Pufendorf, Samuel

During the last two decades, Samuel von Pufendorf’s (1632–1694) natural law philosophy has become the subject of renewed and growing attentiveness among intellectual historians and philosophers (Seidler 2015). In the late-seventeenth century and early eighteenth century, Pufendorf was the most widely-read moral and political philosopher in Europe, whose reputation is most clearly exemplified in the impressive number of translations and editions of his works. Pufendorfian natural law theory offered a shared vocabulary and conceptual possibilities for the discussion of morality, politics and interstate relations for numerous eighteenth-century thinkers, such as Christian Thomasius, the authors of the Scottish Enlightenment and Jean-Jacques Rousseau. Pufendorf spent large parts of his career in princely courts and portrayed the history of states and their natural law foundations in his widely circulated historical works (Seidler 1997). Moreover, he also wrote on the issues of theology and church-state relations (Döring 1992, Zurbuchen 1998).Peer reviewe

The SWISS-2DPAGE database: what has changed during the last year

Swiss-2DPAGE (http://www.expasy.ch/ch2d/) is an annotated two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) database established in 1993. The current release contains 21 reference maps from human and mouse biological samples, as well as from Saccharomyces cerevisiae, Escherichia coli and Dictyostelium discoideum origin. These reference maps now have 2480 identified spots, corresponding to 528 separate protein entries in the database, in addition to virtual entries for each SWISS-PROT sequence. During the last year, the SWISS-2DPAGE has undergone major changes. Six new maps have been added, and new functions to access the data have been provided through the ExPASy server. Finally, an important change concerns the database funding sourc

Spin polarization of the L-gap surface states on Au(111)

The electron spin polarization (ESP) of the L-gap surface states on Au(111) is investigated theoretically by means of first-principles electronic-structure and photoemission calculations. The surface states show a large spin-orbit induced in-plane ESP which is perpendicular to the in-plane wavevector, in close analogy to a two-dimensional electron gas with Rashba spin-orbit interaction. The surface corrugation leads to a small ESP component normal to the surface, being not reported so far. The surface-states ESP can be probed qualitatively and quantitatively by spin- and angle-resolved photoelectron spectroscopy, provided that the initial-state ESP is retained in the photoemission process and not obscured by spin-orbit induced polarization effects. Relativistic photoemission calculations provide detailed information on what photoemission set-ups allow to conclude from the photoelectron ESP on that of the surface states.Comment: 22 pages with 8 figure

Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel β-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein vibrational spectroscopy. 2D IR correlation spectra of the amide I region of poly-L-lysine, concanavalin A, ribonuclease A, and lysozyme show cross-peaks between the IR-active transitions that are characteristic of amide I couplings for polypeptides in antiparallel hydrogen-bonding registry. For poly-L-lysine, the 2D IR spectrum contains the eight-peak structure expected for two dominant vibrations of an extended, ordered antiparallel β-sheet. In the proteins with antiparallel β-sheets, interference effects between the diagonal and cross-peaks arising from the sheets, combined with diagonally elongated resonances from additional amide transitions, lead to a characteristic “Z”-shaped pattern for the amide I region in the 2D IR spectrum. We discuss in detail how the number of strands in the sheet, the local configurational disorder in the sheet, the delocalization of the vibrational excitation, and the angle between transition dipole moments affect the position, splitting, amplitude, and line shape of the cross-peaks and diagonal peaks.

Inefficient Quality Control of Thermosensitive Proteins on the Plasma Membrane

BACKGROUND: Misfolded proteins are generally recognised by cellular quality control machinery, which typically results in their ubiquitination and degradation. For soluble cytoplasmic proteins, degradation is mediated by the proteasome. Membrane proteins that fail to fold correctly are subject to ER associated degradation (ERAD), which involves their extraction from the membrane and subsequent proteasome-dependent destruction. Proteins with abnormal transmembrane domains can also be recognised in the Golgi or endosomal system and targeted for destruction in the vacuole/lysosome. It is much less clear what happens to membrane proteins that reach their destination, such as the cell surface, and then suffer damage. METHODOLOGY/PRINCIPAL FINDINGS: We have tested the ability of yeast cells to degrade membrane proteins to which temperature-sensitive cytoplasmic alleles of the Ura3 protein or of phage lambda repressor have been fused. In soluble form, these proteins are rapidly degraded upon temperature shift, in part due to the action of the Doa10 and San1 ubiquitin ligases and the proteasome. When tethered to the ER protein Use1, they are also degraded. However, when tethered to a plasma membrane protein such as Sso1 they escape degradation, either in the vacuole or by the proteasome. CONCLUSIONS/SIGNIFICANCE: Membrane proteins with a misfolded cytoplasmic domain appear not to be efficiently recognised and degraded once they have escaped the ER, even though their defective domains are exposed to the cytoplasm and potentially to cytoplasmic quality controls. Membrane tethering may provide a way to reduce degradation of unstable proteins

Functional Diversity and Structural Disorder in the Human Ubiquitination Pathway

The ubiquitin-proteasome system plays a central role in cellular regulation and protein quality control (PQC). The system is built as a pyramid of increasing complexity, with two E1 (ubiquitin activating), few dozen E2 (ubiquitin conjugating) and several hundred E3 (ubiquitin ligase) enzymes. By collecting and analyzing E3 sequences from the KEGG BRITE database and literature, we assembled a coherent dataset of 563 human E3s and analyzed their various physical features. We found an increase in structural disorder of the system with multiple disorder predictors (IUPred - E1: 5.97%, E2: 17.74%, E3: 20.03%). E3s that can bind E2 and substrate simultaneously (single subunit E3, ssE3) have significantly higher disorder (22.98%) than E3s in which E2 binding (multi RING-finger, mRF, 0.62%), scaffolding (6.01%) and substrate binding (adaptor/substrate recognition subunits, 17.33%) functions are separated. In ssE3s, the disorder was localized in the substrate/adaptor binding domains, whereas the E2-binding RING/HECT-domains were structured. To demonstrate the involvement of disorder in E3 function, we applied normal modes and molecular dynamics analyses to show how a disordered and highly flexible linker in human CBL (an E3 that acts as a regulator of several tyrosine kinase-mediated signalling pathways) facilitates long-range conformational changes bringing substrate and E2-binding domains towards each other and thus assisting in ubiquitin transfer. E3s with multiple interaction partners (as evidenced by data in STRING) also possess elevated levels of disorder (hubs, 22.90% vs. non-hubs, 18.36%). Furthermore, a search in PDB uncovered 21 distinct human E3 interactions, in 7 of which the disordered region of E3s undergoes induced folding (or mutual induced folding) in the presence of the partner. In conclusion, our data highlights the primary role of structural disorder in the functions of E3 ligases that manifests itself in the substrate/adaptor binding functions as well as the mechanism of ubiquitin transfer by long-range conformational transitions. © 2013 Bhowmick et al

Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers

Functional Reconstitution of a Tunable E3-Dependent Sumoylation Pathway in Escherichia coli

SUMO (small ubiquitin-related modifier) is a reversible post-translational protein modifier that alters the localization, activity, or stability of proteins to which it is attached. Many enzymes participate in regulated SUMO-conjugation and SUMO-deconjugation pathways. Hundreds of SUMO targets are currently known, with the majority being nuclear proteins. However, the dynamic and reversible nature of this modification and the large number of natively sumoylated proteins in eukaryotic proteomes makes molecular dissection of sumoylation in eukaryotic cells challenging. Here, we have reconstituted a complete mammalian SUMO-conjugation cascade in Escherichia coli cells that involves a functional SUMO E3 ligase, which effectively biases the sumoylation of both native and engineered substrate proteins. Our sumo-engineered E. coli cells have several advantages including efficient protein conjugation and physiologically relevant sumoylation patterns. Overall, this system provides a rapid and controllable platform for studying the enzymology of the entire sumoylation cascade directly in living cells

Ubiquitin Fold Modifier 1 (UFM1) and Its Target UFBP1 Protect Pancreatic Beta Cells from ER Stress-Induced Apoptosis

UFM1 is a member of the ubiquitin like protein family. While the enzymatic cascade of UFM1 conjugation has been elucidated in recent years, the biological function remains largely unknown. In this report we demonstrate that the recently identified C20orf116 [1], which we name UFM1-binding protein 1 containing a PCI domain (UFBP1), andCDK5RAP3 interact with UFM1. Components of the UFM1 conjugation pathway (UFM1, UFBP1, UFL1 and CDK5RAP3) are highly expressed in pancreatic islets of Langerhans and some other secretory tissues. Co-localization of UFM1 with UFBP1 in the endoplasmic reticulum (ER)depends on UFBP1. We demonstrate that ER stress, which is common in secretory cells, induces expression of Ufm1, Ufbp1 and Ufl1 in the beta-cell line INS-1E.siRNA-mediated Ufm1 or Ufbp1knockdown enhances apoptosis upon ER stress.Silencing the E3 enzyme UFL1, results in similar outcomes, suggesting that UFM1-UFBP1 conjugation is required to prevent ER stress-induced apoptosis. Together, our data suggest that UFM1-UFBP1participate in preventing ER stress-induced apoptosis in protein secretory cells