Association of ezrin with intercellular adhesion molecule-1 and -2 (ICAM-1 and ICAM-2). Regulation by phosphatidylinositol 4, 5-bisphosphate

Ezrin is a cytoplasmic linker molecule between plasma membrane components and the actin-containing cytoskeleton. We studied whether ezrin is associated with intercellular adhesion molecule (ICAM)-1, -2, and -3. In transfected cells, ICAM-1 and ICAM-2 colocalized with ezrin in microvillar projections, whereas an ICAM-1 construct attached to cell membrane via a glycophosphatidylinositol anchor was uniformly distributed on the cell surface. An interaction of ICAM-2 and ezrin was seen by affinity precipitation, microtiter binding assay, coimmunoprecipitation, and surface plasmon resonance methods. The calculated KD value was 3.3 x 10(-7) M. Phosphatidylinositol 4, 5-bisphosphate (PtdIns(4,5)P2) induced an interaction of ezrin and ICAM-1 and enhanced the interaction of ezrin and ICAM-2, but ICAM-3 did not bind ezrin even in the presence of PtdIns(4,5)P2. PtdIns(4, 5)P2 was shown to bind to cytoplasmic tails of ICAM-1 and ICAM-2, which are the first adhesion proteins demonstrated to interact with PtdIns(4,5)P2. The results indicate an interaction of ezrin with ICAM-1 and ICAM-2 and suggest a regulatory role of phosphoinositide signaling pathways in regulation of ICAM-ezrin interaction.     

Identification of late-stage glycosylation steps in the biosynthetic pathway of the anthracycline nogalamycin

Nogalamycin is an anthracycline antibiotic that has been shown to exhibit significant cytotoxicity. Its biological activity requires two deoxysugar moieties: nogalose and nogalamine, which are attached at C7 and C1, respectively, of the aromatic polyketide aglycone. Curiously, the aminosugar nogalamine is also connected through a C-C bond between C2 and C5'. Despite extensive molecular genetic characterization of early biosynthetic steps, nogalamycin glycosylation has not been investigated in detail. Here we show that expression of the majority of the gene cluster in Streptomyces albus led to accumulation of three new anthracyclines, which unexpectedly included nogalamycin derivatives in which nogalamine was replaced either by rhodosamine with the C-C bond intact (nogalamycin R) or by 2-deoxyfucose without the C-C bond (nogalamycin F). In addition, a monoglycosylated intermediate-3',4'-demethoxynogalose-1-hydroxynogalamycinone-was isolated. Importantly, when the remaining biosynthetic genes were introduced into the heterologous host by using a two-plasmid system, nogalamycin could be isolated from the cultures, thus indicating that the whole gene cluster had been identified. We further show that one of the three glycosyltransferases (GTs) residing in the cluster-snogZ-appears to be redundant, whereas gene inactivation experiments revealed that snogE and snogD act as nogalose and nogalamine transferases, respectively. The substrate specificity of the nogalamine transferase SnogD was demonstrated in vitro: the enzyme was able to remove 2deoxyfucose from nogalamycin F. All of the new compounds were found to inhibit human topoisomerase I in activity measurements, whereas only nogalamycin R showed minor activity against topoisomerase II.     

European Consumers' Perceptions of Time–Temperature Indicators in Food Packaging

Food quality is an essential aspect of the food industry. Time–temperature indicator (TTI) technology has the capability to provide information on temperature fluctuations that temperature‐sensitive food products have undergone. However, the adoption of the TTI technology in the consumer market has yet to materialize despite the many benefits that TTIs bring to food manufacturers, retailers and consumers. One of the reasons for this could be the general lack of knowledge regarding consumers' perceptions of TTIs. The aim of this study is to understand the consumers' knowledge, interest and perceptions of TTIs. To reach this aim, 16 focus group discussions and a quantitative survey were conducted in four European countries (Finland, Greece, France and Germany) during May–October 2012. Consumers' views on both the TTI technology concept and two commercially available TTI applications were studied. The results of the study show that consumers in all countries appreciate and understand TTI technology and associate differing benefits with it, especially so in warmer countries. On the other hand, the studied applications did not meet all consumers' expectations implying the need for further work to enable TTIs to gain a wider acceptance. Copyright © 2014 John Wiley & Sons, Ltd.     

The Rieske Oxygenase SnoT Catalyzes 2′′-Hydroxylation of l-Rhodosamine in Nogalamycin Biosynthesis

Nogalamycin is an anthracycline anti-cancer agent that intercalates into the DNA double helix. The binding is facilitated by two carbohydrate units, l -nogalose and l -nogalamine, that interact with the minor and major grooves of DNA, respectively. However, recent investigations have shown that nogalamycin biosynthesis proceeds through the attachment of l -rhodosamine (2′′-deoxy-4′′-epi-l -nogalamine) to the aglycone. Herein, we demonstrate that the Rieske enzyme SnoT catalyzes 2′′-hydroxylation of l -rhodosamine as an initial post-glycosylation step. Furthermore, we establish that the reaction order continues with 2–5′′ carbocyclization and 4′′ epimerization by the non-heme iron and 2-oxoglutarate-dependent enzymes SnoK and SnoN, respectively. These late-stage tailoring steps are important for the bioactivity of nogalamycin due to involvement of the 2′′- and 4′′-hydroxy groups of l -nogalamine in hydrogen bonding interactions with DNA.     

Consumers in the green electricity market in Finland

“Green” electricity, i.e. electricity produced from environmentally less harmful sources and marketed as such, has been available to Finnish households since 1998, but the demand for it has remained low. In this paper we discuss the barriers identified by consumers to purchasing green electricity and contrast these with the interpretation energy sector actors give to consumer passivity. The empirical material consists of thematic interviews. Energy policy actors often assume that consumers’ passivity signifies their lack of interest or low environmental consciousness. This results partly from the failure to differentiate between the roles of consumer and citizen. The interpretation the energy sector actors give to consumer passivity and the role they assign to consumers affect the direction of green electricity policy. We argue that consumers need more information on both the environmental impact of different electricity products and in particular about the electricity supply and electricity contracts in a liberalised electricity market if they are to become active in the market.