Crystal structure of the carbohydrate recognition domain of p58/ERGIC-53, a protein involved in glycoprotein export from the endoplasmic reticulum

p58/ERGIC-53 is an animal calcium-dependent lectin that cycles between the endoplasmic reticulum (ER) and the Golgi complex and appears to act as a cargo receptor for a subset of soluble glycoproteins exported from the ER. We have determined the crystal structure of the carbohydrate recognition domain (CRD) of p58, the rat homologue of human ERGIC-53, to 1.46 A resolution. The fold and ligand binding site are most similar to those of leguminous lectins. The structure also resembles that of the CRD of the ER folding chaperone calnexin and the neurexins, a family of non-lectin proteins expressed on neurons. The CRD comprises one concave and one convex beta-sheet packed into a beta-sandwich. The ligand binding site resides in a negatively charged cleft formed by conserved residues. A large surface patch of conserved residues with a putative role in protein-protein interactions and oligomerization lies on the opposite side of the ligand binding site. Together with previous functional data, the structure defines a new and expanding class of calcium-dependent animal lectins and provides a starting point for the understanding of glycoprotein sorting between the ER and the Golgi.     

Environmental fluctuations facilitate species co-existence and increase decomposition in communities of wood decay fungi

Correlations between mast fruiting of bilberry Vaccinium myrtillus and peak levels of Clethrionomys-voles have been reported from both Norway and Finland, but there has been a discussion whether this is a bottom-up or a top-down relationship. In a multiple regression model, 65% of the variation in a bilberry production index calculated from game reports from southern Norway 1932–1977 could be explained by the berry index of the two preceding years and climate factors acting during key stages of the flowering cycle. High vole populations in previous years did not contribute to explain the fluctuation in berry production. I used the selected model and climate data to predict bilberry production for the period 1978–2004. Predicted berry indices of the current and previous year explained 38% and the total amount of precipitation in May–June explained 16% of the variation in a log-transformed snap-trapping index of bank vole Clethrionomys glareolus 1980–2004. The vole index was not related to any of the climate variables used to predict berry production. This pattern supports the hypothesis that vole cycles are generated by changes in plant chemistry due to climate-synchronized mast fruiting.     

Global unbalance in seaweed production,research effort and biotechnology markets

Exploitation of the world's oceans is rapidly growing as evidenced by a booming patent market of marine products including seaweed, a resource that is easily accessible without sophisticated bioprospecting technology and that has a high level of domestication globally. The investment in research effort on seaweed aquaculture has recently been identified to be the main force for the development of a biotechnology market of seaweed-derived products and is a more important driver than the capacity of seaweed production. Here, we examined seaweed patent registrations between 1980 and 2009 to assess the growth rate of seaweed biotechnology, its geographic distribution and the types of applications patented. We compare this growth with scientific investment in seaweed aquaculture and with the market of seaweed production. We found that both the seaweed patenting market and the rate of scientific publications are rapidly growing (11% and 16.8% per year respectively) since 1990. The patent market is highly geographically skewed (95% of all registrations belonging to ten countries and the top two holding 65% of the total) compared to the distribution of scientific output among countries (60% of all scientific publications belonging to ten countries and the top two countries holding a 21%), but more homogeneously distributed than the production market (with a 99.8% belonging to the top ten countries, and a 71% to the top two). Food industry was the dominant application for both the patent registrations (37.7%) and the scientific publications (21%) followed in both cases by agriculture and aquaculture applications. This result is consistent with the seaweed taxa most represented. Kelp, which was the target taxa for 47% of the patent registrations, is a traditional ingredient in Asian food and Gracilaria and Ulva, which were the focus of 15% and 13% of the scientific publications respectively, that are also used in more sophisticated applications such as cosmetics, chemical industry or bioremediation. Our analyses indicate a recent interest of non-seaweed producing countries to play a part in the seaweed patenting market focusing on more sophisticated products, while developing countries still have a limited share in this booming market. We suggest that this trend could be reverted by promoting partnerships for R and D to connect on-going efforts in aquaculture production with the emerging opportunities for new biotech applications of seaweed products.     

Determination of site-specificity of S-glutathionylated cellular proteins

Redox modification by S-glutathionylation is an expanding field within cell signalling research. However, the methods available for analysis of S-glutathionylated proteins in complex mixtures are not sufficiently accurate to specifically and in a high-throughput manner on a structural level establish the effects of S-glutathionylation on the individual proteins. A method has been developed for rapid identification of the S-glutathionylation sites of proteins in diamide-treated ECV304 cells, through tagging of deglutathionylated proteins with a cysteine-reactive biotin-affinity tag, trypsinisation, avidin-affinity purification of tagged peptides, and subsequent analysis by liquid chromatography and quadrupole time-of-flight tandem mass spectrometry. The method has led to identification of the glutathionylation sites of gamma-actin (Cys(217)), heat shock protein 60 (Cys(447)), and elongation factor 1-alpha-1 (Cys(411)). Further developments of accuracy within the field of peptide-affinity capture and mass spectrometry are discussed.     

Embryonic expression of the common progeroid lamin A splice mutation arrests postnatal skin development

Hutchinson–Gilford progeria syndrome (HGPS) and restrictive dermopathy (RD) are two laminopathies caused by mutations leading to cellular accumulation of prelamin A or one of its truncated forms, progerin. One proposed mechanism for the more severe symptoms in patients with RD compared with HGPS is that higher levels of farnesylated lamin A are produced in RD. Here, we show evidence in support of that hypothesis. Overexpression of the most common progeroid lamin A mutation (LMNA c.1824C>T, p.G608G) during skin development results in a severe phenotype, characterized by dry scaly skin. At postnatal day 5 (PD5), progeroid animals showed a hyperplastic epidermis, disorganized sebaceous glands and an acute inflammatory dermal response, also involving the hypodermal fat layer. PD5 animals also showed an upregulation of multiple inflammatory response genes and an activated NF‐kB target pathway. Careful analysis of the interfollicular epidermis showed aberrant expression of the lamin B receptor (LBR) in the suprabasal layer. Prolonged expression of LBR, in 14.06% of the cells, likely contributes to the observed arrest of skin development, clearly evident at PD4 when the skin had developed into single‐layer epithelium in the wild‐type animals while progeroid animals still had the multilayered appearance typical for skin at PD3. Suprabasal cells expressing LBR showed altered DNA distribution, suggesting the induction of gene expression changes. Despite the formation of a functional epidermal barrier and proven functionality of the gap junctions, progeroid animals displayed a greater rate of water loss as compared with wild‐type littermates and died within the first two postnatal weeks.     

Influence of light and kairomone baiting systems on trap collections of biting midges in southern Sweden

Effective surveillance is essential for protecting livestock from Culicoides biting midges and the viruses they transmit. The objective of this study was to determine how the baiting system used in traps (UV, incandescent light, incandescent light with CO₂, and incandescent light with CO₂ and 1‐octen‐3‐ol) influences estimates of midge population abundance, parity, and diel activity. This was achieved through a standardized trapping protocol conducted in three habitats in Sweden. UV light traps caught the most Culicoides species and more C. obsoletus complex females than incandescent light traps. Traps baited with CO₂ plus 1‐octen‐3‐ol caught more female C. impunctatus than incandescent light traps. No consistent effect of bait type was found on C. obsoletus parity rate, as estimated from the proportion of midges with presence or absence of pigmentation. Midge activity, as reflected by trap catches, peaked between ‐3 h and +3 h relative to sunset, with UV traps catching significantly more female C. obsoletus complex and C. impunctatus at and after sunset than before sunset. We conclude that baiting system can influence biting midge collections, even using identical traps. Effective surveillance may require more than one bait type and kairomones to attract species that do not feed exclusively on cattle.     

Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume

We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training ( approximately 45 km/wk) with frequent high-intensity sessions each consisting of 8-12 30-s sprint runs separated by 3 min of rest (5.7 +/- 0.1 km/wk) with additional 9.9 +/- 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower (P < 0.05) at running speeds of 11, 13, 14.5, and 16 km/h, respectively, in SET, whereas remained the same in Con. No changes in blood lactate during submaximal running were observed. After the IT period, the protein expression of skeletal muscle UCP3 tended to be higher in SET (34 +/- 6 vs. 47 +/- 7 arbitrary units; P = 0.06). Activity of muscle citrate synthase and 3-hydroxyacyl-CoA dehydrogenase, as well as maximal oxygen uptake and 10-km performance time, remained unaltered in both groups. In SET, the capillary-to-fiber ratio was the same before and after the IT period. The present study showed that speed endurance training reduces energy expenditure during submaximal exercise, which is not mediated by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training.     

Impact of Prior Traumatic Life Events on Parental Early Stage Reactions following a Child's Cancer

Background

In pediatric oncology, effective clinic–based management of acute and long–term distress in families calls for investigation of determinants of parents'' psychological response to the child''s cancer. We examined the relationship between parents'' prior exposure to traumatic life events (TLE) and the occurrence of posttraumatic stress symptoms (PTSS) following their child''s cancer diagnosis. Factors mediating the TLE–PTSS relationship were analyzed.

Methodology

The study comprised 169 parents (97 mothers, 72 fathers) of 103 cancer diagnosed children (median age: 5,9 years; range 0.1–19.7 years). Thirty five parents were of immigrant origin (20.7%). Prior TLE were collated using a standardized questionnaire, PTSS was assessed using the Impact of Events–Revised (IES–R) questionnaire covering intrusion, avoidance and hyperarousal symptoms. The predictive significance of prior TLE on PTSS was tested in adjusted regression models.

Results

Mothers demonstrated more severe PTSS across all symptom dimensions. TLE were associated with significantly increased hyperarousal symptoms. Parents'' gender, age and immigrant status did not significantly influence the TLE–PTSS relationship.

Conclusions

Prior traumatic life–events aggravate posttraumatic hyperarousal symptoms. In clinic–based psychological care of parents of high–risk pediatric patients, attention needs to be paid to life history, and to heightened vulnerability to PTSS associated with female gender.     

Adenosine A 2B receptors modulate cAMP levels and induce CREB but not ERK1/2 and p38 phosphorylation in rat skeletal muscle cells

The present study examined the existence of the adenosine A(1),A(2A), and A(2B) receptors and the effect of receptor activation on cAMP accumulation and protein phosphorylation in primary rat skeletal muscle cells. Presence of mRNA and protein for all three receptors was demonstrated in both cultured and adult rat skeletal muscle. NECA (10(-9)-10(-4)M) increased the cAMP concentration in cultured muscle cells with an EC(50) of (95% confidence interval)=15 (5.9-25.1) micro M, whereas CGS 21680 (10(-9)-10(-4)M) had no effect on cAMP accumulation. Concentrations of [R]-PIA below 10(-6)M had no effect on cAMP accumulation induced by either isoproterenol or forskolin. NECA resulted in phosphorylation of CREB with an EC(50) of (95% confidence interval)=1.7 (0.40-7.02) micro M, whereas ERK1/2 and p38 phosphorylation was unchanged. The results show that, although the A(1),A(2A), and A(2B) receptors are all present in skeletal muscle cells, the effect of adenosine on adenylyl cyclase activation and phosphorylation of CREB is mainly mediated via the adenosine A(2B) receptor.