scholarly journals Intramembrane Proteolysis of Signal Peptides: An Essential Step in the Generation of HLA-E Epitopes

2001 ◽  
Vol 167 (11) ◽  
pp. 6441-6446 ◽  
Author(s):  
Marius K. Lemberg ◽  
Felicity A. Bland ◽  
Andreas Weihofen ◽  
Veronique M. Braud ◽  
Bruno Martoglio
Keyword(s):  
Signal Peptides ◽  
Intramembrane Proteolysis ◽  
Essential Step

Intramembrane proteolysis and post-targeting functions of signal peptides

2003 ◽  
Vol 31 (6) ◽  
pp. 1243-1247 ◽  
Author(s):  
B. Martoglio
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Bilayer ◽  
Signal Peptide ◽  
Eukaryotic Cells ◽  
Endoplasmic Reticulum Membrane ◽  
Signal Peptides ◽  
Peptide Fragments ◽  
Intramembrane Proteolysis ◽  
Signal Sequences ◽  
Membrane Spanning

Signal sequences are the addresses of proteins destined for secretion. In eukaryotic cells, they mediate targeting to the endoplasmic reticulum membrane and insertion into the translocon. Thereafter, signal sequences are cleaved from the pre-protein and liberated into the endoplasmic reticulum membrane. We have recently reported that some liberated signal peptides are further processed by the intramembrane-cleaving aspartic protease signal peptide peptidase. Cleavage in the membrane-spanning portion of the signal peptide promotes the release of signal peptide fragments from the lipid bilayer. Typical processes that include intramembrane proteolysis is the regulatory or signalling function of cleavage products. Likewise, signal peptide fragments liberated upon intramembrane cleavage may promote such post-targeting functions in the cell.

Molecular insights into mechanisms of intramembrane proteolysis through signal peptide peptidase (SPP)

2010 ◽  
Vol 427 (3) ◽  
pp. e1-e3 ◽  
Author(s):  
Bernd Schröder ◽  
Paul Saftig
Keyword(s):  
Membrane Protein ◽  
Signal Peptide ◽  
Cell Signalling ◽  
Dominant Negative ◽  
Signal Peptides ◽  
Intramembrane Proteolysis ◽  
Independent Manner ◽  
Interacting Protein ◽  
Signal Peptide Peptidase ◽  
Signalling Molecules

The processing of membrane-anchored signalling molecules and transcription factors by RIP (regulated intramembrane proteolysis) is a major signalling paradigm in eukaryotic cells. Intramembrane cleaving proteases liberate fragments from membrane-bound precursor proteins which typically fulfil functions such as cell signalling and regulation, immunosurveillance and intercellular communication. Furthermore, they are thought to be involved in the development and propagation of several diseases, such as Alzheimer's disease and hepatitis C virus infection. In this issue of the Biochemical Journal, Schrul and colleagues investigate the interaction of the endoplasmic reticulum-resident intramembrane cleaving SPP (signal peptide peptidase) with different type II oriented transmembrane proteins. A combination of co-immunoprecipitation experiments using wild-type and a dominant-negative SPP with electrophoretic protein separations under native conditions revealed selectivity of the interaction. Depending on the interacting protein, SPP formed complexes of different sizes. SPP could build tight interactions not only with signal peptides, but also with pre- and mis-folded proteins. Whereas signal peptides are direct substrates for SPP proteolysis, the study suggests that SPP may be involved in the controlled sequestration of possibly toxic membrane protein species in a proteolysis-independent manner. These large oligomeric membrane protein aggregates may then be degraded by the proteasome or autophagy.

Multislice calculations for quasi-periodic and non-periodic objects

1990 ◽  
Vol 48 (4) ◽  
pp. 138-139
Author(s):  
R. Herrera ◽  
A. Gómez
Keyword(s):  
Electron Diffraction ◽  
Computer Simulations ◽  
Periodic Table ◽  
Amorphous Materials ◽  
Space Group ◽  
Essential Step ◽  
Shape Effects ◽  
Atomic Scattering ◽  
Diffraction Patterns ◽  
Periodic Continuation

Computer simulations of electron diffraction patterns and images are an essential step in the process of structure and/or defect elucidation. So far most programs are designed to deal specifically with crystals, requiring frequently the space group as imput parameter. In such programs the deviations from perfect periodicity are dealt with by means of “periodic continuation”.However, for many applications involving amorphous materials, quasiperiodic materials or simply crystals with defects (including finite shape effects) it is convenient to have an algorithm capable of handling non-periodicity. Our program “HeGo” is an implementation of the well known multislice equations in which no periodicity assumption is made whatsoever. The salient features of our implementation are: 1) We made Gaussian fits to the atomic scattering factors for electrons covering the whole periodic table and the ranges [0-2]Å−1 and [2-6]Å−1.

APROXIMACIÓN A UNA CONCEPCIÓN TEÓRICO-METODOLÓGICA DE LOS PROCESOS DE PROFESIONALIZACIÓN PEDAGÓGICA EN LA EDUCACIÓN SUPERIOR.

2013 ◽  
Vol 1 (3) ◽  
Author(s):  
Olga Gloria Barbón Pérez ◽  
Julia Añorga Morales
Keyword(s):  
Higher Education ◽  
Key Words ◽  
Educación Superior ◽  
Comprehensive Understanding ◽  
Educacion Superior ◽  
Essential Step ◽  
Palabras Clave ◽  
Theoretical Conception ◽  
Design And Practice ◽  
Conscious Activity

El esclarecimiento de algunas de las concepciones que constituyen la base de los procesos de profesionalización pedagógica es un paso esencial para el éxito de los mismos. El presente artículo tiene como propósito aunar reflexiones que posibiliten un acercamiento hacia una concepción teórico-metodológica de los procesos de profesionalización pedagógica en la Educación Superior.El diseño y la puesta en práctica de los procesos de profesionalización pedagógica en la Educación Superior no pueden ser improvisados. Exigen, como actividad consciente, la consideración de determinados presupuestos teóricos y metodológicos que lo sustenten, y de su consideración como proceso pedagógico especial. Palabras clave: concepción teórica, concepción metodológica, profesionalización pedagógica.   ABSTRACT   Gaining on clarity concerning some of the conceptions that lie under the pedagogical professionalization processes is an essential step towards their own success. The article focuses on gathering insights that help get a more comprehensive understanding of a theoretic-methodological conception of the pedagogical professionalization processes in higher education. Both design and practice of these processes can not be improvised. They demand, as any other conscious activity, to take into account theoretical and methodological grounds and their consideration as a especial pedagogical process.   Key words: theoretical conception, methodological grounds, pedagogical professionalization.   Clarifying some of the concepts that form the basis of the processes of pedagogical professionalization is an essential step for their success.  This paper aims to join some reflections that enable the approaching to a theoretical-methodological conception of the processes of pedagogical professionalization in Higher Education.  Designing and implementing the processes of pedagogical professionalization cannot be improvised.  They demand, as a conscious activity, the consideration of certain supporting assumptions in theory and method, and their consideration as a special pedagogical process.   Keywords: theoretical conception, methodological conception, pedagogical professionalization. Recibido: Julio 2013 Aprobado: Agosto 2013

Gestagens in assisted reproductive technology programs

GYNECOLOGY ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 76-79
Author(s):  
Anastasia G Syrkasheva ◽  
Yana A Petrosyan ◽  
Natalia V Dolgushina
Keyword(s):  
Assisted Reproductive Technology ◽  
Luteal Phase ◽  
Ovarian Hyperstimulation Syndrome ◽  
Infertility Treatment ◽  
Reproductive Technology ◽  
Art Programs ◽  
Drug Effectiveness ◽  
Essential Step ◽  
Endogenous Steroid ◽  
Endogenous Steroid Hormones

Background. Luteal phase (LP) drug support is an important step in assisted reproductive technology (ART) programs efficacy. Aim. To present up-to-date data on an efficacy of LP hormonal support during ART cycles as well as to conduct a comparative analysis of various gestagen drug effectiveness. Materials and methods. To write this review domestic and foreign publications were searched in Russian and international search systems (PubMed, eLibrary, etc.) for the last 8 years. The review includs articles from peer-reviewed literature. Results. LP drug support becomes an essential step in infertility treatment in various ART programs. Although human chorionic gonadotropin drug injections in the posttransfer period leads to an activation of endogenous steroid hormones synthesis, exogenous hormones use is currently preferred because of not having a risk of ovarian hyperstimulation syndrome. Conclusions. The variety of progesterone drugs is accompanied by a lack of algorithms for their use in various clinical situations. Further studies are required to evaluate progesterone drugs efficacy for various subgroups of patients.

Precision Xe Plasma FIB Delayering for Physical Failure Analysis of Sub-20 nm Microprocessor Devices

2017 ◽  
Author(s):  
D. Zudhistira ◽  
V. Viswanathan ◽  
V. Narang ◽  
J.M. Chin ◽  
S. Sharang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Dielectric Films ◽  
Planar Surface ◽  
Chemical Methods ◽  
Root Cause ◽  
Essential Step ◽  
Dielectric Layers ◽  
Wet Chemical ◽  
20 Nm ◽  
Low K

Abstract Deprocessing is an essential step in the physical failure analysis of ICs. Typically, this is accomplished by techniques such as wet chemical methods, RIE, and mechanical manual polishing. Manual polishing suffers from highly non-uniform delayering particularly for sub 20nm technologies due to aggressive back-end-of-line scaling and porous ultra low-k dielectric films. Recently gas assisted Xe plasma FIB has demonstrated uniform delayering of the metal and dielectric layers, achieving a planar surface of heterogeneous materials. In this paper, the successful application of this technique to delayer sub-20 nm microprocessor chips with real defects to root cause the failure is presented.

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