Read by QxMD icon Read


Niels Vandenberk, Spyridoula Karamanou, Athina G Portaliou, Valentina Zorzini, Johan Hofkens, Jelle Hendrix, Anastassios Economou
SecA converts ATP energy to protein translocation work. Together with the membrane-embedded SecY channel it forms the bacterial protein translocase. How secretory proteins bind to SecA and drive conformational cascades to promote their secretion remains unknown. To address this, we focus on the preprotein binding domain (PBD) of SecA. PBD crystalizes in three distinct states, swiveling around its narrow stem. Here, we examined whether PBD displays intrinsic dynamics in solution using single-molecule Förster resonance energy transfer (smFRET)...
October 29, 2018: Structure
Nagaraju Chada, Kanokporn Chattrakun, Brendan P Marsh, Chunfeng Mao, Priya Bariya, Gavin M King
SecA is the critical adenosine triphosphatase that drives preprotein transport through the translocon, SecYEG, in Escherichia coli . This process is thought to be regulated by conformational changes of specific domains of SecA, but real-time, real-space measurement of these changes is lacking. We use single-molecule atomic force microscopy (AFM) to visualize nucleotide-dependent conformations and conformational dynamics of SecA. Distinct topographical populations were observed in the presence of specific nucleotides...
October 2018: Science Advances
Djenisa H A Rocha, Ana M L Seca, Diana C G A Pinto
Isolation, finding or discovery of novel anticancer agents is very important for cancer treatment, and seaweeds are one of the largest producers of chemically active metabolites with valuable cytotoxic properties, and therefore can be used as new chemotherapeutic agents or source of inspiration to develop new ones. Identification of the more potent and selective anticancer components isolated from brown, green and red seaweeds, as well as studies of their mode of action is very attractive and constitute a small but relevant progress for pharmacological applications...
October 26, 2018: Marine Drugs
Axel Andres, Graziano Oldani, Thierry Berney, Philippe Compagnon, Pål-Dag Line, Christian Toso
Liver transplantation (LT) has become the standard of care for selected primary and secondary malignancies. Considered a contra-indication to transplantation until recently, unresectable colorectal liver metastases (CRLM) have gained interest since the publication of the SECA trial by the University of Oslo. It showed a 5-year overall survival of 60%, comparable to the one of standard transplant indication. This report generated multiple questions about the place of LT for CRLM and gave raise to several trials aiming at answering them...
2018: Translational Gastroenterology and Hepatology
Susana Seca, Miguel Patrício, Sebastian Kirch, Giovanna Franconi, António S Cabrita, Henry J Greten
BACKGROUND: Rheumatoid arthritis (RA) is characterized by pain, functional disability, poor quality of life (QoL), high socioeconomic impact, and annual costs of over $56 billion in the United States. Acupuncture (AC) is widely in use; however, studies show severe methodological shortcomings, did not consider the functional diagnosis for the allocation of acupoints and their results showed no differences between verum and control groups. OBJECTIVE: The authors aimed to objectively assess the safety and efficacy of AC treatments for RA...
October 16, 2018: Journal of Alternative and Complementary Medicine: Research on Paradigm, Practice, and Policy
Donald Oliver
Characterization of Sec-dependent bacterial protein transport has often relied on an in vitro protein translocation system comprised in part of E. coli inverted inner membrane vesicles or more recently purified SecYEG translocons reconstituted into liposomes using mostly a single substrate (proOmpA). A paper published in this issue of the Journal of Bacteriology (P. Bariya and L. Randall, J Bacteriol, this issue) finds that inclusion of SecA protein during SecYEG proteoliposome reconstitution dramatically improves the number of active translocons: both an experimentally useful and intriguing result that may arise from SecA membrane integration properties as discussed here...
October 15, 2018: Journal of Bacteriology
Kaitlin Day, Alastair Kwok, Alison Evans, Fernanda Mata, Antonio Verdejo-Garcia, Kathryn Hart, Leigh C Ward, Helen Truby
This study aimed to compare the use of the bioelectrical impedance device (BIA) seca® mBCA 515 using dual X-ray absorptiometry (DXA) as a reference method, for body composition assessment in adults across the spectrum of body mass indices. It explores the utility of simple anthropometric measures (the waist height ratio (WHtR) and waist circumference (WC)) for the assessment of obesity. In the morning after an overnight fast (10 h), 30 participants underwent a body composition DXA (GE iDXA) scan, BIA (seca 515), and anthropometric measures...
October 10, 2018: Nutrients
Min Ji Yeon, Min Ho Lee, Do Hyun Kim, Ji Yeong Yang, Hyun Jun Woo, Hye Jin Kwon, Cheol Moon, Sa-Hyun Kim, Jong-Bae Kim
Inflammation induced by Helicobacter pylori infection related to gastric carcinogenesis. In this study, we have investigated the anti-inflammatory effect and its mechanism of kaempferol in the inflammatory response caused by H. pylori infection in vitro. We found that kaempferol reduced the expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-8) and production of IL-8 in AGS cells. In addition, kaempferol suppressed translocation of cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) of H...
October 5, 2018: Bioscience, Biotechnology, and Biochemistry
Priya Bariya, Linda L Randall
In all cells a highly conserved channel transports proteins across membranes. In E.coli , that channel is SecYEG. Many investigations of this protein complex have used purified SecYEG reconstituted into proteoliposomes. How faithfully do activities of reconstituted systems reflect the properties of SecYEG in the native membrane environment? We investigated by comparing three in vitro systems: the native membrane environment of inner membrane vesicles and two methods of reconstitution. One method was the widely used reconstitution of SecYEG alone into lipid bilayers...
October 1, 2018: Journal of Bacteriology
Isabel Ernst, Maximilian Haase, Stefan Ernst, Shuguang Yuan, Andreas Kuhn, Sebastian Leptihn
SecA is an essential molecular motor for the translocation of proteins across the membrane via the bacterial Sec secretion system. While the Sec system is found in all cells from archaea to multicellular eukaryotes, the SecA protein is mainly found in bacteria. The mechanism of how the motor protein works on a molecular level is still under dispute but it is well established that SecA binds ATP and uses its hydrolysis for the translocation of substrates. In this work, we addressed the question of which conformational changes the protein might undergo during protein translocation...
2018: Communications biology
Venkata Raveendra Pothineni, Mansi B Parekh, Mustafeez Mujtaba Babar, Aditya Ambati, Peter Maguire, Mohammed Inayathullah, Kwang-Min Kim, Lobat Tayebi, Hari-Hara Sk Potula, Jayakumar Rajadas
Background: Lyme disease accounts for >90% of all vector-borne disease cases in the United States and affect ~300,000 persons annually in North America. Though traditional tetracycline antibiotic therapy is generally prescribed for Lyme disease, still 10%-20% of patients treated with current antibiotic therapy still show lingering symptoms. Methods: In order to identify new drugs, we have evaluated four cephalosporins as a therapeutic alternative to commonly used antibiotics for the treatment of Lyme disease by using microdilution techniques like minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC)...
2018: Drug Design, Development and Therapy
Katherine González-Ruíz, María Medrano, Jorge Enrique Correa-Bautista, Antonio García-Hermoso, Daniel Humberto Prieto-Benavides, Alejandra Tordecilla-Sanders, César Agostinis-Sobrinho, María Correa-Rodríguez, Jacqueline Schmidt Rio-Valle, Emilio González-Jiménez, Robinson Ramírez-Vélez
Dual-energy X-ray absorptiometry (DXA) has been considered a reference method for measuring body fat percentage (BF%) in children and adolescents with an excess of adiposity. However, given that the DXA technique is impractical for routine field use, there is a need to investigate other methods that can accurately determine BF%. We studied the accuracy of bioelectrical impedance analysis (BIA) technology, including foot-to-foot and hand-to-foot impedance, and Slaughter skinfold-thickness equations in the measurement of BF%, compared with DXA, in a population of Latin American children and adolescents with an excess of adiposity...
August 14, 2018: Nutrients
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...
December 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
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"