How proteins are transported into mitochondria

Most mitochondrial polypeptides are synthesized outside the organelle as precursors which are usually larger than the ‘mature’ polypeptides found within mitochondria. The precursors are imported into the mitochondria by a process which is independent of protein synthesis but dependent on high-energy phosphate bonds inside the mitochondria. This mechanism is basically different from that which governs the movement of secretory polypeptides across the membrane of the endoplasmic reticulum

Dephosphorylation of the focal adhesion protein VASP in vitro and in intact human platelets

AbstractThe focal adhesion protein VASP, a possible link between signal transduction pathways and the microfilament system, is phosphorylated by both cAMP- and cGMP-dependent protein kinases in vitro and in intact cells. Here, the analysis of VASP dephosphorylation by the serine/threonine protein phosphatases (PP) PP1, PP2A, PP2B and PP2C in vitro is reported. The phosphatases differed in their selectivity with respect to the dephosphorylation of individual VASP phosphorylation sites. Incubation of human platelets with okadaic acid, a potent inhibitor of PP1 and PP2A, caused the accumulation of phosphorylated VASP indicating that the phosphorylation status of VASP in intact cells is regulated to a major extent by serine/ threonine protein phosphatases. Furthermore, the accumulation of phosphorylated cAMP-dependent protein kinase substrate(s) appears to account for inhibitory effects of okadaic acid on platelet function

Site-selective tagging of proteins by pnictogen-mediated self-assembly

Site-selective chemical protein modification is achieved by self-assembly of a specific di-cysteine motif, trivalent pnictogens (As, Sb or Bi) and an aromatic mercaptomethyl-based probe. The strategy is demonstrated with a quaternary complex involving Zika virus protease and a lanthanide ion, enabling paramagnetic nuclear magnetic resonance spectroscopy and luminescence measurements.Financial support by the Australian Research Council is gratefully acknowledge

Trimethylsilyl tag for probing protein-ligand interactions by NMR

Protein-ligand titrations can readily be monitored with a trimethylsilyl (TMS) tag. Owing to the intensity, narrow line shape and unique chemical shift of a TMS group, dissociation constants can be determined from straightforward 1D 1H-NMR spectra not only in the fast but also in the slow exchange limit. The tag is easily attached to cysteine residues and a sensitive reporter of ligand binding also at sites where it does not interfere with ligand binding or catalytic efficiency of the target protein. Its utility is demonstrated for the Zika virus NS2B-NS3 protease and the human prolyl isomerase FK506 binding protein.C.N. and G.O. thank the Alexander von Humboldt Foundation for a Feodor Lynen Fellowship and the Australian Research Council for a Laureate Fellowship, respectively. Financial project support by the Australian Research Council, the Austrian Science Fund (FWF) (DK Molecular Enzymology W901 to K.Z.) and by NAWI Graz is gratefully acknowledged

Antología de la Guía de Maimónides por Leibniz

La traducción al latín de la obra de Maimónides Moreh Nevukhim | Guía para Perplejos, ha sido la obra judía más influyente en los últimos milenios (Di Segni, 2019; Rubio, 2006; Wohlman, 1988, 1995; Kohler, 2017). Ésta marcó el comienzo de la escolástica, «hija del judaísmo nutrida por pensadores judíos, » según el historiador Heinrich Graetz (Geschichte der Juden, L. 6, Leipzig 1861, p. xii). Impresa por la primera imprenta mecánica de Gutenberg, su influencia en Occidente se extendió hasta el Quinto Concilio de Letrán (1512-1517) « donde se instó a los eruditos a eliminar las dificultades que parecían dividir el conjunto de la teología y la filosofía (Leibniz, Teodicea, 11 ). » Durante siglos, la Guía revolucionó el currículo de estudios de la instrucción escolar al reintegrar en el ámbito de la fe las leyes del pensamiento (la cuarta de las cuales se convirtió en el principio de la razón suficiente de Leibniz). La colección completa de las notas que exponen las ideas de la Guía incluye todos los pasajes seleccionados y reescritos por Leibniz. Esta primera traducción bilingüe completa y anotada de los manuscritos originales en latín sirve como una puerta de entrada a la fe conforme a la Razón. « El excelente libro del rabino Moisés Maimónides, Guía para perplejos, es más filosófico de lo que había imaginado y merece una lectura atenta. El autor, distinguido por su inteligencia filosófica, fue versado en matemáticas, en el arte de la medicina, y también en el conocimiento de las Sagradas Escrituras. » — GW LEIBNIZ, 1685. Antología de Leibniz de la Guía de Maimónides, Capítulo III

Anthologie du Guide de Maïmonide par Leibniz

La traduction latine du livre de Maïmonide Moreh Nevukhim | Guide des égarés, a été l'ouvrage juif le plus influent des derniers millénaires (Di Segni, 2019 ; Rubio, 2006 ; Wohlman, 1988, 1995 ; Kohler, 2017). Elle marqua le début de la scolastique, fille du judaïsme élevée par des penseurs juifs, selon l'historien Heinrich Graetz (Geschichte der Juden, L. 6, Leipzig 1861, p. xii). Imprimée par la première presse mécanique de Gutenberg, son influence en Occident s'étendit jusqu'au Vème concile du Latran (1512-1517) « où les savants furent encouragés à lever les difficultés qui semblaient diviser l'ensemble de la théologie et de la philosophie — (Leibniz, Théodicée, 11 ) ». Pendant des siècles, le Guide a révolutionné le programme d'instruction scolaire en réintégrant dans le domaine de la foi les lois de la pensée (dont la quatrième est devenue le principe de la raison suffisante de Leibniz). Cette collection complète de notes qui expose les idées du Guide fournit tous les passages sélectionnés et réécrits par Leibniz. Cette première traduction complète bilingue annotée des manuscrits originaux en latin sert de porte d'entrée à la foi conforme à la Raison. « L'excellent livre du Rabbin Moïse Maïmonide, le Guide des égarés, est plus philosophique que je ne l'avais imaginé et mérite une lecture attentive. L'auteur, distingué par son intelligence en philosophie, était versé dans les mathématiques, l'art médical, et aussi dans la connaissance de Saintes Écritures. » — G. W. LEIBNIZ, 1685, Anthologie de Leibniz du Guide de Maïmonide, Chapitre III

Uniform nomenclature for the protein transport machinery of the mitochondrial membranes

[no abstract avaiable

Frazeologijos samprata XVIII a. lituanistikos šaltiniuose

[full article and abstract in Lithuanian; abstract in English] This article addresses the problem of the concepts phraseologism and phraseology in modern linguistic literature. It analyses the history of the concepts phraseologism and phraseology in the Lituanistic sources of Prussian Lithuania (Lithuania Minor) of 18th century and strives to justify the need to use these terms in their broad rather than narrow sense. The terms phraseology and phraseologism are not used in any Lituanistic sources of the 18th century. The Latin term idiotismus, used in the early 18th century philological polemic sources, such as Michael Mörlin’s, Johann Schultz’s and Jacob Perkuhn’s works, is not clearly defined. It could be understood either as (1) a peculiar saying or a figurative expression (i.e., a stable word combination or sentence) or (2) a case of common usage, a language norm recognized by society. The Latin terms Idiotismus, Phrase, Phraseologie, used in the German linguistic literature of the 17th–18th centuries, are not clearly defined either. Due to the lack of clear definitions of the concepts phraseologism and phraseology in the Lituanistic sources of the 18th century and in the 18th century German linguistic literature, it would be appropriate to use the terms phraseologism and phraseology in their broad rather than narrow sense, i.e., to regard the stability of not only a word combination but also of a sentence as a distinctive feature of a phraseologism without emphasizing figurativeness or idiomaticity. The suggested definition would be as follows: a phraseologism is a stable word combination or sentence. The researchers of old Lituanistic sources need the broad definition for two more reasons. First, in the old dictionaries, ethnographic works, and collections of small folklore genres, stable word combinations and sayings were recorded without selection; as they were presented together as specific linguistic facts of some regional variety, they should be analysed as wholes. Second, these combinations and sayings should also be taken as wholes in the analysis of the speech community that used them – phraseologisms, in the broad sense, can be treated as (re)constructive instruments of social and cultural identity, i.e., the analysis of phraseologisms could be used to recognize the mechanism defining the boundaries of identity and to reconstruct the content of social and cultural life.  [straipsnis ir santrauka lietuvių kalba; santrauka anglų kalba] Straipsnyje apta riama frazeologizmo ir frazeologijos sampratos šiuolaikinėje lingvistinėje literatūroje problema. Remiantis XVIII a. Prūsijos Lietuvos lituanistikos šaltiniais, analizuojama frazeologizmo ir frazeologijos sampratos istorija, siekiama pagrįsti būtinybę dabartiniuose senųjų raštų tyrimuose minėtus terminus vartoti plačiąja, o ne siaurąja prasme

On the Scales of Photographic Abstraction

This article explores three key ways in which questions of abstraction have been and continue to be closely associated with photography: the tradition of photographs that desire to “be” abstract; the invisible but determining forms of abstraction central to capitalism and shaping of photography as a technical-historical form; and the technical-conceptual abstractions embedded in and structuring of photographic apparatuses. The exploration of these themes is pursued through analysis of Vilém Flusser’s philosophy of photography, Lambert Wiesing’s analysis of abstract photography and Allan Sekula’s critique of capitalist modes of equivalence and exchange as these impact on the photographic. These analyses are pursued through exploration of the issues, processes and operations of “scale”, “scaling” and “scalability” entailed in these three modes of abstraction and in their critical and theoretical reflection. The aim of this strategy is to outline and to analyse the complex web of abstractions that are central to photography and the modes of scale that are crucial to abstraction in this context. The article suggests that to encounter or to think about abstraction photographically is to operate within some modulation of scale and that this may in fact be the closest one can get to envisioning the complexity of abstraction in the photographic context