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Wilson R Tavares, Ana M L Seca
Background: Plants and their derived natural compounds possess various biological and therapeutic properties, which turns them into an increasing topic of interest and research. Juniperus genus is diverse in species, with several traditional medicines reported, and rich in natural compounds with potential for development of new drugs. Methods: The research for this review were based in the Scopus and Web of Science databases using terms combining Juniperus , secondary metabolites names, and biological activities...
July 31, 2018: Medicines (Basel, Switzerland)
Imen Nouioui, Faten Ghodhbane-Gtari, Marlen Jando, Louis S Tisa, Hans-Peter Klenk, Maher Gtari
Strain CpI1T was, in 1978, the first isolate of the genus Frankia to be obtained from Comptonia peregrina root nodules. In this study, a polyphasic approach was performed to identify the taxonomic position of strain CpI1T among the members of the genus Frankia. The strain contains meso-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, mannose, rhamnose, ribose and xylose as cell wall sugars. The polar lipids were found to consist of phosphatidylinositol, diphosphatidylglycerol, glycophospholipids, phosphatidylglycerol, an aminophospholipid and unidentified phospholipids and lipids...
July 20, 2018: Antonie Van Leeuwenhoek
Robin A Corey, Euan Pyle, William J Allen, Daniel W Watkins, Marina Casiraghi, Bruno Miroux, Ignacio Arechaga, Argyris Politis, Ian Collinson
The transport of proteins across or into membranes is a vital biological process, achieved in every cell by the conserved Sec machinery. In bacteria, SecYEG combines with the SecA motor protein for secretion of preproteins across the plasma membrane, powered by ATP hydrolysis and the transmembrane proton-motive force (PMF). The activities of SecYEG and SecA are modulated by membrane lipids, particularly cardiolipin (CL), a specialized phospholipid known to associate with a range of energy-transducing machines...
July 31, 2018: Proceedings of the National Academy of Sciences of the United States of America
Ana M L Seca, Diana C G A Pinto
Hypertension and obesity are two significant factors that contribute to the onset and exacerbation of a cascade of mechanisms including activation of the sympathetic and renin-angiotensin systems, oxidative stress, release of inflammatory mediators, increase of adipogenesis and thus promotion of systemic dysfunction that leads to clinical manifestations of cardiovascular diseases. Seaweeds, in addition to their use as food, are now unanimously acknowledged as an invaluable source of new natural products that may hold noteworthy leads for future drug discovery and development, including in the prevention and/or treatment of the cardiovascular risk factors...
July 14, 2018: Marine Drugs
Jinshan Jin, Ying-Hsin Hsieh, Arpana S Chaudhary, Jianmei Cui, John E Houghton, Sen-Fang Sui, Binghe Wang, Phang C Tai
Sec-dependent protein translocation is an essential process in bacteria. SecA is a key component of the translocation machinery and has multiple domains that interact with various ligands. SecA acts as an ATPase motor to drive the precursor protein/peptide through the SecYEG protein translocation channels. As SecA is unique to bacteria and there is no mammalian counterpart, it is an ideal target for the development of new antimicrobials. Several reviews detail the assays for ATPase and protein translocation, as well as the search for SecA inhibitors...
August 1, 2018: FEMS Microbiology Letters
Donna E Fernandez
Chloroplasts inherited systems and strategies for protein targeting, translocation, and integration from their cyanobacterial ancestor. Unlike cyanobacteria however, chloroplasts in green algae and plants contain two distinct SEC translocase/integrase systems: the SEC1 system in the thylakoid membrane and the SEC2 system in the inner envelope membrane. This review summarizes the mode of action of SEC translocases, identification of components of the SEC2 system, evolutionary history of SCY and SECA genes, and previous work on the co- and post-translational targeting of lumenal and thylakoid membrane proteins to the SEC1 system...
June 27, 2018: Photosynthesis Research
Alfred Königsrainer, Silke Templin, Ivan Capobianco, Ingmar Königsrainer, Michael Bitzer, Lars Zender, Bence Sipos, Lothar Kanz, Silvia Wagner, Silvio Nadalin
OBJECTIVE: to report the first case of resection and partial liver segment 2-3 transplantation with delayed total hepatectomy (RAPID) from living donor in a patient affected of irresectable colorectal liver metastases (i-CRLM) BACKGROUND:: A renaissance of liver transplantation (LT) for i-CRLM has been recently observed. The Norwegian SECA trial demonstrated a 5-year overall survival rate of approximately 60%, notwithstanding early tumor recurrence. The RAPID technique was recently introduced as alternative to whole deceased donor LT, but it is limited by poor availability of splittable organs and many organisational aspects...
June 18, 2018: Annals of Surgery
Konstantina Karathanou, Ana-Nicoleta Bondar
The Sec protein secretion machinery includes proteins whose reaction coordinates involve large-scale conformational changes. Dynamic hydrogen-bond networks can provide structural plasticity required by the SecA protein motor and the SecY protein translocon. Here we discuss hydrogen-bond networks of these two Sec proteins from crystal structures and molecular simulations, and the usefulness of molecular simulations approaches to studying dynamic hydrogen bonds and their role in bacterial protein secretion.
July 1, 2018: FEMS Microbiology Letters
Zhilu Yang, Ying Yang, Li Zhang, Kaiqin Xiong, Xiangyang Li, Feng Zhang, Jin Wang, Xin Zhao, Nan Huang
The development of a nitric oxide (NO)-generating surface with long-term, stable and controllable NO release improves the therapeutic efficacy of cardiovascular stents. In this work, we developed a "one-pot" method inspired by mussel adhesive proteins for copolymerization of selenocystamine (SeCA) and dopamine (Dopa) to form a NO-generating coating on a 316 L stainless steel (SS) stent. This "one-pot" method is environmentally friendly and easy to popularize, with many advantages including simple manufacturing procedure, high stability and no involvement of organic solvents...
June 7, 2018: Biomaterials
Tomas Fessl, Daniel Watkins, Peter Oatley, William John Allen, Robin Adam Corey, Jim Horne, Steve A Baldwin, Sheena E Radford, Ian Collinson, Roman Tuma
Protein translocation across cell membranes is a ubiquitous process required for protein secretion and membrane protein insertion. In bacteria, this is mostly mediated by the conserved SecYEG complex, driven through rounds of ATP hydrolysis by the cytoplasmic SecA, and the trans-membrane proton motive force. We have used single molecule techniques to explore SecY pore dynamics on multiple timescales in order to dissect the complex reaction pathway. The results show that SecA, both the signal sequence and mature components of the pre-protein, and ATP hydrolysis each have important and specific roles in channel unlocking, opening and priming for transport...
June 7, 2018: ELife
Koreaki Ito, Hiroyuki Mori, Shinobu Chiba
Protein localization machinery supports cell survival and physiology, suggesting the potential importance of its expression regulation. Here, we summarize a remarkable scheme of regulation, which allows real-time feedback regulation of the machinery expression. A class of regulatory nascent polypeptides, called monitoring substrates, undergoes force-sensitive translation arrest. The resulting ribosome stalling on the mRNA then affects mRNA folding to expose the ribosome-binding site of the downstream target gene and upregulate its translation...
June 1, 2018: FEMS Microbiology Letters
Tamar Cranford-Smith, Damon Huber
In bacteria, translocation of most soluble secreted proteins (and outer membrane proteins in Gram-negative bacteria) across the cytoplasmic membrane by the Sec machinery is mediated by the essential ATPase SecA. At its core, this machinery consists of SecA and the integral membrane proteins SecYEG, which form a protein conducting channel in the membrane. Proteins are recognised by the Sec machinery by virtue of an internally encoded targeting signal, which usually takes the form of an N-terminal signal sequence...
June 1, 2018: FEMS Microbiology Letters
Ruth Steinberg, Lara Knüpffer, Andrea Origi, Rossella Asti, Hans-Georg Koch
About 30% of all bacterial proteins execute their function outside of the cytosol and have to be transported into or across the cytoplasmic membrane. Bacteria use multiple protein transport systems in parallel, but the majority of proteins engage two distinct targeting systems. One is the co-translational targeting by two universally conserved GTPases, the signal recognition particle (SRP) and its receptor FtsY, which deliver inner membrane proteins to either the SecYEG translocon or the YidC insertase for membrane insertion...
June 1, 2018: FEMS Microbiology Letters
Dereje Yohannes Teferi, Gudina Egata Atomssa, Tefera Chane Mekonnen
Background: This study aimed to assess the prevalence of malnutrition and associated factors among school adolescents in Wolaita Sodo town, Southern Ethiopia. Methods: A school-based cross-sectional study was conducted from May 18-June 10, 2015. A multistage sampling was used to select a random sample of 690 adolescents from selected schools. Data on sociodemographic information were collected by using an interviewer-administered questionnaire, and anthropometric measurements were made by using a digital Seca scale and height measuring board by trained data collectors...
2018: Journal of Nutrition and Metabolism
Pavol Skubák, Demet Araç, Matthew W Bowler, Ana R Correia, Andre Hoelz, Sine Larsen, Gordon A Leonard, Andrew A McCarthy, Sean McSweeney, Christoph Mueller-Dieckmann, Harm Otten, Gabriel Salzman, Navraj S Pannu
Determining macromolecular structures from X-ray data with resolution worse than 3 Å remains a challenge. Even if a related starting model is available, its incompleteness or its bias together with a low observation-to-parameter ratio can render the process unsuccessful or very time-consuming. Yet, many biologically important macromolecules, especially large macromolecular assemblies, membrane proteins and receptors, tend to provide crystals that diffract to low resolution. A new algorithm to tackle this problem is presented that uses a multivariate function to simultaneously exploit information from both an initial partial model and low-resolution single-wavelength anomalous diffraction data...
March 1, 2018: IUCrJ
Wenqi Yu, Dominique Missiakas, Olaf Schneewind
Surface proteins of Staphylococcus aureus are secreted across septal membranes for assembly into the bacterial cross-wall. This localized secretion requires the YSIRK/GXXS motif signal peptide, however the mechanisms supporting precursor trafficking are not known. We show here that the signal peptide of staphylococcal protein A (SpA) is cleaved at the YSIRK/GXXS motif. A SpA signal peptide mutant defective for YSIRK/GXXS cleavage is also impaired for septal secretion and co-purifies with SecA, SecDF and LtaS...
May 14, 2018: ELife
Tomoya Tsukazaki
The bacterial membrane protein SecDF enhances protein translocation across the membrane driven by the complex of SecA ATPase and SecYEG. Many newly synthesized proteins in the cytoplasm are programmed to be translocated to the periplasm via the narrow channel that is formed in the center of SecYEG. During the protein-translocation process, SecDF is proposed to undergo repeated conformational transitions to pull out the precursor protein from the SecYEG channel into the periplasm. Once SecDF captures the precursor protein on the periplasmic surface, SecDF can complete protein translocation even if SecA function is inactivated by ATP depletion, implying that SecDF is a protein-translocation motor that works independent of SecA...
June 1, 2018: FEMS Microbiology Letters
Sarah Freitas Magalhães, Sofia Calvo-Rodriguez, Mário Marcos do Espírito Santo, Gerardo Arturo Sánchez Azofeifa
Vegetation indices are useful tools to remotely estimate several important parameters related to ecosystem functioning. However, improving and validating estimations for a wide range of vegetation types are necessary. In this study, we provide a methodology for the estimation of the leaf area index (LAI) in a tropical dry forest (TDF) using the light diffusion through the canopy as a function of the successional stage. For this purpose, we estimated the K coefficient, a parameter that relates the normalized difference vegetation index (NDVI) to LAI, based on photosynthetically active radiation (PAR) and solar radiation...
July 2018: International Journal of Biometeorology
S Dueland, A Foss, J M Solheim, M Hagness, P-D Line
BACKGROUND: Liver transplantation is considered the standard of care for patients with hepatocellular carcinoma (HCC) within the Milan criteria. Liver transplantation in patients with unresectable colorectal cancer with liver-only disease has been shown to be associated with a 5-year overall survival rate of 56 per cent, compared with 9 per cent in patients receiving standard palliative chemotherapy. The aim of the present study was to compare disease-free (DFS) and overall (OS) survival after liver transplantation in patients with HCC and those with colorectal metastases...
May 2018: British Journal of Surgery
Jade L L Teng, Ying Tang, Samson S Y Wong, Tsz Ho Chiu, Zhe Zhao, Elaine Chan, Antonio H Y Ngan, Susanna K P Lau, Patrick C Y Woo
Three bacterial strains, HKU63T , HKU64 and HKU65T , were isolated from the conjunctival swabs of three patients with conjunctivitis in Hong Kong. The three strains were aerobic, Gram-stain-positive, catalase-positive, non-sporulating and non-motile bacilli and exhibited unique biochemical profiles distinguishable from closely related Tsukamurella species. 16S rRNA gene sequence analysis revealed that the three strains shared identical sequences with each other, being most closely related to Tsukamurella tyrosinosolvens and Tsukamurella pulmonis, sharing 99...
March 2018: International Journal of Systematic and Evolutionary Microbiology
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