Crystal structure of TtgV in complex with its DNA operator reveals a general model for cooperative DNA binding of tetrameric gene regulators.

The majority of bacterial gene regulators bind as symmetric dimers to palindromic DNA operators of 12-20 base pairs (bp). Multimeric forms of proteins, including tetramers, are able to recognize longer operator sequences in a cooperative manner, although how this is achieved is not well understood due to the lack of complete structural information. Models, instead of structures, of complete tetrameric assembly on DNA exist in literature.

Predictors of parental risk perceptions: the case of child pedestrian injuries in school context.

The objective of this article is to explore the factors that influence parental risk perceptions of child pedestrian injuries in the elementary school context. Parents (n=193) from six different schools responded to a questionnaire on road safety, including a measure of their risk perception. Results of bivariate analyses show that eight variables are significantly related to risk perception.

Influence of Physical Activity Participation on the Associations between Eating Behaviour Traits and Body Mass Index in Healthy Postmenopausal Women.

Available data reveals inconsistent relationships between eating behaviour traits and markers of adiposity level. It is thus relevant to investigate whether other factors also need to be considered when interpreting the relationship between eating behaviour traits and adiposity. The objective of this cross-sectional study was thus to examine whether the associations between variables of the Three-Factor Eating Questionnaire (TFEQ) and adiposity are influenced by the level of physical activity participation.

Mass spectrometry in high-throughput proteomics: ready for the big time.

Mass spectrometry has evolved and matured to a level where it is able to assess the complexity of the human proteome. We discuss some of the expected challenges ahead and promising strategies for success.

Relationship of mid-thigh adiposity to the metabolic syndrome in postmenopausal women.

Background: In postmenopausal women, a population at risk for the metabolic syndrome, the relative contribution of central fat versus peripheral muscle fat to the metabolic risk profile is unknown. This study explored the relationship between muscle fat infiltration derived from computed tomography (CT) scans and metabolic syndrome.

Methods: Mid-thigh CT scans measured the surface of muscle with low attenuation (LAMS) [0-34 Hounsfield units (HU)], which represented the specific component of fat-rich muscle.

Exogenous fms-like tyrosine kinase 3 ligand overrides brain immune privilege and facilitates recognition of a neo-antigen without causing autoimmune neuropathology.

Soluble antigens diffuse out of the brain and can thus stimulate a systemic immune response, whereas particulate antigens (from infectious agents or tumor cells) remain within brain tissue, thus failing to stimulate a systemic immune response. Immune privilege describes how the immune system responds to particulate antigens localized selectively within the brain parenchyma. We believe this immune privilege is caused by the absence of antigen presenting dendritic cells from the brain.

Development and description of GETT: a genetic testing evidence tracking tool.

Background: The completion of the Human Genome Project has increased the pace of discovery of genetic markers for disease. Despite tremendous efforts in fundamental research, clinical applications still lag behind expectations, partly due to the lack of effective tools to systematically search for and summarize published data relative to the clinical assessment of new diagnostic molecular tests.

Methods: Through a collaborative process using published tools and an expert panel, we developed a detailed checklist of the evidence that needs to be collected or produced to evaluate the potential usefulness of a new molecular diagnostic test.

Rationalisation of the differences between APOBEC3G structures from crystallography and NMR studies by molecular dynamics simulations.

The human APOBEC3G (A3G) protein is a cellular polynucleotide cytidine deaminase that acts as a host restriction factor of retroviruses, including HIV-1 and various transposable elements. Recently, three NMR and two crystal structures of the catalytic deaminase domain of A3G have been reported, but these are in disagreement over the conformation of a terminal beta-strand, beta2, as well as the identification of a putative DNA binding site. We here report molecular dynamics simulations with all of the solved A3G catalytic domain structures, taking into account solubility enhancing mutations that were introduced during derivation of three out of the five structures.

Structural insights into serine-rich fimbriae from Gram-positive bacteria.

The serine-rich repeat family of fimbriae play important roles in the pathogenesis of streptococci and staphylococci. Despite recent attention, their finer structural details and precise adhesion mechanisms have yet to be determined. Fap1 (Fimbriae-associated protein 1) is the major structural subunit of serine-rich repeat fimbriae from Streptococcus parasanguinis and plays an essential role in fimbrial biogenesis, adhesion, and the early stages of dental plaque formation.

The SOCS-box of HIV-1 Vif interacts with ElonginBC by induced-folding to recruit its Cul5-containing ubiquitin ligase complex.

The HIV-1 viral infectivity factor (Vif) protein recruits an E3 ubiquitin ligase complex, comprising the cellular proteins elongin B and C (EloBC), cullin 5 (Cul5) and RING-box 2 (Rbx2), to the anti-viral proteins APOBEC3G (A3G) and APOBEC3F (A3F) and induces their polyubiquitination and proteasomal degradation. In this study, we used purified proteins and direct in vitro binding assays, isothermal titration calorimetry and NMR spectroscopy to describe the molecular mechanism for assembly of the Vif-EloBC ternary complex. We demonstrate that Vif binds to EloBC in two locations, and that both interactions induce structural changes in the SOCS box of Vif as well as EloBC.

Protein quality control in the ER: the recognition of misfolded proteins.

The mechanism, in molecular terms of protein quality control, specifically of how the cell recognizes and discriminates misfolded proteins, remains a challenge. In the secretory pathway the folding status of glycoproteins passing through the endoplasmic reticulum is marked by the composition of the N-glycan. The different glycoforms are recognized by specialized lectins.

Cell biology through proteomics--ad astra per alia porci.

Isolated subcellular fractions have been instrumental in elucidating cell function. The use of such fractions for the identification and biochemical characterization of subcellular organelles, combined with cell- free systems, has provided key insights into the function and machineries of organelles, including those involved in vesicle transport, quality control and protein sorting. Despite their obvious utility, popular cell biology has come to regard in vitro-based approaches as inferior to in vivo-based approaches.

Plasma adiponectin concentration is strongly associated with VLDL-TG catabolism in postmenopausal women.

Background And Aims: To investigate associations between plasma adiponectin concentration and very-low density lipoprotein-triglyceride (VLDL-TG) secretion and catabolism in postmenopausal women.

Methods And Results: This cross-sectional study included 30 postmenopausal women. Plasma adiponectin concentration was measured by ELISA.

AMPK-mediated phosphorylation of murine p27 at T197 promotes binding of 14-3-3 proteins and increases p27 stability.

The tuberous sclerosis complex 2 (Tsc2) gene product, tuberin, acts as a negative regulator of mTOR signaling, and loss of tuberin function leads to tumors of the brain, skin, kidney, heart, and lungs. Previous studies have shown that loss of tuberin function affects the stability and subcellular localization of the cyclin-dependent kinase inhibitor (CKI) p27, although the mechanism(s) by which tuberin modulates p27 stability has/have not been elucidated. Previous studies have also shown that AMP-activated protein kinase (AMPK), which functions in an energy-sensing pathway in the cell, becomes activated in the absence of tuberin.

Contribution of genetic and metabolic syndrome to omental adipose tissue PAI-1 gene mRNA and plasma levels in obesity.

Background: Plasminogen activator inhibitor type-1 (PAI-1) has already been associated with atherosclerosis; myocardial infarction; and cardiovascular disease risk factors such as obesity, insulin resistance, and dyslipidemia. However, factors regulating PAI-1 adipose tissue (AT) gene expression and plasma levels are not yet well defined.

Aim: This study aims to assess the contribution of PAI-1 omental AT mRNA levels and genetic and metabolic factors to variation in plasma PAI-1 concentrations.

Calnexin phosphorylation: linking cytoplasmic signalling to endoplasmic reticulum lumenal functions.

Calnexin is an abundant integral membrane phosphoprotein of the endoplasmic reticulum (ER) of eukaryotic cells. The role of the luminal domain as an N-glycoprotein specific lectin has been well-established. Cytosolic C-terminal domain phosphorylation of calnexin has recently been elucidated in glycoprotein folding and quality control.

Discordances among different tools used to estimate cardiovascular risk in postmenopausal women.

Background: New cardiovascular disease (CVD) risk factors are being recognized and suggested to be included in CVD risk stratification. High-sensitivity C-reactive protein (hs-CRP) and the metabolic syndrome (MetS) are among these risk factors. However, CVD risk classification may be divergent when using different approaches.

Assessment of the validity of the frequently used lipid indices for predicting LDL peak particle diameter in a large cohort of 1955 normal and dyslipidemic subjects.

Objectives: To assess the relationship between commonly used lipid indices and LDL peak particle diameter (LDL-PPD) in a large cohort of 1955 subjects.

Design And Methods: Four statistical methods were used for comparison: correlation, concordance analysis, kappa statistics and receiver operating characteristic curve (ROC) analysis.

Results: Plasma triglyceride (TG) levels, TG/HDL-C, LDL-C/apoB, total cholesterol (TC)/TG, LDL-C/TG, and TG/apoB ratios were best correlated with LDL-PPD but none of these ratios accounted for more than 45% of the variation in LDL-PPD.

Sorting out glycosylation enzymes in the Golgi apparatus.

The study of glycosylation and glycosylation enzymes has been instrumental for the advancement of Cell Biology. After Neutra and Leblond showed that the Golgi apparatus is the main site of glycosylation, elucidation of oligosaccharide structures by Baenziger and Kornfeld and subsequent mapping of glycosylation enzymes followed. This enabled development of anin vitrotransport assay by Rothman and co-workers using glycosylation to monitor intra Golgi transport which, complemented by yeast genetics by Schekman and co-workers, provided much of the fundamental insights and key components of the secretory pathway that we today take for granted.

Calnexin phosphorylation attenuates the release of partially misfolded alpha1-antitrypsin to the secretory pathway.

Calnexin is a type I integral membrane phosphoprotein resident of the endoplasmic reticulum. Its intraluminal domain has been deduced to function as a lectin chaperone coordinating the timing of folding of newly synthesized N-linked glycoproteins of the secretory pathway. Its C-terminal cytosolic oriented extension has an ERK1 phosphorylation site at Ser(563) affecting calnexin association with the translocon.

Plasma soluble tumour necrosis factor-alpha receptor 2 is elevated in obesity: specific contribution of visceral adiposity.

Objective: We examined the obesity phenotype most strongly associated with increased plasma concentrations of sTNFR2, and compared which of the two markers, TNF-alpha or sTNFR2, better predicts indices of plasma glucose-insulin homeostasis.

Design, Patients And Measurements: Plasma sTNFR2 levels were measured in a sample of 287 healthy nondiabetic men [age: 43.9 +/- 8.

Sex differences in postprandial plasma tumor necrosis factor-alpha, interleukin-6, and C-reactive protein concentrations.

Abdominal obesity and insulin resistance are characterized by low-level chronic inflammation most likely implicated in the increased cardiovascular disease risk associated with these conditions. However, not much is known of the acute regulation of circulating inflammatory markers in response to food intake. The aim of this study is to examine changes in inflammatory marker concentrations after the consumption of a high-fat meal in men and women.

Impact of a lignan-rich diet on adiposity and insulin sensitivity in post-menopausal women.

There has been a growing interest in lignans, a class of phyto-oestrogens, because of their potentially favourable effects on human health. The aim of the present study was to compare the metabolic profile of post-menopausal women consuming various amounts of dietary lignans. Phyto-oestrogen intake was assessed using a 3-d dietary record analysed with a Canadian food phyto-oestrogen content data table in 115 post-menopausal women (age 56.