Mutation of the β1-tubulin gene associated with congenital macrothrombocytopenia affecting microtubule assembly

Blood ◽  
2009 ◽  
Vol 113 (2) ◽  
pp. 458-461 ◽  
Author(s):  
Shinji Kunishima ◽  
Ryoji Kobayashi ◽  
Tomohiko J. Itoh ◽  
Motohiro Hamaguchi ◽  
Hidehiko Saito
Keyword(s):  
Chinese Hamster ◽  
Microtubule Assembly ◽  
Nucleotide Polymorphism ◽  
Rare Disorders ◽  
Single Nucleotide ◽  
Normal Platelet ◽  
Peripheral Blood Cd34 ◽  
Cd34 Cells ◽  
In Vitro Transfection

Abstract Congenital macrothrombocytopenia is a genetically heterogeneous group of rare disorders. We identified the first TUBB1 mutation, R318W, in a patient with congenital macrothrombocytopenia. The patient was heterozygous for Q43P, but this single-nucleotide polymorphism (SNP) did not relate to macrothrombocytopenia. Although no abnormal platelet β1-tubulin localization/marginal band organization was observed, the level of β1-tubulin was decreased by approximately 50% compared with healthy controls. Large and irregular bleb protrusions observed in megakaryocytes derived from the patient's peripheral blood CD34+ cells suggested impaired megakaryocyte fragmentation and release of large platelets. In vitro transfection experiments in Chinese hamster ovary (CHO) cells demonstrated no incorporation of mutant β1-tubulin into microtubules, but the formation of punctuated insoluble aggregates. These results suggested that mutant protein is prone to aggregation but is unstable within megakaryocytes/platelets. Alternatively, mutant β1-tubulin may not be transported from the megakaryocytes into platelets. W318 β1-tubulin may interfere with normal platelet production, resulting in macrothrombocytopenia.

Successful transfer of ADA gene in vitro into human peripheral blood CD34+cells by transfecting EBV-based episomal vectors

FEBS Letters ◽  
1998 ◽  
Vol 441 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Etsuko Satoh ◽  
Hideyo Hirai ◽  
Tohru Inaba ◽  
Chihiro Shimazaki ◽  
Masao Nakagawa ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Peripheral Blood Cd34 ◽  
Cd34 Cells ◽  
Episomal Vectors ◽  
Successful Transfer

scholarly journals A Novel Single-Nucleotide Polymorphism Loop Mediated Isothermal Amplification Assay for Detection of Artemisinin-Resistant Plasmodium falciparum Malaria

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Abu Naser Mohon ◽  
Didier Menard ◽  
Mohammad Shafiul Alam ◽  
Kevin Perera ◽  
Dylan R Pillai
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Dynamic Range ◽  
Developed Countries ◽  
Isothermal Amplification ◽  
Test Method ◽  
Nucleotide Polymorphism ◽  
In Vitro Susceptibility ◽  
Single Nucleotide ◽  
Loop Mediated Isothermal Amplification

Abstract Background Artemisinin-resistant malaria (ARM) remains a significant threat to malaria elimination. In the Greater Mekong subregion, the prevalence of ARM in certain regions has reached greater than 90%. Artemisinin-resistant malaria is clinically identified by delayed parasite clearance and has been associated with mutations in the propeller domain of the kelch 13 gene. C580Y is the most prevalent mutation. The detection of ARM currently relies on labor-intensive and time-consuming methods such as clinical phenotyping or in vitro susceptibility testing. Methods We developed a novel single-nucleotide polymorphism loop mediated isothermal amplification (SNP-LAMP) test method for the detection of the C580Y mutation using a novel primer design strategy. Results The SNP-LAMP was 90.0% sensitive (95% confidence interval [CI], 66.9–98.3) and 91.9% specific (95% CI, 82.6–96.7) without knowledge of the parasite load and was 100% sensitive (95% CI, 79.9–100) and 97.3% specific (95% CI, 89.7–99.5) when the parasitemia was within the assay dynamic range. Tests with potential application near-to-patient such as SNP-LAMP may be deployed in low- and middle-income and developed countries. Conclusions Single-nucleotide polymorphism LAMP can serve as a surveillance tool and guide treatment algorithms for ARM in a clinically relevant time frame, prevent unnecessary use of additional drugs that may drive additional resistance, and avoid longer treatment regimens that cause toxicity for the patient.

scholarly journals Bottom-up single-molecule strategy for understanding subunit function of tetrameric β-galactosidase

2018 ◽  
Vol 115 (33) ◽  
pp. 8346-8351 ◽  
Author(s):  
Xiang Li ◽  
Yu Jiang ◽  
Shaorong Chong ◽  
David R. Walt
Keyword(s):  
Single Molecule ◽  
Wild Type ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Single Molecule Level ◽  
Subunit Function ◽  
Enzyme Molecules ◽  
Individual Enzyme ◽  
Kinetics Of

In this paper, we report an example of the engineered expression of tetrameric β-galactosidase (β-gal) containing varying numbers of active monomers. Specifically, by combining wild-type and single-nucleotide polymorphism plasmids at varying ratios, tetrameric β-gal was expressed in vitro with one to four active monomers. The kinetics of individual enzyme molecules revealed four distinct populations, corresponding to the number of active monomers in the enzyme. Using single-molecule-level enzyme kinetics, we were able to measure an accurate in vitro mistranslation frequency (5.8 × 10−4 per base). In addition, we studied the kinetics of the mistranslated β-gal at the single-molecule level.

scholarly journals Serotonin 5-HT2C Receptor Cys23Ser Single Nucleotide Polymorphism Associates with Receptor Function and Localization In Vitro

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Michelle A. Land ◽  
Holly L. Chapman ◽  
Brionna D. Davis-Reyes ◽  
Daniel E. Felsing ◽  
John A. Allen ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Subcellular Localization ◽  
Cell Lines ◽  
Intracellular Signaling ◽  
Calcium Release ◽  
Wild Type ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Recycling Pathway

Abstract A non-synonymous single nucleotide polymorphism of the human serotonin 5-HT2C receptor (5-HT2CR) gene that converts a cysteine to a serine at amino acid codon 23 (Cys23Ser) appears to impact 5-HT2CR pharmacology at a cellular and systems level. We hypothesized that the Cys23Ser alters 5-HT2CR intracellular signaling via changes in subcellular localization in vitro. Using cell lines stably expressing the wild-type Cys23 or the Ser23 variant, we show that 5-HT evokes intracellular calcium release with decreased potency and peak response in the Ser23 versus the Cys23 cell lines. Biochemical analyses demonstrated lower Ser23 5-HT2CR plasma membrane localization versus the Cys23 5-HT2CR. Subcellular localization studies demonstrated O-linked glycosylation of the Ser23 variant, but not the wild-type Cys23, may be a post-translational mechanism which alters its localization within the Golgi apparatus. Further, both the Cys23 and Ser23 5-HT2CR are present in the recycling pathway with the Ser23 variant having decreased colocalization with the early endosome versus the Cys23 allele. Agonism of the 5-HT2CR causes the Ser23 variant to exit the recycling pathway with no effect on the Cys23 allele. Taken together, the Ser23 variant exhibits a distinct pharmacological and subcellular localization profile versus the wild-type Cys23 allele, which could impact aspects of receptor pharmacology in individuals expressing the Cys23Ser SNP.

scholarly journals Single-Nucleotide-Polymorphism-Specific PCR for Quantification and Discrimination of Chlamydia pneumoniae Genotypes by Use of a “Locked” Nucleic Acid

2006 ◽  
Vol 72 (5) ◽  
pp. 3785-3787 ◽  
Author(s):  
Jan Rupp ◽  
Werner Solbach ◽  
Jens Gieffers
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Chlamydia Pneumoniae ◽  
Locked Nucleic Acid ◽  
Nucleotide Polymorphisms ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Specific Pcr ◽  
Intraspecies Diversity

ABSTRACT Single-nucleotide polymorphisms (SNPs) are targets to discriminate intraspecies diversity of bacteria and to correlate a genotype with a potential pathotype. Quantification of polygenotypic populations supports this task for in vitro and in vivo applications. We present a novel assay capable of quantifying mixtures of two genotypes differing by only one SNP.

scholarly journals A Novel Assay for Viral MicroRNA Function Identifies a Single Nucleotide Polymorphism That Affects Drosha Processing

2006 ◽  
Vol 80 (11) ◽  
pp. 5321-5326 ◽  
Author(s):  
Eva Gottwein ◽  
Xuezhong Cai ◽  
Bryan R. Cullen
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Target Genes ◽  
Human Herpesvirus ◽  
Northern Analysis ◽  
Luciferase Expression ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Stem Loop

ABSTRACT MicroRNAs (miRNAs) are a class of ∼22-nucleotide noncoding RNAs that inhibit the expression of specific target genes at the posttranscriptional level. Recently, 11 miRNAs encoded by the pathogenic human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) were cloned from latently infected cells. While the expression of these miRNAs has been confirmed by Northern analysis, their ability to inhibit target gene expression has not been demonstrated. We have devised a novel assay for miRNA function that uses lentiviral indicator vectors carrying two perfectly complementary target sites for each given miRNA in the 3′ untranslated region of the Renilla luciferase gene. This assay allowed us to demonstrate the activity of each viral miRNA upon cotransduction of cells with the Renilla luciferase indicator vector together with a firefly luciferase control vector. In KSHV-infected BC-1 and BCBL-1 cells, but not uninfected control cells, Renilla luciferase expression was selectively reduced up to 10-fold. Interestingly, one of the viral miRNAs (miR-K5) exhibited much higher activity in BC-1 cells than in BCBL-1 cells. Sequence analysis of both viral genomes revealed a single nucleotide polymorphism in the miR-K5 precursor stem-loop, which inhibits the expression of mature miR-K5 in BCBL-1 cells. We show that the primary miR-K5 sequence present in BCBL-1 results in diminished processing by Drosha both in vivo and in vitro. This is the first report of a naturally occurring sequence polymorphism in an miRNA precursor that results in reduced processing and therefore lower levels of mature miRNA expression and function.

scholarly journals The Endogenous and Cell Cycle-dependent Phosphorylation of tau Protein in Living Cells: Implications for Alzheimer’s Disease

1998 ◽  
Vol 9 (6) ◽  
pp. 1495-1512 ◽  
Author(s):  
Susanne Illenberger ◽  
Qingyi Zheng-Fischhöfer ◽  
Ute Preuss ◽  
Karsten Stamer ◽  
Karlheinz Baumann ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Cell Cycle ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Chinese Hamster Ovary Cells ◽  
Phosphorylation Site ◽  
Chinese Hamster ◽  
Microtubule Assembly ◽  
Human Neuroblastoma

In Alzheimer’s disease the neuronal microtubule-associated protein tau becomes highly phosphorylated, loses its binding properties, and aggregates into paired helical filaments. There is increasing evidence that the events leading to this hyperphosphorylation are related to mitotic mechanisms. Hence, we have analyzed the physiological phosphorylation of endogenous tau protein in metabolically labeled human neuroblastoma cells and in Chinese hamster ovary cells stably transfected with tau. In nonsynchronized cultures the phosphorylation pattern was remarkably similar in both cell lines, suggesting a similar balance of kinases and phosphatases with respect to tau. Using phosphopeptide mapping and sequencing we identified 17 phosphorylation sites comprising 80–90% of the total phosphate incorporated. Most of these are in SP or TP motifs, except S214 and S262. Since phosphorylation of microtubule-associated proteins increases during mitosis, concomitant with increased microtubule dynamics, we analyzed cells mitotically arrested with nocodazole. This revealed that S214 is a prominent phosphorylation site in metaphase, but not in interphase. Phosphorylation of this residue strongly decreases the tau–microtubule interaction in vitro, suppresses microtubule assembly, and may be a key factor in the observed detachment of tau from microtubules during mitosis. Since S214 is also phosphorylated in Alzheimer’s disease tau, our results support the view that reactivation of the cell cycle machinery is involved in tau hyperphosphorylation.

scholarly journals Frecuencias alélicas para variantes SNP en el gen Nramp1 en bovinos infectados con Brucella abortus o clasificados por resistencia al patógeno

2009 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Fernando Cerquera M. ◽  
Rodrigo Martínez S. ◽  
Rubén Toro O. ◽  
Jaime Tobón C. ◽  
Jaime Gallego G. ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Brucella Abortus ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Natural Resistance ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Allelic Frequencies ◽  
Bos Taurus Indicus

<p>La resistencia natural a la brucelosis en bovinos ha sido asociada a factores genéticos, principalmente a algunos polimorfismos de nucleótido simple ubicados dentro del gen Nramp1. La presente investigación evalúa el efecto de variantes tipo polimorfismos de nucleótido simple presentes en regiones codificantes y en la región 3’UTR del gen Nramp1, en la clasificación de los animales como resistentes o susceptibles; además se determinan los genotipos predominantes en animales naturalmente infectados y comprobados como positivos por la presencia de anticuerpos anti <em>Brucella abortus</em>. Se establecieron las frecuencias genotípicas y alélicas para cinco polimorfismos de nucleótido simple identificados dentro del gen Nramp1 en animales de las razas blanco orejinegro (<em>Bos taurus taurus</em>) y cebú (<em>Bos taurus indicus</em>) y en muestras serológicamente positivas provenientes de animales cruzados (<em>Bos taurus </em>x <em>Bos indicus</em>). La determinación de genotipos se realizó mediante la metodología polimorfismo conformacional de cadena sencilla. Se realizó un ensayo de desafío infeccioso in vitro, para estimar la capacidad de los macrófagos bovinos para controlar la sobrevivencia bacterial, lo que permitió definir los individuos como resistentes o susceptibles. Los resultados sugieren una asociación significativa del SNP4 (<em>p </em>= 0,0506) con la variación para el fenotipo de susceptibilidad, pues se encontró el genotipo homocigoto (BB) en alta frecuencia en animales catalogados como resistentes y el genotipo heterocigoto (AB) en alta frecuencia en animales catalogados como susceptibles y en animales con títulos de anticuerpos anti <em>Brucella abortus</em>.  </p><p> </p><p><strong>Allelic frequencies for SNP variants in the gene Nramp1 in bovine infected with </strong><strong><em>Brucella abortus </em></strong><strong>or classified by resistance to the pathogen</strong>  </p><p>The natural resistance to brucellosis in cattle has been associated to genetic factors mainly to some single nucleotide polymorphism (SNP), located within Nramp1 gen. The current research has studied the effect of nucleotide variants to be found in coding regions and other one located in 3 non translated region of Nramp1 gene, on the animal classification as resistant or susceptible, moreover was identified the main genotypes to be found on the infected animals, confirmed as positives by antibody antibrucella titles. Was established the genotypic and allelic frequencies for five single nucleotide polymorphism in animals from blanco orejinegro (<em>Bos taurus taurus</em>) and zebu breeds (<em>Bos taurus indicus</em>) and serum samples belonging to positive crossbred animals (<em>Bos taurus x Bos indicus</em>). The genotype was defined by the methodology known as “single strand conformational polymorphism”. To estimate the macrophage capacity to control the bacterial survival, an in vitro assay was performed, which allowed define the phenotype as resistant or susceptible. The results suggest a significant association for SNP4 (p = 0.0506) with the phenotypic variation for resistant or susceptibility, because was found the genotype (BB) at higher frequency in susceptible animals and naturally infected animals, than those resistant animals. </p>

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