Framing Excellence in teaching: Is it the right thing?

When the ‘Teaching Excellence Framework’ (TEF) was announced earlier this year, I was wondering what it actually meant - and I still have lots of questions about this Government initiative. First of all, I wonder why we want to measure excellence in teaching? I agree that with the increase of fees to £9k and possibly even higher, there is pressure on HEIs to be accountable for the service they deliver. While a university’s contribution to research has been measured over the years through the various ‘Research Assessment Exercises’, followed by the latest ‘Research Excellence Framework’, the assessment of efficient education has been neglected. It is therefore only fitting that we also begin to hold universities accountable for the provision of excellence in education

Ribonucleoparticle-independent transport of proteins into mammalian microsomes

There are at least two different mechanisms for the transport of secretory proteins into the mammalian endoplasmic reticulum. Both mechanisms depend on the presence of a signal peptide on the respective precursor protein and involve a signal peptide receptor on the cis-side and signal peptidase on the trans-side of the membrane. Furthermore, both mechanisms involve a membrane component with a cytoplasmically exposed sulfhydryl. The decisive feature of the precursor protein with respect to which of the two mechanisms is used is the chain length of the polypeptide. The critical size seems to be around 70 amino acid residues (including the signal peptide). The one mechanism is used by precursor proteins larger than about 70 amino acid residues and involves two cytosolic ribonucleoparticles and their receptors on the microsomal surface. The other one is used by small precursor proteins and relies on the mature part within the precursor molecule and a cytosolic ATPase

Pancreas specific protein disulfide isomerase, PDIp, is in transient contact with secretory proteins during late stages of translocation

AbstractProtein disulfide isomerase (PDI) and an additional lumenal protein of dog pancreas microsomes were previously observed to be in transient contact with secretory proteins during late stages of their co- or posttranslational translocation into these mammalian microsomes. The second protein was characterized as a 57 kDa glycoprotein. Here we identified this glycoprotein as the canine equivalent of human PDIp, a protein which was recently described as a new protein disulfide isomerase which is highly expressed in human pancreas. Canine PDIp is also a very abundant protein, its concentration in pancreatic microsomes approaches the concentration of PDI and of the major microsomal molecular chaperones. Apparently, PDIp shares with PDI not just the enzymatic but also the polypeptide binding or chaperoning activity. Furthermore, we suggest that PDIp, too, can be involved in completion of cotranslational as well as posttranslational translocation of proteins into mammalian microsomes

Protein export in prokaryotes and eukaryotes Theme with variations

AbstractProtein export in prokaryotes as well as in eukaryotes can be defined as protein transport across the plasma membrane. In both types of organisms there are various apparently ATP-dependent transport mechanisms which can be distinguished from one another and which show similarities when the prokaryotic mechanism is compared with the respective eukaryotic mechanism. First, one can distinguish between transport mechanisms which involve so-called signal or leader peptides and those which do not. The latter mechanisms seem to employ ATP-dependent transport systems which belong to the family of oligopeptide permeases and multiple drug resistance proteins. Second, in signal or leader peptide-dependent transport one can distinguish between transport mechanisms which involve ribonucleoparticles and those which employ molecular chaperones. Both mechanisms appear to converge at the level of ATP-dependent translocases

CMD: A Database to Store the Bonding States of Cysteine Motifs with Secondary Structures

Computational approaches to the disulphide bonding state and its connectivity pattern prediction are based on various descriptors. One descriptor is the amino acid sequence motifs flanking the cysteine residue motifs. Despite the existence of disulphide bonding information in many databases and applications, there is no complete reference and motif query available at the moment. Cysteine motif database (CMD) is the first online resource that stores all cysteine residues, their flanking motifs with their secondary structure, and propensity values assignment derived from the laboratory data. We extracted more than 3 million cysteine motifs from PDB and UniProt data, annotated with secondary structure assignment, propensity value assignment, and frequency of occurrence and coefficiency of their bonding status. Removal of redundancies generated 15875 unique flanking motifs that are always bonded and 41577 unique patterns that are always nonbonded. Queries are based on the protein ID, FASTA sequence, sequence motif, and secondary structure individually or in batch format using the provided APIs that allow remote users to query our database via third party software and/or high throughput screening/querying. The CMD offers extensive information about the bonded, free cysteine residues, and their motifs that allows in-depth characterization of the sequence motif composition

Interaction of the periplasmic peptidylprolyl cis-trans isomerase SurA with model peptides: The N-terminal region of SurA is essential and sufficient for peptide binding

One of the rate-limiting steps in protein folding has been shown to be the cis-trans isomerization of proline residues, which is catalyzed by a range of peptidylprolyl cis-trans isomerases. To characterize the interaction between model peptides and the periplasmic peptidylprolyl cis-trans isomerase SurA from E. coli, we employed a chemical cross-linking strategy that has been used previously to elucidate the interaction of substrates with other folding catalysts. The interaction between purified SurA and model peptides was significant in that it showed saturation and was abolished by denaturation of SurA; however the interaction was independent of the presence of proline residues in the model peptides. From results obtained by limited proteolysis we conclude that an N-terminal fragment of SurA, comprising 150 amino acids that do not contain the active sites involved in the peptidylprolyl cis-trans isomerization, is essential for the binding of peptides by SurA. This was confirmed by probing the interaction of the model peptide with the recombinant N-terminal fragment, expressed in Escherichia coli. Hence we propose that, similar to protein disulfide isomerase and other folding catalysts, SurA exhibits a modular architecture composed of a substrate binding domain and distinct catalytically active domains

Innovative pedagogies series: Videos for learning and teaching

The expression ‘chalk and talk’ has been used synonymously for boring and old-fashioned teaching style, but this approach can have advantages over more ‘modern’ teaching styles, notably the use of slides and asynchronous online delivery of lectures (for review see Seth 2010). However, a major disadvantage of this teaching style is the transient nature of the notes scribbled on the board: once the notes and explanations have been wiped off, they are gone, persisting only in the more or less complete notes of the students. As a result students focus their attention predominantly on trying to keep up with copying the notes from the board while at the same time listening to the lecturer, which can easily lead to cognitive load (Mayer 2003). It is not a surprise that many students find it challenging to engage with the topic while anxiously trying to get a complete set of notes and at the same time listening to the lecturer. In my view, students should focus on the development of the topic rather than copying the board contents. It was important to me to improve the learning experience and to provide accessible, flexible and diverse learning opportunities that improve student engagement with their studies

Comparison of computational tools for protein-protein interaction (PPI) mapping and analysis

Several visualization tools for the mapping of protein-protein interactions have been developed in recent years. However, a systematic comparison of the virtues and limitations of different PPI visualization tools has not been carried out so far. In this study, we compare seven commonly used visualization tools, based on input and output file format, layout algorithm, database integration, Gene Ontology annotation and accessibility of each tool. The assessment was carried out based on brain disease datasets. Our suggested tools, NAViGaTOR, Cytoscape and Gephi perform competitively as PPI network visualization tools, can be a reference for future researches on PPI mapping and analysis