Lipid transfer proteins do their thing anchored at membrane contact sites… but what is their thing?

Membrane contact sites are structures where two organelles come close together to regulate flow of material and information between them. One type of inter-organelle communication is lipid exchange, which must occur for membrane maintenance and in response to environmental and cellular stimuli. Soluble lipid transfer proteins have been extensively studied, but additional families of transfer proteins have been identified that are anchored into membranes by transmembrane helices so that they cannot diffuse through the cytosol to deliver lipids. If such proteins target membrane contact sites they may be major players in lipid metabolism. The eukaryotic family of so-called Lipid transfer proteins Anchored at Membrane contact sites (LAMs) all contain both a sterol-specific lipid transfer domain in the StARkin superfamily (related to StART/Bet_v1), and one or more transmembrane helices anchoring them in the endoplasmic reticulum (ER), making them interesting subjects for study in relation to sterol metabolism. They target a variety of membrane contact sites, including newly described contacts between organelles that were already known to make contact by other means. Lam1-4p target punctate ER-plasma membrane contacts. Lam5p and Lam6p target multiple contacts including a new category: vacuolar non-NVJ cytoplasmic ER (VancE) contacts. These developments confirm previous observations on tubular lipid-binding proteins (TULIPs) that established the importance of membrane anchored proteins for lipid traffic. However, the question remaining to be solved is the most difficult of all: are LAMs transporters, or alternately are they regulators that affect traffic more indirectly

Tubular lipid binding proteins (TULIPs) growing everywhere

Tubular lipid binding proteins (TULIPs) have become a focus of interest in the cell biology of lipid signalling, lipid traffic and membrane contact sites. Each tubular domain has an internal pocket with a hydrophobic lining that can bind a hydrophobic molecule such as a lipid. This allows TULIP proteins to carry lipids through the aqueous phase. TULIP domains were first found in a large family of extracellular proteins related to the bacterial permeability-inducing protein (BPI) and cholesterol ester transfer protein (CETP). Since then, the same fold and lipid transfer capacity have been found in SMP domains (so-called for their occurrence in synaptotagmin, mitochondrial and lipid binding proteins), which localise to intracellular membrane contact sites. Here the methods for identifying known TULIPs are described, and used to find previously unreported TULIPs, one in the silk polymer and another in prokaryotes illustrated by the E. coli protein YceB. The bacterial TULIP alters views on the likely evolution of the domain, suggesting its presence in the last universal common ancestor. The major function of TULIPs is to handle lipids, but we still do not know how they work in detail, or how many more remain to be discovered. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann

Combined first-principles calculation and neural-network correction approach for heat of formation

A promising new approach to improve the results of first-principles quantum mechanical calculations and to calibrate their uncertainties is presented. The approach is highly efficient compared to much more sophisticated first-principles methods of similar accuracy, and more importantly, is expected to be applied to much larger systems.published_or_final_versio

Using data envelopment analysis for supplier evaluation with environmental considerations

With the proliferation of outsourcing in global market place, supplier selection has become a key strategic consideration in forming a competitive supply chain. Supplier selection has been recognized as a multi-criteria decision making problem in which suppliers are evaluated according to multiple criteria such as price, quality, delivery and service simultaneously. Facing with excessive pressures from government and customers, increasing number of companies are beginning to consider environmental issues in the procurement and supplier selection process to practice the sustainable development. It is therefore necessary to measure a supplier’s environmental performance. This paper aims to find out what kind of environmental criteria can be applied to assess suppliers overall performances. The multicriteria decision making approach data envelopment analysis (DEA) is applied to help companies to evaluate suppliers’ various environmental performance and other capabilities simultaneously. © 2013 IEEE.published_or_final_versio

CSR and environmental criteria in supplier selection

Session - Green Manufacturing Technology: paper no. M3C1The APIEMS 2012 Conference proceedings' website is located at http://apiems.net/conf2012/The supplier selection issue in today’s world does not simply depend on price anymore. Other non-price criteria such as quality, delivery and overall capability are gradually gaining equal importance. Because of the globalization of trade, the world is becoming an increasingly open and global marketplace where the intense competition is urging companies to reduce the cost and development time of a new product. Companies are forced to take every possible factor into consideration when making the strategic decision to minimize costs and product development time. That means besides taking price into consideration, companies now also has to assess the overall capability of the suppliers, such as production capability, technological capability, company reputation and other factors that are hard to be quantified, in order to make the most informed decision to strive for a balance between lowering profits and rising costs. Different companies have their own ways in carrying out the supplier selection process that aligns with their corporate strategy. This paper is interested in what criteria are used in supplier evaluation and the ranking of the criteria importance. In particular, the focus is the incorporation of corporate social responsibility (CSR) and environmental responsibility (ER) requirements into supplier selection. With the increasing awareness of CSR and ER, large international corporations have been paying more attention in selecting suppliers that are capable of adhering to the practice of sustainability. Hence, this paper aims to find out what criteria or performance indicators are adopted by companies to assess their suppliers, and how much importance CSR and ER contributes to the final decision of the selected supplier. A multi-agent system is implemented with a multi criteria decision making model to incorporate the criteria identified for evaluating supplier performance and selecting the most suitable supplier.published_or_final_versio

Advances on the Transfer of Lipids by Lipid Transfer Proteins

Transfer of lipid across the cytoplasm is an essential process for intracellular lipid traffic. Lipid transfer proteins (LTPs) are defined by highly controlled in vitro experiments. The functional relevance of these is supported by evidence for the same reactions inside cells. Major advances in the LTP field have come from structural bioinformatics identifying new LTPs, and from the development of countercurrent models for LTPs. However, the ultimate aim is to unite in vitro and in vivo data, and this is where much progress remains to be made. Even where in vitro and in vivo experiments align, rates of transfer tend not to match. Here we set out some of the advances that might test how LTPs work

Response Capabilities to Natural Disasters: Case Studies of Thailand Flooding

This paper explores and identifies the natural disaster response capabilities, and uncovers the underlying processes and mechanisms of which businesses respond to natural disasters. Evidence from two comparative extreme cases of factories dealing with the Thailand 2011 flood were examined, which resulted in a process framework that exhibits enabler response capabilities, organization response capabilities and underpinning response capabilities required to achieve a successful response. It highlights that the successful factory had better flexibility, speed and continuous updating enabler response capabilities as well as activated, adaptable and the ability to extend higher amounts of underpinning response capabilities

The product of C9orf72, a gene strongly implicated in neurodegeneration, is structurally related to DENN Rab-GEFs

Fronto-temporal dementia (FTD) and amyotrophic lateral sclerosis (ALS, also called motor neuron disease, MND) are severe neurodegenerative diseases that show considerable overlap at the clinical and cellular level. The most common single mutation in families with FTD or ALS has recently been mapped to a non-coding repeat expansion in the uncharacterized gene C9ORF72. Although a plausible mechanism for disease is that aberrant C9ORF72 mRNA poisons splicing, it is important to determine the cellular function of C9ORF72, about which nothing is known