex and used targeted gene deletion approach to evaluate its contribution to growth, reproduction and infectious life cycle of the rice blast fungus...
2017: Frontiers in Plant Science
Xiaoyun Tan, Juan Wei, Beibei Li, Mengru Wang, Yiqun Bao
Vacuoles are multiple functional and essential organelles in plants. Studies in Saccharomyces cerevisiae had identified a tethering factor HOPS (Homotypic Fusion and Vacuolar Protein Sorting) complex that plays a critical role in vacuole biogenesis. The HOPS complex consists of four core subunits (Vps11, Vps16, Vps18 and Vps33) and two special subunits (Vps39 and Vps41). All these subunits were found in Arabidopsis, and our knowledge of the function of Arabidopsis HOPS complex are still limited. In this study, we investigated the function of AtVps11 gene in Arabidopsis, we found that vps11/- lead to embryo lethal, vacuole biogenesis in embryo was impaired...
July 12, 2017: Biochemical and Biophysical Research Communications
Marie-Pierre Péli-Gulli, Serena Raucci, Zehan Hu, Jörn Dengjel, Claudio De Virgilio
Amino acids stimulate the eukaryotic target of rapamycin complex 1 (TORC1), and hence growth, through the Rag GTPases and their regulators. Among these, the yeast Lst4-Lst7 Rag GTPase GAP complex clusters, as we previously reported, at the vacuolar membrane upon amino acid starvation. In response to amino acid refeeding, it activates the Rag GTPase-TORC1 branch and is then dispersed from the vacuolar surface. Here, we show that the latter effect is driven by TORC1 itself, which directly phosphorylates several residues within the intra-DENN loop of Lst4 that, only in its non-phosphorylated state, tethers the Lst4-Lst7 complex to the vacuolar membrane...
July 11, 2017: Cell Reports
Jun Zhang, Pallavi Dubey, Akhil Padarti, Aileen Zhang, Rinkal Patel, Vipulkumar Patel, David Cistola, Ahmed Badr
BACKGROUND: Three NPXY motifs and one FERM domain in CCM1 makes it a versatile scaffold protein for tethering the signaling components together within the CCM signaling complex (CSC). The cellular role of CCM1 protein remains inadequately expounded. Both phosphotyrosine binding (PTB) and pleckstrin homology (pH) domains were recognized as structurally related but functionally distinct domains. METHODS: By utilizing molecular cloning, protein binding assays and RT-qPCR to identify novel cellular partners of CCM1 and its cellular expression patterns; by screening candidate PTB/PH proteins and subsequently structurally simulation in combining with current X-ray crystallography and NMR data to defined the essential structure of PTB/PH domain for NPXY-binding and the relationship among PTB, pH and FERM domain(s)...
July 8, 2017: Biochimica et Biophysica Acta
Nirmalya Bandyopadhyay, Pritha Basu, Gopinatha Suresh Kumar, Bhargab Guhathakurta, Pijush Singh, Jnan Prakash Naskar
A novel oxime based palladium(II) complex (1) has been synthesized out of the reaction of a Schiff base ligand, 1-phenyl-1-(pyridin-2-yl-hydrazono)-propan-2-one oxime (LH2) with Na2[PdCl4] in THF. Red and diamagnetic 1 has thoroughly been characterized by several analytical and spectroscopic means like CHN, ESI-MS, FAB-MS, FT-IR, (1)H NMR, (13)C NMR, UV-Vis and molar electrical conductivity measurements. Geometry optimizations at the level of DFT reveals that the Pd(II) centre in 1 is nested in a square-planar 'N3Cl' coordination environment...
July 1, 2017: Journal of Photochemistry and Photobiology. B, Biology
Saziye Yorulmaz Avsar, Joshua Alexander Jackman, Min Chul Kim, Bo Kyeong Yoon, Walter Hunziker, Nam-Joon Cho
The self-assembly formation of complement convertases - essential biomacromolecular complexes which amplify innate immune responses - is triggered by protein adsorption. Herein, a supported lipid bilayer platform was utilized in order to investigate the effects of covalent and noncovalent tethering strategies on the self-assembly of alternative pathway C3 convertase components, starting with C3b protein adsorption followed by addition of factors B and D. Quartz crystal microbalance-dissipation (QCM-D) experiments measured the real-time kinetics of convertase assembly onto supported lipid bilayers...
July 6, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Yoshihiko Yamamoto, Yuta Okude, Shota Mori, Masatoshi Shibuya
Cycloaddition reactions of 1,6-diynes bearing methyl terminal groups with p-anisaldehyde were conducted using a cationic ruthenium catalyst with a η(5)-pentamethylcyclopentadienyl ligand in THF at room temperature to afford dienyl ketones via ring opening of the initially formed fused pyrans. (Z)-Stereoisomers of dienyl ketones were selectively obtained using the ruthenium catalyst, whereas previously reported rhodium catalysts produced (E)-isomers. These (E)- and (Z)-selectivities are kinetically controlled as the control experiments showed that the E/Z-isomerization of (E)-dienylketone occurs at 70 °C for 10 h to afford an E/Z-ratio of almost 1:1...
July 14, 2017: Journal of Organic Chemistry
Martin W Goldberg
No abstract text is available yet for this article.
July 1, 2017: Seminars in Cell & Developmental Biology
Nicola Salvarese, Fiorenzo Refosco, Roberta Seraglia, Marco Roverso, Alessandro Dolmella, Cristina Bolzati
The synthesis and characterization of a new series of neutral, six-coordinated compounds [Re(III)X3(PNPR)], where X is Cl or Br and PNPR is a diphosphinoamine having the general formula (Ph2PCH2CH2)2NR (R = H, CH3, CH2CH3, CH2CH2CH3, CH2CH2CH2CH3 and CH2CH2OCH3) are reported. Stable [Re(III)X3(PNPR)] complexes were synthesized, in variable yields, starting from precursors where the metal was in different oxidation states (iii and v), by ligand-exchange and/or redox-substitution reactions. The compounds were characterized by elemental analysis, proton NMR spectroscopy, cyclic voltammetry, UV/vis spectroscopy, positive-ion electrospray ionization mass spectrometry (ESI(+)-MS) and X-ray diffraction analysis...
July 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Thomas Heimerl, Jennifer Flechsler, Carolin Pickl, Veronika Heinz, Benjamin Salecker, Josef Zweck, Gerhard Wanner, Stefan Geimer, Rachel Y Samson, Stephen D Bell, Harald Huber, Reinhard Wirth, Louie Wurch, Mircea Podar, Reinhard Rachel
Based on serial sectioning, focused ion beam scanning electron microscopy (FIB/SEM), and electron tomography, we depict in detail the highly unusual anatomy of the marine hyperthermophilic crenarchaeon, Ignicoccus hospitalis. Our data support a complex and dynamic endomembrane system consisting of cytoplasmic protrusions, and with secretory function. Moreover, we reveal that the cytoplasm of the putative archaeal ectoparasite Nanoarchaeum equitans can get in direct contact with this endomembrane system, complementing and explaining recent proteomic, transcriptomic and metabolomic data on this inter-archaeal relationship...
2017: Frontiers in Microbiology
Bastijn J G van den Boom, Pavlina Pavlidi, Casper J H Wolf, Adriana H Mooij, Ingo Willuhn
BACKGROUND: Manual analysis of behavior is labor intensive and subject to inter-rater variability. Although considerable progress in automation of analysis has been made, complex behavior such as grooming still lacks satisfactory automated quantification. NEW METHOD: We trained a freely available, automated classifier, Janelia Automatic Animal Behavior Annotator (JAABA), to quantify self-grooming duration and number of bouts based on video recordings of SAPAP3 knockout mice (a mouse line that self-grooms excessively) and wild-type animals...
June 23, 2017: Journal of Neuroscience Methods
Jingchao Wu, Anna Akhmanova
The organization of microtubule networks is crucial for controlling chromosome segregation during cell division, positioning, and transport of different organelles and for cell polarity and morphogenesis. The geometry of microtubule arrays strongly depends on the localization and activity of the sites where microtubules are nucleated and where their minus ends are anchored. Such sites are often clustered into structures known as microtubule-organizing centers, which include the centrosomes in animals and spindle pole bodies in fungi...
June 23, 2017: Annual Review of Cell and Developmental Biology
Christine A Henderson, Christopher G Gomez, Stefanie M Novak, Lei Mi-Mi, Carol C Gregorio
Cardiac and skeletal striated muscles are intricately designed machines responsible for muscle contraction. Coordination of the basic contractile unit, the sarcomere, and the complex cytoskeletal networks are critical for contractile activity. The sarcomere is comprised of precisely organized individual filament systems that include thin (actin), thick (myosin), titin, and nebulin. Connecting the sarcomere to other organelles (e.g., mitochondria and nucleus) and serving as the scaffold to maintain cellular integrity are the intermediate filaments...
June 18, 2017: Comprehensive Physiology
Yong Xue, Stefan Schmollinger, Narsis Attar, Oscar Campos, Maria Vogelauer, Michael F Carey, Sabeeha S Merchant, Siavash K Kurdistani
The Endoplasmic Reticulum-Mitochondria Encounter Structure (ERMES) is a protein complex that physically tethers the two organelles to each other and creates the physical basis for communication between them. ERMES functions in lipid and calcium exchange between the ER and mitochondria, protein import into mitochondria and maintenance of mitochondrial morphology and genome. Here we report that ERMES is also required for iron homeostasis. Loss of ERMES components activates an Aft1-dependent iron deficiency response even in iron-replete conditions, leading to accumulation of excess iron inside the cell...
June 21, 2017: Journal of Biological Chemistry
Hongki Song, William Wickner
While SNARE heptad-repeats are well studied, SNAREs also have upstream N-domains of indeterminate function. The assembly of yeast vacuolar SNAREs into complexes for fusion can be studied in chemically-defined reactions. Complementary proteoliposomes bearing a Rab:GTP and either the vacuolar R-SNARE or one of the 3 integrally-anchored Q-SNAREs were incubated with the tethering/SM protein complex HOPS and the two other soluble SNAREs (lacking a trans-membrane anchor) or their SNARE heptad-repeat domains. Fusion required a trans-membrane anchored R-SNARE on one membrane and an anchored Q-SNARE on the other...
June 21, 2017: Molecular Biology of the Cell
Eduardo Victor Peris, Susana Ibañez, Macarena Poyatos
A combination of self-complementary pi-pi-stacking interactions and metallophilic interactions triggers the self-assembly of a new di-gold(I) metallotweezer in the presence of several M+ ions. Titrations by fluorescence spectroscopy allowed determining the association constants of the resulting inclusion duplex complexes. The quasi-orthogonal disposition of the polycyclic aromatic hydrocarbons at the tether (anthracene), and at the NHC ligand (pyrene), together with the presence of the Au(I) centers, affords the self-complementarity needed for the formation of self-assembled structures with a cavity capable of recognizing metal cations and establishing M-Au metallophilic interactions...
June 19, 2017: Angewandte Chemie
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"