Read by QxMD icon Read

Point mutation

Hüseyin Ilgü, Jean-Marc Jeckelmann, Claire Colas, Zöhre Ucurum, Avner Schlessinger, Dimitrios Fotiadis
The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures ( T m s) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide...
March 20, 2018: International Journal of Molecular Sciences
Li Bao, Zhaoyang Qian, Maria B Lyng, Ling Wang, Yuan Yu, Ting Wang, Xiuqing Zhang, Huanming Yang, Nils Brünner, Jun Wang, Henrik J Ditzel
Single cancer cell sequencing studies currently use randomly-selected cells, limiting correlations between genomic aberrations, morphology and spatial localization. We laser-captured microdissected single cells from morphologically-distinct areas of primary breast cancer and corresponding lymph node metastasis and performed whole-exome or deep-target sequencing of greater than 100 such cells. Two major subclones co-existed in different areas of the primary tumor, and the lymph node metastasis originated from a minor subclone in the invasive front of the primary tumor with additional copy number changes including 8q gain, but no additional point mutations in driver genes...
March 15, 2018: Journal of Clinical Investigation
Chuang Qu, Shuhui Gao, Hongwei Shao, Wenfeng Zhang, Huabben Bo, Xin Lu, Tianjiao Chen, Jing Kou, Yue Wang, Gui Si Chen, Shulin Huang, Han Shen
Cluster of differentiation (CD)147 is highly expressed in drug-resistant tumor cell lines and is involved in the formation of tumor drug resistance. Therefore, immunotherapy utilizing CD147 epitope peptides is a promising approach for the elimination of drug-resistant tumor cells. However, like most tumor-associated antigens (TAAs), CD147 belongs to the autoantigen category, and T cells that recognize high affinity, immunodominant epitopes from autoantigens are deleted though thymic negative selection. Furthermore, wild-type autoantigen peptides cannot effectively activate and expand T lymphocytes with lower affinity T cell receptors in vivo ...
April 2018: Oncology Letters
Tom Verbiest, Rosemary Finnon, Natalie Brown, Lourdes Cruz-Garcia, Paul Finnon, Grainne O'Brien, Eleanor Ross, Simon Bouffler, Cheryl L Scudamore, Christophe Badie
Epidemiological studies have demonstrated an increased leukemia incidence following ionizing radiation exposure, but to date, the target cells and underlying mechanisms of radiation leukemogenesis remain largely unidentified. We engineered a mouse model carrying a different fluorescent marker on each chromosome 2, located inside the minimum deleted region occurring after radiation exposure and recognized as the first leukemogenic event. Using this tailored model, we report that following radiation exposure, more than half of asymptomatic CBA Sfpi1 GFP/mCh mice presented with expanding clones of preleukemic hematopoietic cells harboring a hemizygous interstitial deletion of chromosome 2...
March 3, 2018: Leukemia: Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K
J Montag, B Petersen, A K Flögel, E Becker, A Lucas-Hahn, G J Cost, C Mühlfeld, T Kraft, H Niemann, B Brenner
Familial Hypertrophic Cardiomyopathy (HCM) is the most common inherited cardiac disease. About 30% of the patients are heterozygous for mutations in the MYH7 gene encoding the ß-myosin heavy chain (MyHC). Hallmarks of HCM are cardiomyocyte disarray and hypertrophy of the left ventricle, the symptoms range from slight arrhythmias to sudden cardiac death or heart failure. To gain insight into the underlying mechanisms of the diseases' etiology we aimed to generate genome edited pigs with an HCM-mutation. We used TALEN-mediated genome editing and successfully introduced the HCM-point mutation R723G into the MYH7 gene of porcine fibroblasts and subsequently cloned pigs that were heterozygous for the HCM-mutation R723G...
March 19, 2018: Scientific Reports
Maria Pardos de la Gandara, Vitor Borges, Marilyn Chung, Catarina Milheiriço, João Paulo Gomes, Herminia de Lencastre, Alexander Tomasz
Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications we identified genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC carrying MRSA strain LGA251...
March 19, 2018: Antimicrobial Agents and Chemotherapy
Suzanne Scheele, Jennifer A Geiger, Amy E DeRocher, Ryan Choi, Tess R Smith, Matthew A Hulverson, Rama Subba Rao Vidadala, Lynn K Barrett, Dustin J Maly, Ethan A Merritt, Kayode K Ojo, Wesley C Van Voorhis, Marilyn Parsons
In Toxoplasma gondii , calcium-dependent protein kinase 1 (CDPK1) is an essential protein kinase required for invasion of host cells. We have developed several hundred CDPK1 inhibitors, many of which block invasion. Inhibitors with similar IC50 s were tested in thermal shift assays for their ability to stabilize CDPK1 in cell lysates, in intact cells, or in purified form. Compounds that inhibited parasite growth stabilized CDPK1 in all assays. In contrast, two compounds that showed poor growth inhibition stabilized CDPK1 in lysates but not in cells...
March 19, 2018: Antimicrobial Agents and Chemotherapy
Ding Qian-Shan, Zhang Li, Wang Bi-Cheng, Zeng Zhi, Zou Xian-Qiong, Cao Peng-Bo, M S Zhou Guang-Ming, Tang Meng, Wu Lu, B S Wu Lian-Lian, Yu Hong-Gang, Guo Yong, Zhou Fu-Xiang
Microrchidia 2 (MORC2) plays important roles in DNA damage repair and lipogenesis, but the clinical and functional role of MORC2 in cancer remains largely unexplored. In this study, we showed that MORC2 was widely expressed in human tissues while significantly up-regulated in most cancer types employing immunohistochemical staining and analysis of mRNA expression profile of more than 2000 human tissue samples from 15 different organs (lung, prostate, liver, breast, brain, stomach, colon/rectum, pancreas, ovary, endometrium, skin, nasopharynx, kidney, oesophagus and bladder)...
March 16, 2018: Human Pathology
Waqas Ahmed, Maria Razzaq
Brucella spp. are facultative intracellular pathogens responsible for brucellosis, an emerging zoonosis that results in abortion, sterility in host animals, and chronic relapsing fever in humans. The small noncoding RNA (sRNA) AbcR is a textbook example of a molecule acting on trans-encoded target mRNAs, a principal element of bacterial gene regulation required for wild-type virulence in α-proteobacteria. Here, we used bioinformatics and experimental validation to characterize the interaction between AbcR sRNA and target mRNA...
March 16, 2018: Microbial Pathogenesis
Susanne Smaardijk, Jialin Chen, Sara Kerselaers, Thomas Voets, Jan Eggermont, Peter Vangheluwe
The Secretory Pathway Ca2+ ATPases SPCA1 and SPCA2 transport Ca2+ and Mn2+ into the Golgi and Secretory Pathway. SPCA2 mediates store-independent Ca2+ entry (SICE) via STIM1-independent activation of Orai1, inducing constitutive Ca2+ influx in mammary epithelial cells during lactation. Here, we show that like SPCA2, also the overexpression of the ubiquitous SPCA1 induces cytosolic Ca2+ influx, which is abolished by Orai1 knockdown and occurs independently of STIM1. This process elevates the Ca2+ concentration in the cytosol and in the non-endoplasmic reticulum (ER) stores, pointing to a functional coupling between Orai1 and SPCA1...
March 16, 2018: Biochimica et Biophysica Acta
Anton Khmelnitskiy, Rafael G Saer, Robert E Blankenship, Ryszard J Jankowiak
We report high-resolution (low-temperature) absorption, emission and nonresonant/resonant hole-burned (HB) spectra and results of excitonic calculations using a non-Markovian reduced density matrix theory (with an improved algorithm for parameter optimization in heterogeneous samples) obtained for the Y16F mutant of the Fenna-Matthews-Olson (FMO) trimer from the green sulfur bacterium Chlorobaculum tepidum. We show that the Y16F mutant is a mixture of FMO complexes with three independent low-energy traps (located near 817, 821, and 826 nm), in agreement with measured composite emission and HB spectra...
March 19, 2018: Journal of Physical Chemistry. B
Stefanie Gerson, Jennifer Nowak, Esther Zander, Julia Ertel, Yurong Wen, Oleg Krut, Harald Seifert, Paul G Higgins
Objectives: To investigate the mechanisms of tigecycline resistance in isogenic Acinetobacter baumannii isolate pairs as well as 65 unique clinical A. baumannii isolates obtained during the MagicBullet clinical trial from Greece, Italy and Spain. Methods: A. baumannii isolates were subjected to WGS and the regulatory genes of resistance-nodulation-cell division (RND)-type efflux pumps were analysed. MICs were determined by agar dilution and the expression of RND-type efflux pumps was measured by semi-quantitative RT-PCR...
March 14, 2018: Journal of Antimicrobial Chemotherapy
Kiem Vu, George R Thompson, Chandler C Roe, Jane E Sykes, Elizabeth M Dreibe, Shawn R Lockhart, Wieland Meyer, David M Engelthaler, Angie Gelli
Cryptococcosis is an opportunistic fungal infection caused by members of the two sibling species complexes: Cryptococcus neoformans and Cryptococcus gattii. Flucytosine (5FC) is one of the most widely used antifungals against Cryptococcus spp., yet very few studies have looked at the molecular mechanisms responsible for 5FC resistance in this pathogen. In this study, we examined 11 C. gattii clinical isolates of the major molecular type VGIII based on differential 5FC susceptibility and asked whether there were genomic changes in the key genes involved in flucytosine metabolism...
March 15, 2018: Medical Mycology: Official Publication of the International Society for Human and Animal Mycology
Candice Brinkmeyer-Langford, Candice Chu, Cynthia Balog-Alvarez, Xue Yu, James J Cai, Mary Nabity, Joe N Kornegay
Duchenne muscular dystrophy (DMD) causes progressive disability in 1 of every 5,000 boys due to the lack of functional dystrophin protein. Despite much advancement in knowledge about DMD disease presentation and progression-attributable in part to studies using mouse and canine models of the disease-current DMD treatments are not equally effective in all patients. There remains, therefore, a need for translational animal models in which novel treatment targets can be identified and evaluated. Golden Retriever muscular dystrophy (GRMD) is a phenotypically and genetically homologous animal model of DMD...
2018: PloS One
Xiao Yi
Biological functions - studied by molecular, systems and behavioral biology - are referred to as proximate mechanisms. Why and how they have emerged from the course of evolution are referred to as ultimate mechanisms. Despite the conceptual and technical schism between the disciplines that focus on each, studies from one side can benefit the other. Experimental evolution is an emerging field at the crossroads of functional and evolutionary biology. Herein microorganisms and mammalian cell lines evolve in well-controlled laboratory environments over multiple generations...
December 2017: Synthetic and Systems Biotechnology
Laurence Thielemans, Gornpan Gornsawun, Borimas Hanboonkunupakarn, Moo Kho Paw, Pen Porn, Paw Khu Moo, Bart Van Overmeire, Stephane Proux, François Nosten, Rose McGready, Verena I Carrara, Germana Bancone
Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited enzymatic disorder associated with severe neonatal hyperbilirubinemia and acute haemolysis after exposure to certain drugs or infections. The disorder can be diagnosed phenotypically with a fluorescent spot test (FST), which is a simple test that requires training and basic laboratory equipment. This study aimed to assess the diagnostic performances of the FST used on umbilical cord blood by locally-trained staff and to compare test results of the neonates at birth with the results after one month of age...
2018: Wellcome Open Research
Charlotte Spicher, Ruth Schneider, Peter Mönnings, Christiane Schneider-Gold, Dennis Kallenberg, Bilal Cevik, Carsten Lukas, Ralf Gold, Christos Krogias
Background: Duchenne muscular dystrophy (DMD) is an X-linked recessive skeletal muscle myopathy which is caused by mutations in the dystrophin gene. Lack of dystrophin also results to cardiomyopathy, which raises significantly the stroke risk in DMD-patients. However, data about therapeutic opportunities in the acute setting are scarce in literature. So far, only two cases receiving IV thrombolysis are described, one of them with fatal outcome. Method: Case report of a case of successful mechanical thrombectomy (MTE) in an acute ischemic stroke (AIS) patient with DMD and associated dilatative cardiomyopathy...
2018: Therapeutic Advances in Neurological Disorders
Marta Zamarbide, Adam W Oaks, Heather L Pond, Julia S Adelman, M Chiara Manzini
Hundreds of genes are mutated in non-syndromic intellectual disability (ID) and autism spectrum disorder (ASD), with each gene often involved in only a handful of cases. Such heterogeneity can be daunting, but rare recessive loss of function (LOF) mutations can be a good starting point to provide insight into the mechanisms of neurodevelopmental disease. Biallelic LOF mutations in the signaling scaffold CC2D1A cause a rare form of autosomal recessive ID, sometimes associated with ASD and seizures. In parallel, we recently reported that Cc2d1a -deficient mice present with cognitive and social deficits, hyperactivity and anxiety...
2018: Frontiers in Genetics
Svetlana A Semerikova, Yuliya Y Khrunyk, Martin Lascoux, Vladimir L Semerikov
The origin of conifer genera, the main components of mountain temperate and boreal forests, was deemed to arise in the Mesozoic, although paleontological records and molecular data point to a recent diversification, presumably related to Neogene cooling. The geographical area(s) where the modern lines of conifers emerged remains uncertain, as is the sequence of events leading to their present distribution. To gain further insights into the biogeography of firs (Abies), we conducted phylogenetic analyses of chloroplast, mitochondrial and nuclear markers...
March 15, 2018: Molecular Phylogenetics and Evolution
Seaim Lwin Aye, Kei Fujiwara, Asuka Ueki, Nobuhide Doi
Although compartmentalized self-replication (CSR) and compartmentalized partnered replication (CPR) are powerful tools for directed evolution of proteins and gene circuits, limitations remain in the emulsion PCR process with the wild-type Taq DNA polymerase used so far, including long run times, low amounts of product, and false negative results due to inhibitors. In this study, we developed a high-efficiency mutant of DNA polymerase I from Thermus thermophilus HB27 (Tth pol) suited for CSR and CPR. We modified the wild-type Tth pol by (i) deletion of the N-terminal 5' to 3' exonuclease domain, (ii) fusion with the DNA-binding protein Sso7d, (iii) introduction of four known effective point mutations from other DNA polymerase mutants, and (iv) codon optimization to reduce the GC content...
March 14, 2018: Biochemical and Biophysical Research Communications
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"