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101.
Jörg Votteler Elena Iavnilovitch Orit Fingrut Vivian Shemesh Daniel Taglicht Omri Erez Stefan Sörgel Torsten Walther Norbert Bannert Ulrich Schubert Yuval Reiss 《BMC biochemistry》2009,10(1):1-14
Background
The ALG2-interacting protein X (ALIX)/AIP1 is an adaptor protein with multiple functions in intracellular protein trafficking that plays a central role in the biogenesis of enveloped viruses. The ubiquitin E3-ligase POSH (plenty of SH3) augments HIV-1 egress by facilitating the transport of Gag to the cell membrane. Recently, it was reported, that POSH interacts with ALIX and thereby enhances ALIX mediated phenotypes in Drosophila.Results
In this study we identified ALIX as a POSH ubiquitination substrate in human cells: POSH induces the ubiquitination of ALIX that is modified on several lysine residues in vivo and in vitro. This ubiquitination does not destabilize ALIX, suggesting a regulatory function. As it is well established that ALIX rescues virus release of L-domain mutant HIV-1, HIV-1ΔPTAP, we demonstrated that wild type POSH, but not an ubiquitination inactive RING finger mutant (POSHV14A), substantially enhances ALIX-mediated release of infectious virions derived from HIV-1ΔPTAP L-domain mutant (YPXnL-dependent HIV-1). In further agreement with the idea of a cooperative function of POSH and ALIX, mutating the YPXnL-ALIX binding site in Gag completely abrogated augmentation of virus release by overexpression of POSH. However, the effect of the POSH-mediated ubiquitination appears to be auxiliary, but not necessary, as silencing of POSH by RNAi does not disturb ALIX-augmentation of virus release.Conclusion
Thus, the cumulative results identified ALIX as an ubiquitination substrate of POSH and indicate that POSH and ALIX cooperate to facilitate efficient virus release. However, while ALIX is obligatory for the release of YPXnL-dependent HIV-1, POSH, albeit rate-limiting, may be functionally interchangeable. 相似文献102.
Mo Sun Jie Deng Andreas Walther 《Angewandte Chemie (International ed. in English)》2020,59(41):18161-18165
Adaptivity is an essential trait of life. One type of adaptivity is the reconfiguration of a functional system states by correlating sensory inputs. We report polymer transformers, which can adaptively reconfigure their composition from a state of a mixed copolymer to being enriched in either monomer A or B. This is achieved by embedding and hierarchically interconnecting two chemically fueled activation/deactivation enzymatic reaction networks for both monomers via a joint activation pathway (network level) and an AB linker monomer reactive to both A and B (species level). The ratio of enzymes governing the individual deactivation pathways (our external signals) control the enrichment behavior in the dynamic state. The method shows high programmability of the reconfigured state, rejuvenation of transformation cycles, and quick in situ adaptation. As a proof‐of‐concept, we showcase this dynamic reconfiguration for colloidal surface functionalities. 相似文献
103.
The notion of a separating time for a pair of measures on a filtered space is helpful for studying problems of (local) absolute continuity and singularity of measures. In this paper, we describe a certain canonical setting for continuous local martingales (abbreviated below as CLMs) and find an explicit form of separating times for CLMs in this setting. 相似文献
104.
Walther Burstyn 《Fresenius' Journal of Analytical Chemistry》1902,41(8):501-502
Ohne Zusammenfassung 相似文献
105.
Müllner M Yuan J Weiss S Walther A Förtsch M Drechsler M Müller AH 《Journal of the American Chemical Society》2010,132(46):16587-16592
We report the preparation of water-soluble organo-silica hybrid nanotubes templated by core-shell-corona structured triblock terpolymer cylindrical polymer brushes (CPBs). The CPBs consist of a polymethacrylate backbone, a poly(tert-butyl acrylate) (PtBA) core, a poly(3-(trimethoxysilyl)propyl acrylate) (PAPTS) shell, and a poly(oligo(ethylene glycol) methacrylate) (POEGMA) corona. They were prepared via the "grafting from" strategy by the combination of two living/controlled polymerization techniques: anionic polymerization for the backbone and atom transfer radical polymerization (ATRP) for the triblock terpolymer side chains. The monomers tBA, APTS, and OEGMA were consecutively grown from the pendant ATRP initiating groups along the backbone to spatially organize the silica precursor, the trimethoxysilyl groups, into a tubular manner. The synthesized core-shell-corona structured CPBs then served as a unimolecular cylindrical template for the in situ fabrication of water-soluble organo-silica hybrid nanotubes via base-catalyzed condensation of the PAPTS shell block. The formed tubular nanostructures were characterized by transmission electron microscopy (TEM), cryogenic TEM, and atomic force microscopy. 相似文献
106.
Markus Walther Bernd M. Fischer Alex Ortner Andreas Bitzer Andreas Thoman Hanspeter Helm 《Analytical and bioanalytical chemistry》2010,397(3):1009-1017
Over the past decade, terahertz spectroscopy has evolved into a versatile tool for chemically selective sensing and imaging
applications. In particular, the potential to coherently generate and detect short, and hence, broadband terahertz pulses
led to the development of efficient and compact spectrometers for this interesting part of the electromagnetic spectrum, where
common packaging materials are transparent and many chemical compounds show characteristic absorptions. Although early proof-of-principle
demonstrations have shown the great potential of terahertz spectroscopy for sensing and imaging, the technology still often
lacks the required sensitivity and suffers from its intrinsically poor spatial resolution. In this review we discuss the current
potential of terahertz pulse spectroscopy and highlight recent technological advances geared towards both enhancing spectral
sensitivity and increasing spatial resolution. 相似文献
107.
Hans-Otto Walther 《Journal of Mathematical Sciences》2014,202(6):911-933
We consider nonautonomous retarded functional differential equations under hypotheses which are designed for the application to equations with variable time lags, which may be unbounded, and construct an evolution system of solution operators which are continuously differentiable. These operators are defined on manifolds of continuously differentiable functions. The results apply to pantograph equations and to nonlinear Volterra integro-differential equations, for example. For linear equations we also provide a simpler evolution system with solution operators on a Banach space of continuous functions. 相似文献
108.
We present the adaptation and implementation of a composite-step trust region algorithm, developed in (Walther, SIAM J. Optim. 19(1):307–325, 2008), that incorporates the approximation of the Jacobian of the equality constraints with a specialized quasi-Newton method. The forming and/or factoring of the exact Jacobian in each optimization step is avoided. Hence, the presented approach is especially well suited for equality constrained optimization problems where the Jacobian of the constraints is dense. 相似文献
109.
110.
E. Kapon M. Walther J. Christen M. Grundmann C. Caneau D.M. Hwang E. Colas R. Bhat G.H. Song D. Bimberg 《Superlattices and Microstructures》1992,12(4)
Quantum wire (QWR) heterostructures suitable for optoelectronic applications should meet a number of requirements, including defect free interfaces, large subband separation, long carrier lifetime, efficient carrier capture. The structural and opticl properties of GaAs/AlGaAs and InGaAs/GaAs quantum wire (QWR) heterostructures grown by organometallic chemical vapor deposition on nonplanr substrates, which satisfy many of these criteria, are described. These crescent-shaped QWRs are formed in situ during epitaxial growth resulting in virtually defect free interfaces. Effective wire widths as small as 10nm have been achieved, corresponding to electron subband separations greater than KBT at room temperature. The enhanced density of states at the QWR subbands manifests itself in higher optical absorption and emission as visualized in photoluminescence (PL), PL excitation, amplified spontaneous emission and lasing spectra of these structures. Effective carrier capture into the wires via connected quantum well regions, which is important for enhancing the otherwise extremely small capture cross section of these wires, has also been observed. Room temperature operation of GaAs/AlGaAs and strained InGaAs/GaAs QWR lasers with threshold currents as low as 0.6mA has been demonstrated. 相似文献