Understanding the yeast host cell response to recombinant membrane protein production

Membrane proteins are drug targets for a wide range of diseases. Having access to appropriate samples for further research underpins the pharmaceutical industry's strategy for developing new drugs. This is typically achieved by synthesizing a protein of interest in host cells that can be cultured on a large scale, allowing the isolation of the pure protein in quantities much higher than those found in the protein's native source. Yeast is a popular host as it is a eukaryote with similar synthetic machinery to that of the native human source cells of many proteins of interest, while also being quick, easy and cheap to grow and process. Even in these cells, the production of human membrane proteins can be plagued by low functional yields; we wish to understand why. We have identified molecular mechanisms and culture parameters underpinning high yields and have consolidated our findings to engineer improved yeast host strains. By relieving the bottlenecks to recombinant membrane protein production in yeast, we aim to contribute to the drug discovery pipeline, while providing insight into translational processes.

Editorial

The year so far has been a slow start for many businesses, but at least we have not seen the collapse of as many businesses that we were seeing around two years ago. We are, however, still well and truly in the midst of a global recession. Interest rates are still at an all time low, UK house prices seem to be showing little signs of increase (except in London where everyone still seems to want to live!) and for the ardent shopper there are bargains to be had everywhere. It seems strange that prices on the high street do not seem to have increased in over ten years. Mobile phones, DVD players even furniture seems to be cheaper than they used to be. Whist much of this is down to cheaper manufacturing and the rest could probably be explained by competition within the market place. Does this mean that quality suffered too? Now that we live in a world when if a television is not working it is thrown away and replaced. There was a time when you would take it to some odd looking man that your father would know who could fix it for you. (I remember our local television fix-it man, with his thick rimmed bifocal spectacles and a poor comb-over; he had cardboard boxes full of resistors and electrical wires on the floor of his front room that smelt of soldering irons!) Is this consumerism at an extreme or has this move to disposability made us a better society? Before you think these are just ramblings there is a point to this. According to latest global figures of contact lens sales the vast majority of contact lenses fitted around the world are daily, fortnightly or monthly disposable hydrogel lenses. Certainly in the UK over 90% of lenses are disposable (with daily disposables being the most popular, having a market share of over 50%). This begs the question – is this a good thing? Maybe more importantly, do our patients benefit? I think it is worth reminding ourselves why we went down the disposability route with contact lenses in the first place, and unlike electrical goods it was not just so we did not have to take them for repair! There are the obvious advantages of overcoming problems of breakage and tearing of lenses and the lens deterioration with age. The lenses are less likely to be contaminated and the disinfection is either easier or not required at all (in the case of daily disposable lenses). Probably the landmark paper in the field was the work more commonly known as the ‘Gothenburg Study’. The paper, entitled ‘Strategies for minimizing the Ocular Effects of Extended Contact Lens Wear’ published in the American Journal of Optometry in 1987 (volume 64, pages 781-789) by Holden, B.A., Swarbrick, H.A., Sweeney, D.F., Ho, A., Efron, N., Vannas, A., Nilsson, K.T. They suggested that contact lens induced ocular effects were minimised by: •More frequently removed contact lenses •More regularly replaced contact lenses •A lens that was more mobile on the eye (to allow better removal of debris) •Better flow of oxygen through the lens All of these issues seem to be solved with disposability, except the oxygen issue which has been solved with the advent of silicone hydrogel materials. Newer issues have arisen and most can be solved in practice by the eye care practitioner. The emphasis now seems to be on making lenses more comfortable. The problems of contact lens related dry eyes symptoms seem to be ever present and maybe this would explain why in the UK we have a pretty constant contact lens wearing population of just over three million but every year we have over a million dropouts! That means we must be attracting a million new wearers every year (well done to the marketing departments!) but we are also losing a million wearers every year. We certainly are not losing them all to the refractive surgery clinics. We know that almost anyone can now wear a contact lens and we know that some lenses will solve problems of sharper vision, some will aid comfort, and some will be useful for patients with dry eyes. So if we still have so many dropouts then we must be doing something wrong! I think the take home message has to be ‘must try harder’! I must end with an apology for two errors in my editorial of issue 1 earlier this year. Firstly there was a typo in the first sentence; I meant to state that it was 40 years not 30 years since the first commercial soft lens was available in the UK. The second error was one that I was unaware of until colleagues Geoff Wilson (Birmingham, UK) and Tim Bowden (London, UK) wrote to me to explain that soft lenses were actually available in the UK before 1971 (please see their ‘Letters to the Editor’ in this issue). I am grateful to both of them for correcting the mistake.

Why is Werner Sombart not part of the core of classical sociologists? From fame to (near) oblivion:From Fame to (Near) Oblivion

The life and work of Werner Sombart poses an intellectual puzzle in the genealogy of modern social theorists. During his lifetime, Sombart was probably the most influential and prominent social scientist in Germany as well as in many other countries. Today he is among the least known social scientists. Why did he lose his status as one of the most brilliant and influential scholars and intellectuals of the 20th century? Why is his work almost forgotten today? While Weber's thesis about the influence of Protestantism on the development of capitalism is widely known, even beyond sociological circles, few sociologists today know that Sombart had an alternative explanation. An obvious explanation for Sombart's fall from grace is his embrace of Nazism. As Heidegger provides a counter-example, Sombart's fate requires a more complex explanation. In addition, we explore the different reception of his work in economic and sociological circles as compared to cultural theory and history. © 2001, SAGE Publications. All rights reserved.

The effect of ageing on macrophage Toll-like receptor-mediated responses in the fight against pathogens

The cellular changes during ageing are incompletely understood yet immune system dysfunction is implicated in the age-related decline in health. The acquired immune system shows a functional decline in ability to respond to new pathogens whereas serum levels of cytokines are elevated with age. Despite these age-associated increases in circulating cytokines, the function of aged macrophages is decreased. Pathogen-associated molecular pattern receptors such as Toll-like receptors (TLRs) are vital in the response of macrophages to pathological stimuli. Here we review the evidence for defective TLR signalling in normal ageing. Gene transcription, protein expression and cell surface expression of members of the TLR family of receptors and co-effector molecules do not show a consistent age-dependent change across model systems. However, there is evidence for impaired downstream signalling events, including inhibition of positive and activation of negative modulators of TLR induced signalling events. In this paper we hypothesize that despite a poor inflammatory response via TLR activation, the ineffective clearance of pathogens by macrophages increases the duration of their activation and contributes to perpetuation of inflammatory responses and ageing.

Why are health care interventions delivered over the internet? A systematic review of the published literature

Background: As Internet use grows, health interventions are increasingly being delivered online. Pioneering researchers are using the networking potential of the Internet, and several of them have evaluated these interventions. Objective: The objective was to review the reasons why health interventions have been delivered on the Internet and to reflect on the work of the pioneers in this field in order to inform future research. Methods: We conducted a qualitative systematic review of peer-reviewed evaluations of health interventions delivered to a known client/patient group using networked features of the Internet. Papers were reviewed for the reasons given for using the Internet, and these reasons were categorized. Results: We included studies evaluating 28 interventions plus 9 interventions that were evaluated in pilot studies. The interventions were aimed at a range of health conditions. Reasons for Internet delivery included low cost and resource implications due to the nature of the technology; reducing cost and increasing convenience for users; reduction of health service costs; overcoming isolation of users; the need for timely information; stigma reduction; and increased user and supplier control of the intervention. A small number of studies gave the existence of Internet interventions as the only reason for undertaking an evaluation of this mode of delivery. Conclusions: One must remain alert for the unintended effects of Internet delivery of health interventions due to the potential for reinforcing the problems that the intervention was designed to help. Internet delivery overcomes isolation of time, mobility, and geography, but it may not be a substitute for face-to-face contact. Future evaluations need to incorporate the evaluation of cost, not only to the health service but also to users and their social networks. When researchers report the outcomes of Internet-delivered health care interventions, it is important that they clearly state why they chose to use the Internet, preferably backing up their decision with theoretical models and exploratory work. Evaluation of the effectiveness of a health care intervention delivered by the Internet needs to include comparison with more traditional modes of delivery to answer the following question: What are the added benefits or disadvantages of Internet use that are particular to this mode of delivery? © Griffiths, Frances, Lindenmeyer, Antje, Powell, John, Thorogood, Margaret.

Why critical pedagogy and popular education matter today

Few today doubt that English Higher Education (HE), like the wider world in which it is located, is in crisis. This is, in part, an economic crisis, as the government response to the current recession seems to be that of introducing the kind of neoliberal ‘shock doctrine’ (Klein 2007) or ‘shock therapy’ (Harvey 2005) that previously resulted in swingeing cuts in public services in Southern nations. Our aim in producing this volume is that these contributions help develop a collective response to the seeming limits of these conditions. We view the strength of these contributions in part as providing palpable evidence of how we and our colleagues are acting with critical hope under current conditions so that we might encourage others to work with us to build, together, more progressive formal and informal education systems that address and seek to redress multiple injustices of the world today.

Why are MD simulated protein folding times wrong?

The question of significant deviations of protein folding times simulated using molecular dynamics from experimental values is investigated. It is shown that in the framework of Markov State Model (MSM) describing the conformational dynamics of peptides and proteins, the folding time is very sensitive to the simulation model parameters, such as forcefield and temperature. Using two peptides as examples, we show that the deviations in the folding times can reach an order of magnitude for modest variations of the molecular model. We, therefore, conclude that the folding rate values obtained in molecular dynamics simulations have to be treated with care.

Why are optimistic entrepreneurs successful? An application of the regulatory focus theory

Does entrepreneurial optimism affect business performance? Using a unique data set based on repeated survey design, we investigate this relationship empirically. Our measures of ëoptimismí and ërealismí are derived from comparing the turnover growth expectations of ...133 owners-managers with the actual outcomes one year later. Our results indicate that entrepreneurial optimists perform significantly better in terms of profits than pessimists. Moreover, it is the optimist-realist combination that performs best. We interpret our results using regulatory focus theory.

Why are optimistic entrepreneurs successful? An application of the regulatory focus theory

Does entrepreneurial optimism affect business performance? Using a unique data set based on repeated survey design, we investigate this relationship empirically. Our measures of ‘optimism’ and ‘realism’ are derived from comparing the turnover growth expectations of 133 owners-managers with the actual outcomes one year later. Our results indicate that entrepreneurial optimists perform significantly better in terms of profits than pessimists. Moreover, it is the optimist-realist combination that performs best. We interpret our results using regulatory focus theory.

Why is it possible to detect doped regions of semiconductors in low voltage SEM:a review and update

There is an urgent need for fast, non-destructive and quantitative two-dimensional dopant profiling of modern and future ultra large-scale semiconductor devices. The low voltage scanning electron microscope (LVSEM) has emerged to satisfy this need, in part, whereby it is possible to detect different secondary electron yield values (brightness in the SEM signal) from the p-type to the n-type doped regions as well as different brightness levels from the same dopant type. The mechanism that gives rise to such a secondary electron (SE) contrast effect is not fully understood, however. A review of the different models that have been proposed to explain this SE contrast is given. We report on new experiments that support the proposal that this contrast is due to the establishment of metal-to-semiconductor surface contacts. Further experiments showing the effect of instrument parameters including the electron dose, the scan speeds and the electron beam energy on the SE contrast are also reported. Preliminary results on the dependence of the SE contrast on the existence of a surface structure featuring metal-oxide semiconductor (MOS) are also reported. Copyright © 2005 John Wiley & Sons, Ltd.

Why are aggregate equity payouts pro-cyclical?

We use two general equilibrium models to explain why changes in the external economic environment result in pro-cyclical aggregate dividend payout behavior. Both models that we consider endogenize low elasticity of investment. The first model incorporates capital adjustment costs, while the second one assumes that risk-averse managers maximize their own objective function rather than shareholder wealth. We show that, while both models generate pro-cyclical aggregate dividends, a feature consistent with the observed business-cycle pattern of payouts from well-diversified portfolios, the second model provides a more likely explanation for this effect. Our findings emphasize the importance of incorporating agency conflicts when considering the relationship between the external economic environment and the financial behavior of businesses.

Why do doctored images distort memory?

Doctored images can cause people to believe in and remember experiences that never occurred, yet the underlying mechanism(s) responsible are not well understood. How does compelling false evidence distort autobiographical memory? Subjects were filmed observing and copying a Research Assistant performing simple actions, then they returned 2 days later for a memory test. Before taking the test, subjects viewed video-clips of simple actions, including actions that they neither observed nor performed earlier. We varied the format of the video-clips between-subjects to tap into the source-monitoring mechanisms responsible for the 'doctored-evidence effect.' The distribution of belief and memory distortions across conditions suggests that at least two mechanisms are involved: doctored images create an illusion of familiarity, and also enhance the perceived credibility of false suggestions. These findings offer insight into how external evidence influences source-monitoring. © 2009 Elsevier Inc. All rights reserved.

Corporate coalitions and policy making in the European Union:how and why British American tobacco promoted "better regulation"

Over the past fifteen years, an interconnected set of regulatory reforms, knownas Better Regulation, has been adopted across Europe, marking a significant shift in theway that European Union policies are developed. There has been little exploration of the origins of these reforms, which include mandatory ex ante impact assessment. Drawing on documentary and interview data, this article discusses how and why large corporations, notably British American Tobacco (BAT), worked to influence and promote these reforms. Our analysis highlights (1) howpolicy entrepreneurs with sufficient resources (such as large corporations) can shape the membership and direction of advocacy coalitions; (2) the extent to which "think tanks" may be prepared to lobby on behalf of commercial clients; and (3) why regulated industries (including tobacco) may favor the use of "evidence tools," such as impact assessments, in policy making. We argue that a key aspect of BAT's ability to shape regulatory reform involved the deliberate construction of a vaguely defined idea that could be strategically adapted to appeal to diverse constituencies.We discuss the theoretical implications of this finding for the Advocacy Coalition Framework, as well as the practical implications of the findings for efforts to promote transparency and public health in the European Union.

Formative variables and unreal variables:why the formative MIMIC model is invalid

In this rejoinder, we provide a response to the three commentaries written by Diamantopoulos, Howell, and Rigdon (all this issue) on our paper The MIMIC Model and Formative Variables: Problems and Solutions (also this issue). We contrast the approach taken in the latter paper (where we focus on clarifying the assumptions required to reject the formative MIMIC model) by spending time discussing what assumptions would be necessary to accept the use of the formative MIMIC model as a viable approach. Importantly, we clarify the implications of entity realism and show how it is entirely logical that some theoretical constructs can be considered to have real existence independent of their indicators, and some cannot. We show how the formative model only logically holds when considering these ‘unreal’ entities. In doing so, we provide important counter-arguments for much of the criticisms made in Diamantopoulos’ commentary, and the distinction also helps clarify a number of issues in the commentaries of Howell and Rigdon (both of which in general agree with our original paper). We draw together these various threads to provide a set of conceptual tools researchers can use when thinking about the entities in their theoretical models.

Why resilience managers aren’t resilient, and what human resource management can do about it

Prior resilience research typically focuses on either the individual or the organisational level of analysis, emphasises resilience in relation to day-to-day stressors rather than extreme events and is empirically under-developed. In response, our study inductively theorises about the relationships between individual and organisational resilience, drawing upon a large-scale study of resilience work in UK and French organisations. Our first-hand accounts of resilience work reveal the micro-processes involved in producing resilient organisations, and highlight the challenges experienced in doing resilience work in large organisations. We show that these micro-processes have significant implications for resilience at both individual and organisational levels, and draw implications for how HRM interventions can help to promote individual, and thus organisational, resilience.