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Kinds of Codon Terms modified by Codon Selected AbstractsCodon 129 polymorphism and the E200K mutation do not affect the cellular prion protein isoform composition in the cerebrospinal fluid from patients with Creutzfeldt,Jakob diseaseEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2010Matthias Schmitz Abstract The cellular prion protein (PrPc) is a multifunctional, highly conserved and ubiquitously expressed protein. It undergoes a number of modifications during its post-translational processing, resulting in different PrPc glycoforms and truncated PrPc fragments. Limited data are available in humans on the expression and cleavage of PrPc. In this study we investigated the PrPc isoform composition in the cerebrospinal fluid from patients with different human prion diseases. The first group of patients was affected by sporadic Creutzfeldt,Jakob disease exhibiting different PrP codon 129 genotypes. The second group contained patients with a genetic form of Creutzfeldt,Jakob disease (E200K). The third group consisted of patients with fatal familial insomnia and the last group comprised cases with the Gerstmann,Sträussler,Scheinker syndrome. We examined whether the PrP codon 129 polymorphism in sporadic Creutzfeldt,Jakob disease as well as the type of prion disease in human patients has an impact on the glycosylation and processing of PrPc. Immunoblotting analyses using different monoclonal PrPc antibodies directed against various epitopes of PrPc revealed, for all examined groups of patients, a consistent predominance of the glycosylated PrPc isoforms as compared with the unglycosylated form. In addition, the antibody SAF70 recognized a variety of PrPc fragments with sizes of 21, 18, 13 and 12 kDa. Our findings indicate that the polymorphisms at PrP codon 129, the E200K mutation at codon 200 or the examined types of human transmissible spongiform encephalopathies do not exert a measurable effect on the glycosylation and processing of PrPc in human prion diseases. [source] The Pro variant of the p53 codon 72 polymorphism is associated with hepatocellular carcinoma in Moroccan populationHEPATOLOGY RESEARCH, Issue 9 2007Sayeh Ezzikouri Aim:, Codon 72 polymorphism of the p53 gene has been implicated in cancer risk, and it has been suggested that it may have an impact on the clinical outcome of the disease. Our objective was to evaluate the association between p53 polymorphism at codon 72 and hepatocellular carcinoma (HCC) in the Moroccan population. Methods:, Genomic DNA was extracted from peripheral blood cells of 96 patients with HCC and 222 controls without HCC matched for age, gender and ethnicity. Codon 72 polymorphism of p53 was identified by PCR-restriction fragment length polymorphism, confirmed by sequencing. Results:, Patients with HCC had higher frequencies of Pro/Pro (13.5% vs. 6.3%, P < 0.02) than controls and consequently a 2.3-fold increased risk of liver cancer development (odds ratio [OR], 2.304; 95% confidence interval [CI], 1.014,5.234). In addition, we found a significant association between the p53Arg72Pro polymorphism and the female gender in HCC. Men with Pro/Pro genotype had a 1.57-fold increased risk for HCC, whereas the corresponding genotype in women had a 4.4-fold increased risk of HCC (OR, 4.4; 95% CI, 1.18,16.42). No correlation between the polymorphism and HCC risk was found when comparing the hepatitis C virus (HCV)-positive cases to HCV-positive controls. However, HCV-negative subjects and Pro/Pro genotype had a 3.31-fold increased risk for HCC. Conclusion:, These results provide evidence that p53 polymorphism at codon 72 is a modifier of hepatocarcinogenesis, especially in women and HCV-negative subjects. [source] Deceptive hyperbilirubinaemia in a newborn with familial lipoprotein lipase deficiencyJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2001PC Ng Abstract: A rare case of familial lipoprotein lipase (LPL) deficiency in a Chinese newborn who presented with severe hyperbilirubinaemia is described. The falsely high serum bilirubin concentration was subsequently found to be a laboratory analytical error caused by interference of optical measurement of the lipaemic serum. Hypertriglyceridaemia and chylomicronaemia could be safely and effectively controlled by a fat-restricted diet using either modified elementary milk formula fortified with protein, calories and minerals, or the commercially available special milk formula such as Monogen or Portagen. DNA sequence analysis of the patient showed a Leu252Arg mutation in exon 6 of both alleles of the LPL gene. Although the parents were unrelated, both were heterozygous carriers of the same genetic defect. Codon 252 in exon 6 appears to be a common and critical site of mutation in the LPL gene of Chinese, but this important association has not been recognized previously. [source] A Proline-Threonine Substitution in Codon 351 of ADH1C Is Common in Native AmericansALCOHOLISM, Issue 12 2002Michael V. Osier Background The alcohol dehydrogenase (ADH) genes have been repeatedly associated with protection against alcoholism. Until now, only four protein coding variants have been identified (ADH1C Arg271Gln, Ile349Val, ADH1B Arg47His, and Arg369Cys), and only two of these (ADH1C Ile349Val and ADH1B Arg47His) have been routinely tested in association studies with alcoholism. Methods The new ADH1C*351Thr allele was identified by direct sequencing of DNA samples that gave different typing results for the ADH1C Ile349Val polymorphism with different typing protocols. Results A new coding variant has been identified at codon 351 of ADH1C. This allele is found in most Native American populations that we have studied with allele frequencies of the new ADH1C*351Thr allele as high as 26%. Only two instances of this allele have been seen in a large survey of African and Eurasian populations. Conclusions The changes in charge, size, and rotational mobility caused by this amino acid substitution should be significant. Because this new variant codes for a new enzyme form in Native Americans, the kinetics of this enzyme should be studied and considered in studies of the role of ADH1C in the protection against alcoholism in Native Americans. [source] Codon 101 of PRKCG, a preferential mutation site in SCA14MOVEMENT DISORDERS, Issue 12 2007Dagmar Nolte [source] Polymorphism and signature of selection in the MHC class I genes of the three-spined stickleback Gasterosteus aculeatusJOURNAL OF FISH BIOLOGY, Issue 2006H. Schaschl The role and intensity of positive selection maintaining the polymorphism of major histocompatibility complex (MHC) class I genes in the three-spined stickleback Gasterosteus aculeatus was investigated. The highly polymorphic set of MHC class I genes found was organized in a single linkage group. Between 5 and 14 sequence variants per individual were identified by single-stranded conformation polymorphism (SSCP) analysis. Segregation analysis studied in 10 three-spined stickleback families followed the expected pattern of Mendelian inheritance. The gamete fusion in three-spined stickleback thus seems to be random with respect to the MHC class I genes. The DNA sequence analyses showed that the expressed MHC class I loci are under strong selection pressure, possibly mediated by parasites. Codons that were revealed to be under positive selection are potentially important in antigen binding. MHC class I sequences did not form significant supported clusters within a phylogenetic tree. Analogous to MHC class II genes, it was not possible to assign the class I sequences to a specific locus, suggesting that the class I genes may have been generated by recent gene duplication. [source] Identification and Repair of Positive Binding Antibodies Containing Randomly Generated Amber Codons from Synthetic Phage Display LibrariesBIOTECHNOLOGY PROGRESS, Issue 3 2006Warren D. Marcus Phage display technology allows for the rapid isolation and characterization of monoclonal antibodies that have vast potential for therapeutic and diagnostic applications. However, the panning process, which utilizes a host strain that suppresses termination by the amber codon, has an inherent bias toward clones containing randomly generated amber stop codons, complicating identification of positive binding antibodies when the antibody genes are finally expressed in a nonsupressor host. Here, we perform biopanning against a Histone 2A peptide using streptavidin- or anti-biotin-coated beads. After four rounds, a dominant clone is characterized but contains a spurious amber stop codon. A protocol is given that readily corrects the amber codon, allowing for soluble antibody production once the phagemid is transformed into a nonsuppressor bacterial strain. This work also highlights the ability to isolate antibodies against a protein antigen by using only a small peptide (15 amino acids) representing a portion of the antigen. [source] Optimized green fluorescent protein variants provide improved single cell resolution of transgene expression in ascidian embryosDEVELOPMENTAL DYNAMICS, Issue 2 2006Robert W. Zeller Abstract The green fluorescent protein (GFP) is used extensively to monitor gene expression and protein localization in living cells, particularly in developing embryos from a variety of species. Several GFP mutations have been characterized that improve protein expression and alter the emission spectra to produce proteins that emit green, blue, cyan, and yellow wavelengths. DsRed and its variants encode proteins that emit in the orange to red wavelengths. Many of these commercially available fluorescent proteins have been "codon optimized" for maximal levels of expression in mammalian cells. We have generated several fluorescent protein color variants that have been codon optimized for maximal expression in the ascidian Ciona intestinalis. By analyzing quantitative time-lapse recordings of transgenic embryos, we demonstrate that, in general, our Ciona optimized variants are detected and expressed at higher levels than commercially available fluorescent proteins. We show that three of these proteins, expressed simultaneously in different spatial domains within the same transgenic embryo are easily detectable using optimized fluorescent filter sets for epifluorescent microscopy. Coupled with recently developed quantitative imaging techniques, our GFP variants should provide useful reagents for monitoring the simultaneous expression of multiple genes in transgenic ascidian embryos. Developmental Dynamics 235:456,467, 2006. © 2005 Wiley-Liss, Inc. [source] Studies of the Ala/Val98 polymorphism of the hepatocyte nuclear factor-1, gene and the relationship to ,-cell function during an OGTT in glucose-tolerant women with and without previous gestational diabetes mellitusDIABETIC MEDICINE, Issue 12 2004J. Lauenborg Abstract Aims In pregnancies complicated by gestational diabetes mellitus (GDM) an increased demand for insulin is not met due to ,-cell dysfunction. An Ala/Val polymorphism at codon 98 of the hepatocyte nuclear factor-1, (HNF-1,) gene has been associated with decreased serum insulin and C-peptide responses during an oral glucose tolerance test (OGTT) in glucose-tolerant subjects. The aims of the present study were to evaluate the influence of the polymorphism on the serum insulin and C-peptide responses to an OGTT in glucose-tolerant women with and without previous GDM and to investigate if this polymorphism is associated with GDM. Methods The Ala/Val98 polymorphism was measured in 376 women of Danish origin with previous GDM, and in 724 age-matched and 310 middle-aged glucose tolerant women using polymerase chain reaction-restriction fragment length polymorphism. Results The allelic frequency of the Ala/Val98 polymorphism was 0.043 [95% confidence interval (CI) 0.028, 0.057] in women with previous GDM vs. 0.037 (95% CI 0.028, 0.047) in age-matched and 0.039 (95% CI 0.024, 0.054) in middle-age women. Among 117 glucose-tolerant women with previous GDM, 10 carriers of the Ala/Val98 polymorphism had a non-significant 27% and 22% reduction in serum C-peptide and insulin levels, respectively, at 30 min during an OGTT. Seventy-eight control subjects carrying the Ala/Val98 polymorphism had a 10% (P = 0.001) and 16% (P = 0.004) reduction in serum C-peptide and insulin levels, respectively, compared with 956 Ala/Ala control subjects. Conclusions The Ala/Val polymorphism at codon98 of HNF-1, is not associated with GDM in Danish women. However, the codon 98 variant is associated with a significant impairment of serum insulin and C-peptide responses during an OGTT in glucose-tolerant women without previous GDM. [source] The influence of the polymorphism in apolipoprotein B codon 2488 on insulin and lipid levels in a Danish twin populationDIABETIC MEDICINE, Issue 1 2002J. Bentzen Abstract Aims The apolipoprotein B codon 2488 polymorphism has been associated with the metabolism of lipoproteins in subjects with Type 2 diabetes. However, no data are available on the influence of the polymorphism on insulin or glucose metabolism. This study examines the impact of the polymorphism on parameters associated with the insulin resistance syndrome in Danish twins. Methods The effect of the polymorphism on lipid, glucose and insulin measures was studied in 548 same sex twins aged 55,74 years. Results The codon 2488 polymorphism influenced fasting triglyceride levels, as well as insulin, as measured at 120 min in an oral glucose tolerance test. Subjects with the genotype T2488T had 14% higher triglyceride levels (P = 0.02) and 31% higher insulin levels (P = 0.004) than subjects with genotype C2488C. In twins discordant for genotype, the T-allele was associated with higher levels of triglyceride (P = 0.04) and insulin (P = 0.02) and lower levels of HDL-cholesterol (P = 0.04). Conclusion The T-allele of the codon 2488 polymorphism influenced parameters related to the insulin resistance syndrome, i.e. increased levels of insulin, increased levels of triglyceride and decreased levels of HDL. As the polymorphism is silent, these effects must be mediated through linkage to other polymorphisms in apolipoprotein B or other genes on chromosome 2. [source] Frequent multiple c-ki- ras oncogene activation in pancreatic juice from patients with benign pancreatic cystsDIGESTIVE ENDOSCOPY, Issue 2 2001Akihiko Nakaizumi Background: We detected benign pancreatic cysts in more than half of 12 cases of in situ pancreatic cancer. A few investigators, having detected K- ras mutation in pancreatic juice before the clinical diagnosis of pancreatic cancer, have suggested that this mutation might be an early event in pancreatic oncogenesis. Therefore, in the present study, we evaluated whether benign pancreatic cysts are a precancerous condition as reflected by K- ras mutation in pancreatic juice. Methods: Pancreatic juice was collected through endoscopic cannulation of the pancreatic duct. Analysis of the mutations was performed using the polymerase chain reaction,preferential homoduplex formation assay. Results: The frequencies and types of K- ras point mutations and the rate of multiplicity of K- ras mutations in patients with benign pancreatic cyst were the same as those with pancreatic cancer. Conclusions: Multiple K- ras codon 12 mutations in the pancreatic juice of patients with benign pancreatic cysts are present as frequently as those with pancreatic cancer. These results indicate that patients with benign cysts may be at a high-risk for the development of pancreatic cancer. [source] Genetic polymorphisms in glutathione S-transferases T1, M1 and P1 and susceptibility to reflux esophagitisDISEASES OF THE ESOPHAGUS, Issue 6 2006B. Liu SUMMARY., Recent studies indicate that the prevalence of reflux esophagitis (RE) in China is increasing. RE is one of the most common esophageal complications associated with gastroesophageal reflux disease (GERD) and RE-Barrett's esophagus-esophageal adenocarcinoma (EAC) sequence has been considered as an histogenesis model for EAC in Western countries. RE is only present in a subset of patients with GERD, suggesting an altered susceptibility to RE may exist in these GERD individuals. However, the genetic changes related with high susceptibility to RE is largely unknown. The polymorphisms in glutathione S-transferases (GSTs) T1, M1 and P1 have been reported with high susceptibity to esophageal cancer in Chinese people. The present case-control study was thus undertaken to characterize the genetic polymorphisms of GSTs and their correlation with susceptibility to RE. One hundred and nine patients with RE, 97 patients with nonerosive reflux disease (NERD) and 97 normal controls were recruited in this study. All the subjects were from Beijing, China, and received endoscopic examination and questionnaires for RE. Genomic DNA was extracted from the lymphocytes of peripheral blood for each subject. Genotypes of the GSTM1 and GSTT1 genes were analyzed by a multiplex PCR method. A,G polymorphism of codon 104 of the GSTP1 gene was detected using PCR-based restriction fragment length polymorphisms (RFLP). The variant GSTP1 genotypes (*A/*B,*B/*B) was found with a high frequency in the case with RE (40%), and followed by NERD (25%) and normal control (22%). The differences were statistically significant (P < 0.05). The risk for RE increased 2.42-fold [odds ratio (OR); 95% confidence interval (95% CI), 2.42 (1.22,4.80)] in the subjects with variant GSTP1 genotype. The subjects with positive variant GSTP1 genotypes and negative H. pylori infection showed increasing tendency for risk of RE [OR (95% CI), 2.67 (1.06,6.70)]. However, the subjects with GSTT1 and GSTM1 polymorphisms did not show any correlation with high risk for RE or NERD. No significant interactions were identified between the variant GSTs and cigarette smoking, or alcohol drinking and subtype of RE. The present result suggests that GSTP1 genetic polymorphism may be one of the high susceptibility factors involved in the mechanisms of RE. H. pylori infection may play a protective role against RE. [source] Nitric oxide and p53 in cancer-prone chronic inflammation and oxyradical overload disease,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2004Julie E. Goodman Abstract Nitric oxide (NO·), which is generated under chronic inflammatory conditions that predispose individuals to cancer, has paradoxical effects. NO· can activate p53, which can result in anti-carcinogenic effects, or it can be mutagenic and increase cancer risk. We explored the mechanisms by which NO· induced p53 activation in vitro and found that NO· induced p53 accumulation and phosphorylation, particularly at ser-15, via ATM and ATR kinases, which then led to cell cycle arrest at G2/M. We next examined proteins in these pathways in both inflamed and normal human colon tissue. Inducible nitric oxide synthase (iNOS) levels and p53-P-ser15 levels were positively correlated with the degree of inflammation and with each other. Additionally, the p53 targets, HDM-2 and p21 (WAF1), were present in ulcerative colitis (UC) colon, but undetectable in normal colon, consistent with activated p53. We also found higher p53 mutant frequencies of both G:C , A:T transitions at the CpG site of codon 248 and C:G , T:A transitions at codon 247 in lesional colon tissue from UC cases versus nonlesional tissue from these cases or colon tissue from normal adult controls. Consistent with nitrosative stress and the deamination of 5-methylcytosine, p53 mutations were also detected in sporadic colon cancer tissue and were associated with iNOS activity in these tissues. These studies identified a potential mechanistic link between NO· and p53 in UC and sporadic colon cancer. Environ. Mol. Mutagen. 44:3,9, 2004. Published 2004 Wiley-Liss, Inc. [source] Novel SDHD germ-line mutations in pheochromocytoma patientsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2007C. Neumayer Abstract Background,SDHD germ-line mutations predispose to pheochromocytoma (PCC) and paraganglioma (PGL). Material and methods, The incidence and types of SDHD germ-line mutations are determined in 70 patients with apparently sporadic adrenal and extra-adrenal PCC. Results,SDHD sequence variants were identified in the germ line of five patients. Two of three novel mutations were in exon 1 and one in exon 3. One patient had a codon 1 missense mutation (M1K) and a concurrent 3-bp deletion in intron 1. Three of 10 family members had only the exon 1 mutation, whereas one had only the intron 1 mutation. The other exon 1 mutation resulted from a deletion of nucleotides 28,33 with a 12-bp in-frame insertion (c.28_33 del ins TAGGAGGCCCTA). This mutation generated a premature stop codon after codon 9 and was also present in the brother who had a bilateral PCC. The third patient with a carotid body tumour, with an abdominal and a thoracic PGL had a 12-bp deletion in exon 3 (codons 91,94, c.271_282 del). Her father carried the same mutation and had bilateral carotid body tumours. Two further patients, one with six PGL, carried a previously described H50R polymorphism, whose disease-specific relevance is currently unclear. The three patients with bona fide SDHD mutations were younger than those without germ-line mutations. Conclusion,SDHD germ-line mutations are rare in patients with PCC, but their identification is an important prerequisite for the clinical care and appropriate management of affected individuals and their families. [source] Co-inheritance of Hb Hershey [,70(E14) Ala,Gly] and Hb La Pommeraie [,133(H11)Val,Met] in a Sicilian subjectEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2010Antonino Giambona Abstract Objectives:,This report represents the first observation in Sicily of two rare , -globin gene variants, Hb Hershey [,70(E14) Ala,Gly] and Hb La Pommeraie [,133(H11)Val,Met], found in a 35-year-old male patient from Messina, in the north-east of Sicily during population screening for hemoglobinopathies. Methods: The occurrence of the Hb variants was assessed by cation exchange chromatography while complete blood counts were obtained using automatic cell counters. Red cell lysates were analyzed by electrophoresis at alkaline and acid pH. Stability of hemoglobin was checked by the isopropanol precipitation test and by the heat tests while inclusion bodies and reticulocyte count were determined by incubation of blood samples with brilliant cresyl blue. Molecular analysis was performed by DNA sequencing of ,- and , -globin genes. Results: We observed an abnormally high performance liquid chromatography elution with a slight reduction in mean corpuscular volume and mean corpuscular haemoglobin parameters and mutations at codon 70 GCC,GGC (Hb Hershey) and at codon 133 GTG,ATG (Hb La Pommeraie) in , -globin gene. Conclusion: Family analysis of three generations demonstrated the presence of these two mutations in trans. So it was possible to describe the phenotypes of these variants in a heterozygous state and in double heterozygous state. [source] A novel mutation in the last exon of ATRX in a patient with , -thalassemia myelodysplastic syndromeEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2006Daniel B. Costa Abstract:, We describe a patient with acquired alpha-thalassemia myelodysplastic syndrome (ATMDS). A previously healthy 66-year-old man presented with hemoglobin of 9.3 g/dL, mean corpuscular volume 59 fL, and a bone marrow aspirate with increased erythroid precursors and hypolobulated megakaryocytes. Hemoglobin H inclusions were seen in most red cells after 1% brilliant cresyl blue supravital stain of the peripheral blood. At the molecular level, we identified of a novel mutation in the most 3, exon of the ATRX gene (CGA,TGA substitution in codon 2407) resulting in a premature termination codon (p.R2407X). This case provides further evidence for a link between ATRX mutations and ATMDS, and suggests a possible role for the conserved Q-box element in ATRX function. [source] Hb Woodville, a rare , -globin variant, caused by codon 6 mutation of the ,1 geneEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2006Vip Viprakasit Abstract:, Since 1995, the national programme for the prevention and control of severe thalassaemia has been implemented in Thailand. This programme is composed of the population screening in pregnant women and couples by osmotic fragility, HbE screening and the confirmation test using haemoglobin analyses by electrophoresis or chromatography. Thereafter, several hitherto unidentified haemoglobins (Hbs) with structural defects are increasingly described and these variants are now easily studied using DNA technology. In this study, the authors describe the haematology and molecular analyses in a 28-yr-old healthy female who was identified as having an exceptionally ,high HbA2' from haemoglobin analysis. Subsequent analyses demonstrated that observed atypical ,HbA2' was, in fact, a rare innocuous , -globin variant, called Hb Woodville [alpha 2 6(A4); Asp , Tyr]. For the first time, this abnormal Hb species is characterised at the molecular level. [source] Clinical and hematological features of codon 17, A-T mutation of ,-thalassemia in Thai patients,EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2 2001Vichai Laosombat Abstract: Forty-one patients with codon 17, A-T mutation of ,-thalassemia, which is commonly found in Thailand, were studied to determine whether it is possible to predict phenotypic severity from genetic factors. The clinical phenotype of homozygotes for codon 17, A-T and compound heterozygotes for codon 17, A-T and ,+ -thalassemia may be used to predict a severe phenotype with TM. However, the clinical phenotype of compound heterozygotes for codon 17, A-T and ,+ -thalassemia or Hb E were variable and could not be accurately predicted. The association of ,-thalassemia2 and milder disease was and was not evident in patients with codon 17, A-T and Hb E. The association between Hb CS gene or the presence of XmnI- G, polymorphism and a mild clinical phenotype is not apparent, indicating the involvement of other ameliorating determinants or genetic modifications. [source] Comparative genomics of the Mill family: a rapidly evolving MHC class,I gene familyEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2004Yutaka Watanabe Abstract Mill (MHC class,I-like located near the leukocyte receptor complex) is a novel family of class,I genes identified in mice that is most closely related to the human MICA/B family. In the present study, we isolated Mill cDNA from rats and carried out a comparative genomic analysis. Rats have two Mill genes orthologous to mouse Mill1 and Mill2 near the leukocyte receptor complex, with expression patterns similar to those of their mouse counterparts. Interspecies sequence comparison indicates that Mill is one of the most rapidly evolving class,I gene families and that non-synonymous substitutions occur more frequently than synonymous substitutions in its ,,1 domain, implicating the involvement of Mill in immune defenses. Interestingly, the ,,2 domain of rat Mill2 contains a premature stop codon in many inbred strains, indicating that Mill2 is not essential for survival. A computer search of the database identified a horse Mill -like expressed sequence tag, indicating that Mill emerged before the radiation of mammals. Hence, the failure to find Mill in human indicates strongly that it was lost from the human lineage. Our present work provides convincing evidence that Mill is akin to the MICA/B family, yet constitutes a distinctgene family. [source] A novel mutation in the PSEN1 gene (L286P) associated with familial early-onset dementia of Alzheimer type and lobar haematomasEUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2007R. Sánchez-Valle The aim of this study was to describe a novel mutation in exon 8 of the presenilin gene (L286P) associated with early-onset autosomal dominant Alzheimer's disease (AD) and lobar haematomas. The proband was a woman who developed cognitive decline with predominant memory loss at the age of 35 years. The patient died at the age of 54 years and the neuropathological examination confirmed the diagnosis of AD. Three of her four siblings, one parent and one sibling of her parent had suffered from cognitive decline at ages between 35 and 42 years. Three of them also presented lobar haematomas. The neuropathological examination, available in one of them, disclosed the presence of severe amyloid angiopathy as the cause of the haematoma. The study of PSEN1 gene with single strand conformation polymorphism technique failed to show abnormalities suggestive of mutations. Direct sequencing disclosed the presence of a missense mutation in codon 286 (L286P) in the proband and her already affected descendent, which was absent in the healthy sibling. L286P is a novel mutation in PSEN1 that causes familial early-onset AD and brain haematomas related to amyloid angiopathy. [source] Creutzfeldt,Jakob disease risk and PRNP codon 129 polymorphism: necessity to revalue current dataEUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2005E. Mitrová The polymorphism at codon 129 (M129V) of the prion protein gene (PRNP) is a recognized genetic marker for susceptibility to Creutzfeldt,Jakob disease (CJD) in the Caucasians. The distribution of this polymorphism in healthy individuals provides an important starting point for the evaluation of CJD risk in the general population. Early studies of reference population cohorts demonstrated that methionine/valine heterozygosity was the most frequent genotype. These studies were performed in relatively small numbers of control subjects and do not correspond with the findings of more recent investigations. In this study, we present an analysis of the codon M129V distribution in 613 corneal donors, representing one of the largest control groups examined to date. Methionine homozygotes represented 48.1%, valine homozygotes 8.7% and methionine/valine heterozygotes 43.2%. While age-related difference was not significant, differentiation according to the gender showed significant difference. The observed highest proportion of methionine homozygotes and statistically significant difference between genders as well as comparison with results obtained in other countries underline the need to re-evaluate the generally used reference data on M129V, including consideration of the gender, age and geographical distribution. [source] Clinical and genetic features of human prion diseases in Catalonia: 1993,2002EUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2004R. Sanchez-Valle We describe the clinical and genetic characteristics of the 85 definite or probable human prion diseases cases died between January 1993 and December 2002 in Catalonia (an autonomous community of Spain, 6 million population). Seventy-three (86%) cases were sporadic Creutzfeld-Jakob diseases (sCJD) (49 definite, 24 probable), with a median age at onset of 66 years. The clinical presentation was dementia in 29 cases, ataxia in 14 and visual symptoms in five. The median survival was 3 months. The 14-3-3 assay was positive in 93% cases, 62% presented periodic sharp wave complexes (PSWC) in EEG but only 18% the typical signs on MRI. Forty-eight sCJD were studied for codon 129 PRNP polymorphism: 69% were methionine/methionine (M/M), 14.5% valine/valine (V/V) and 16.5% M/V. Six out of seven V/V cases did not present PSWC and in two survival was longer than 20 months. Eleven cases (13%) were genetic: five familial fatal insomnia and six familial CJD (fCJD). Up to four (67%) fCJD lacked family history of disease, two presented seizures early at onset and one neurosensorial deafness. The only iatrogenic case was related to a dura mater graft. No case of variant CJD was registered. The study confirms in our population the consistent pattern reported worldwide on human prion diseases. Atypical features were seen more frequently in sporadic 129 V/V CJD and fCJD cases. [source] Codon 129 polymorphism and the E200K mutation do not affect the cellular prion protein isoform composition in the cerebrospinal fluid from patients with Creutzfeldt,Jakob diseaseEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2010Matthias Schmitz Abstract The cellular prion protein (PrPc) is a multifunctional, highly conserved and ubiquitously expressed protein. It undergoes a number of modifications during its post-translational processing, resulting in different PrPc glycoforms and truncated PrPc fragments. Limited data are available in humans on the expression and cleavage of PrPc. In this study we investigated the PrPc isoform composition in the cerebrospinal fluid from patients with different human prion diseases. The first group of patients was affected by sporadic Creutzfeldt,Jakob disease exhibiting different PrP codon 129 genotypes. The second group contained patients with a genetic form of Creutzfeldt,Jakob disease (E200K). The third group consisted of patients with fatal familial insomnia and the last group comprised cases with the Gerstmann,Sträussler,Scheinker syndrome. We examined whether the PrP codon 129 polymorphism in sporadic Creutzfeldt,Jakob disease as well as the type of prion disease in human patients has an impact on the glycosylation and processing of PrPc. Immunoblotting analyses using different monoclonal PrPc antibodies directed against various epitopes of PrPc revealed, for all examined groups of patients, a consistent predominance of the glycosylated PrPc isoforms as compared with the unglycosylated form. In addition, the antibody SAF70 recognized a variety of PrPc fragments with sizes of 21, 18, 13 and 12 kDa. Our findings indicate that the polymorphisms at PrP codon 129, the E200K mutation at codon 200 or the examined types of human transmissible spongiform encephalopathies do not exert a measurable effect on the glycosylation and processing of PrPc in human prion diseases. [source] Characterization of porcine dentin sialoprotein (DSP) and dentin sialophosphoprotein (DSPP) cDNA clonesEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2003Yasuo Yamakoshi Dentin sialophosphoprotein (DSPP) is a chimeric glycoprotein with dentin sialoprotein (DSP) on its N -terminus and dentin phosphoprotein (DPP) on its C -terminus. We have constructed and screened a unidirectional cDNA library derived from the pulp organ of developing pig teeth, and isolated cDNA clones encoding DSP-only, as well as two DSPP clones with alternative sequences in their 3, coding regions. The DSP-only transcript has an open reading frame of 386 codons, and is generated through the use of a polyadenylation signal within intron 4, immediately following the DSP coding region. the use of this polyadenylation signal deletes the DPP coding region and places a TGA translation termination signal as the fourth codon following the exon 4-encoded segment. The DSPP cDNAs contain open reading frames of 593 and 600 codons. Northern blots hybridized to radiolabeled DSP probes showed bands at 1.4, 2.5, 4.4, and 4.8 kb. Cloning and characterization of reverse transcriptase polymerase chain reaction products confirmed the existence of mRNA encoding pDSP386, pDSPP593, and pDSPP600in vivo, but also suggested that DNA sequence redundancies in the DSPP coding region make it prone to cloning artifacts. [source] Hot spot mutations in keratin 2e suggest a correlation between genotype and phenotype in patients with ichthyosis bullosa of SiemensEXPERIMENTAL DERMATOLOGY, Issue 1 2000Y. Suga Abstract: Ichthyosis bullosa of Siemens (IBS) is a rare disorder of cornification characterized by blister formation in the upper suprabasal layers of the epidermis. Molecular analysis of IBS has identified mutations in the keratin 2e (K2e) gene, which is located in the type II keratin gene cluster on chromosome 12q. We have studied two IBS families and have identified heterozygous point mutations in codon 493 of the K2e gene in both families. Whereas a non-conservative amino acid substitution at position 117 of the 2B region of K2e (E117K) was associated with a severe phenotype in family 1, family 2 showed mild clinical features as a result of a conservative substitution (E117D). These data suggest a phenotype,genotype correlation in these families. [source] Identification of a novel mutation in keratin 1 in a family with epidermolytic hyperkeratosisEXPERIMENTAL DERMATOLOGY, Issue 1 2000M. J. Arin Abstract: Epidermolytic hyperkeratosis (EHK) is a hereditary skin disorder typified by blistering due to cytolysis. One in 100,000 individuals is affected by this autosomal-dominant disease. The onset of the disease phenotype is typically at birth. Histological and ultrastructural examination of the epidermis shows a thickened stratum corneum and tonofilament clumping around the nucleus of suprabasal keratinocytes. Linkage studies localized the disease genes on chromosomes 12q and 17q which contain the type II and type I keratin gene clusters. Recently, several point mutations in the genes encoding the suprabasal keratins, K1 and K10, have been reported in EHK patients. We have investigated a large kindred affected by EHK and identified a new point mutation in the 2B region of keratin 1 (I107T), resulting from a T to C transition in codon 478. [source] Characterization of sequence variations in human histone H1.2 and H1.4 subtypesFEBS JOURNAL, Issue 14 2005Bettina Sarg In humans, eight types of histone H1 exist (H1.1,H1.5, H1°, H1t and H1oo), all consisting of a highly conserved globular domain and less conserved N- and C-terminal tails. Although the precise functions of these isoforms are not yet understood, and H1 subtypes have been found to be dispensable for mammalian development, it is now clear that specific functions may be assigned to certain individual H1 subtypes. Moreover, microsequence variations within the isoforms, such as polymorphisms or mutations, may have biological significance because of the high degree of sequence conservation of these proteins. This study used a hydrophilic interaction liquid chromatographic method to detect sequence variants within the subtypes. Two deviations from wild-type H1 sequences were found. In K562 erythroleukemic cells, alanine at position 17 in H1.2 was replaced by valine, and, in Raji B lymphoblastoid cells, lysine at position 173 in H1.4 was replaced by arginine. We confirmed these findings by DNA sequencing of the corresponding gene segments. In K562 cells, a homozygous GCC,GTC shift was found at codon 18, giving rise to H1.2 Ala17Val because the initial methionine is removed in H1 histones. Raji cells showed a heterozygous AAA,AGA codon change at position 174 in H1.4, corresponding to the Lys173Arg substitution. The allele frequency of these sequence variants in a normal Swedish population was found to be 6.8% for the H1.2 GCC,GTC shift, indicating that this is a relatively frequent polymorphism. The AAA,AGA codon change in H1.4 was detected only in Raji cells and was not present in a normal population or in six other cell lines derived from individuals suffering from Burkitt's lymphoma. The significance of these sequence variants is unclear, but increasing evidence indicates that minor sequence variations in linker histones may change their binding characteristics, influence chromatin remodeling, and specifically affect important cellular functions. [source] Identification of alternative promoter usage for the matrix Gla protein geneFEBS JOURNAL, Issue 6 2005Evidence for differential expression during early development in Xenopus laevis Recent cloning of the Xenopus laevis (Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5,-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon. DNA sequence analysis identified a second TATA-like DNA motif located at the 3, end of intron 1 and adjacent to the ATG-containing second exon. This putative proximal promoter was found to direct transcription of the luciferase reporter gene in the X. laevis A6 cell line, a result confirmed by subsequent deletion mutant analysis. RT-PCR analysis of XlMGP gene expression during early development identified a different temporal expression of the two transcripts, strongly suggesting differential promoter activation under the control of either maternally inherited or developmentally induced regulatory factors. Our results provide further evidence of the usefulness of nonmammalian model systems to elucidate the complex regulation of MGP gene transcription and raise the possibility that a similar mechanism of regulation may also exist in mammals. [source] Kinetic study of sn -glycerol-1-phosphate dehydrogenase from the aerobic hyperthermophilic archaeon, Aeropyrum pernix K1FEBS JOURNAL, Issue 3 2002Jin-Suk Han A gene having high sequence homology (45,49%) with the glycerol-1-phosphate dehydrogenase gene from Methanobacterium thermoautotrophicum was cloned from the aerobic hyperthermophilic archaeon Aeropyrum pernix K1 (JCM 9820). This gene expressed in Escherichia coli with the pET vector system consists of 1113 nucleotides with an ATG initiation codon and a TAG termination codon. The molecular mass of the purified enzyme was estimated to be 38 kDa by SDS/PAGE and 72.4 kDa by gel column chromatography, indicating presence as a dimer. The optimum reaction temperature of this enzyme was observed to be 94,96 °C at near neutral pH. This enzyme was subjected to two-substrate kinetic analysis. The enzyme showed substrate specificity for NAD(P)H- dependent dihydroxyacetone phosphate reduction and NAD+ -dependent,glycerol-1-phosphate (Gro1P) oxidation. NADP+ -dependent Gro1P oxidation was not observed with this enzyme. For the production of Gro1P in A. pernix cells, NADPH is the preferred coenzyme rather than NADH. Gro1P acted as a noncompetitive inhibitor against dihydroxyacetone phosphate and NAD(P)H. However, NAD(P)+ acted as a competitive inhibitor against NAD(P)H and as a noncompetitive inhibitor against dihydroxyacetone phosphate. This kinetic data indicates that the catalytic reaction by glycerol- 1-phosphate dehydrogenase from A. pernix follows a ordered bi,bi mechanism. [source] The polypeptide chain release factor eRF1 specifically contacts the s4UGA stop codon located in the A site of eukaryotic ribosomesFEBS JOURNAL, Issue 10 2001Laurent Chavatte It has been shown previously [Brown, C.M. & Tate, W.P. (1994) J. Biol. Chem.269, 33164,33170.] that the polypeptide chain release factor RF2 involved in translation termination in prokaryotes was able to photocrossreact with mini-messenger RNAs containing stop signals in which U was replaced by 4-thiouridine (s4U). Here, using the same strategy we have monitored photocrosslinking to eukaryotic ribosomal components of 14-mer mRNA in the presence of , and 42-mer mRNA in the presence of tRNAAsp (tRNAAsp gene transcript). We show that: (a) both 14-mer and 42-mer mRNAs crossreact with ribosomal RNA and ribosomal proteins. The patterns of the crosslinked ribosomal proteins are similar with both mRNAs and sensitive to ionic conditions; (b) the crosslinking patterns obtained with 42-mer mRNAs show characteristic modification upon addition of tRNAAsp providing evidence for appropriate mRNA phasing onto the ribosome. Similar changes are not detected with the 14-mer pairs; (c) when eukaryotic polypeptide chain release factor 1 (eRF1) is added to the ribosome·tRNAAsp complex it crossreacts with the 42-mer mRNA containing the s4UGA stop codon located in the A site, but not with the s4UCA sense codon; this crosslink involves the N-terminal and middle domains of eRF1 but not the C domain which interacts with eukaryotic polypeptide chain release factor 3 (eRF3); (d) addition of eRF3 has no effect on the yield of eRF1,42-mer mRNA crosslinking and eRF3 does not crossreact with 42-mer mRNA. These experiments delineate the in vitro conditions allowing optimal phasing of mRNA on the eukaryotic ribosome and demonstrate a direct and specific contact of ,core' eRF1 and s4UGA stop codon within the ribosomal A site. [source] | ||||||||||||||||||||||||||||||||||||||||