scholarly journals Contribution of the 15 amino acid repeats of truncated APC to β-catenin degradation and selection of APC mutations in colorectal tumours from FAP patients

Oncogene ◽  
2009 ◽  
Vol 29 (11) ◽  
pp. 1663-1671 ◽  
Author(s):  
E M Kohler ◽  
K Brauburger ◽  
J Behrens ◽  
J Schneikert
Keyword(s):  
Amino Acid ◽  
Amino Acid Repeats ◽  
Apc Mutations ◽  
Colorectal Tumours ◽  
Selection Of

Bioluminescent proteins prediction with voting strategy.

2020 ◽  
Vol 15 ◽  
Author(s):  
Shulin Zhao ◽  
Ying Ju ◽  
Xiucai Ye ◽  
Jun Zhang ◽  
Shuguang Han
Keyword(s):  
Amino Acid ◽  
Model Building ◽  
Prediction Method ◽  
Pair Composition ◽  
Proposed Model ◽  
Counting Rules ◽  
Significant Phenomenon ◽  
Voting Strategy ◽  
Improved Accuracy ◽  
Selection Of

Background: Bioluminescence is a unique and significant phenomenon in nature. Bioluminescence is important for the lifecycle of some organisms and is valuable in biomedical research, including for gene expression analysis and bioluminescence imaging technology.In recent years, researchers have identified a number of methods for predicting bioluminescent proteins (BLPs), which have increased in accuracy, but could be further improved. Method: In this paper, we propose a new bioluminescent proteins prediction method based on a voting algorithm. We used four methods of feature extraction based on the amino acid sequence. We extracted 314 dimensional features in total from amino acid composition, physicochemical properties and k-spacer amino acid pair composition. In order to obtain the highest MCC value to establish the optimal prediction model, then used a voting algorithm to build the model.To create the best performing model, we discuss the selection of base classifiers and vote counting rules. Results: Our proposed model achieved 93.4% accuracy, 93.4% sensitivity and 91.7% specificity in the test set, which was better than any other method. We also improved a previous prediction of bioluminescent proteins in three lineages using our model building method, resulting in greatly improved accuracy.

scholarly journals Amino Acid Repeats Cause Extraordinary Coding Sequence Variation in the Social Amoeba Dictyostelium discoideum

PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e46150 ◽  
Author(s):  
Clea Scala ◽  
Xiangjun Tian ◽  
Natasha J. Mehdiabadi ◽  
Margaret H. Smith ◽  
Gerda Saxer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dictyostelium Discoideum ◽  
Sequence Variation ◽  
Social Amoeba ◽  
Coding Sequence ◽  
Amino Acid Repeats ◽  
The Social

scholarly journals Characterization of Resistance to the Nonnucleoside NS5B Inhibitor Filibuvir in Hepatitis C Virus-Infected Patients

2011 ◽  
Vol 56 (3) ◽  
pp. 1331-1341 ◽  
Author(s):  
Philip J. F. Troke ◽  
Marilyn Lewis ◽  
Paul Simpson ◽  
Katrina Gore ◽  
Jennifer Hammond ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Site Directed Mutagenesis ◽  
Phenotypic Resistance ◽  
Number Of Patients ◽  
Chronic Hcv ◽  
Selection Of

ABSTRACTFilibuvir (PF-00868554) is an investigational nonnucleoside inhibitor of the hepatitis C virus (HCV) nonstructural 5B (NS5B) RNA-dependent RNA polymerase currently in development for treating chronic HCV infection. The aim of this study was to characterize the selection of filibuvir-resistant variants in HCV-infected individuals receiving filibuvir as short (3- to 10-day) monotherapy. We identified amino acid M423 as the primary site of mutation arising upon filibuvir dosing. Through bulk cloning of clinical NS5B sequences into a transient-replicon system, and supported by site-directed mutagenesis of the Con1 replicon, we confirmed that mutations M423I/T/V mediate phenotypic resistance. Selection in patients of an NS5B mutation at M423 was associated with a reduced replicative capacityin vitrorelative to the pretherapy sequence; consistent with this, reversion to wild-type M423 was observed in the majority of patients following therapy cessation. Mutations at NS5B residues R422 and M426 were detected in a small number of patients at baseline or the end of therapy and also mediate reductions in filibuvir susceptibility, suggesting these are rare but clinically relevant alternative resistance pathways. Amino acid variants at position M423 in HCV NS5B polymerase are the preferred pathway for selection of viral resistance to filibuvirin vivo.

scholarly journals Potential Selection of LMP1 Variants in Nasopharyngeal Carcinoma

2004 ◽  
Vol 78 (2) ◽  
pp. 868-881 ◽  
Author(s):  
Rachel H. Edwards ◽  
Diane Sitki-Green ◽  
Dominic T. Moore ◽  
Nancy Raab-Traub
Keyword(s):  
Amino Acid ◽  
Cytotoxic T Lymphocyte ◽  
Amino Acid Sequences ◽  
Barr Virus ◽  
Distinct Sequence ◽  
Epstein Barr ◽  
Virus Latent Membrane Protein ◽  
Multiple Strains ◽  
Carboxy Terminal ◽  
Selection Of

ABSTRACT Seven distinct sequence variants of the Epstein-Barr virus latent membrane protein 1 (LMP1) have been identified by distinguishing amino acid changes in the carboxy-terminal domain. In this study the transmembrane domains are shown to segregate identically with the distinct carboxy-terminal amino acid sequences. Since strains of LMP1 have been shown to differ in abundance between blood and throat washes, nasopharyngeal carcinomas (NPCs) from areas of endemicity and nonendemicity with matching blood were analyzed by using a heteroduplex tracking assay to distinguish LMP1 variants. Striking differences were found between the compartments with the Ch1 strain prevalent in the NPCs from areas of endemicity and nonendemicity and the B958 strain prevalent in the blood of the endemic samples, whereas multiple strains of LMP1 were prevalent in the blood of the nonendemic samples. The possible selection against the B958 strain appearing in the tumor was highly significant (P < 0.0001). Sequence analysis of the full-length LMP1 variants revealed changes in many of the known and computer-predicted HLA-restricted epitopes with changes in key positions in multiple, potential epitopes for the specific HLA of the patients. These amino acid substitutions at key positions in the LMP1 epitopes may result in a reduced cytotoxic-T-lymphocyte response. These data indicate that strains with specific variants of LMP1 are more likely to be found in NPC. The predominance of specific LMP1 variants in NPC could reflect differences in the biologic or molecular properties of the distinct forms of LMP1 or possible immune selection.

Directed selection of amino acid changes in the influenza hemagglutinin and neuraminidase affecting protein antigenicity

Vaccine ◽  
2018 ◽  
Vol 36 (43) ◽  
pp. 6383-6392 ◽  
Author(s):  
Marta L. DeDiego ◽  
Kevin Chiem ◽  
David J. Topham
Keyword(s):  
Amino Acid ◽  
Influenza Hemagglutinin ◽  
Selection Of

Tandem Amino Acid Repeats From Trypanosoma cruzi Shed Antigens Increase the Half-Life of Proteins in Blood

Blood ◽  
1999 ◽  
Vol 93 (6) ◽  
pp. 2025-2032 ◽  
Author(s):  
Carlos A. Buscaglia ◽  
Julieta Alfonso ◽  
Oscar Campetella ◽  
Alberto C.C. Frasch
Keyword(s):  
Amino Acid ◽  
Trypanosoma Cruzi ◽  
Half Life ◽  
Tandem Repeats ◽  
Sialidase Activity ◽  
Chimeric Enzymes ◽  
Amino Acid Repeats ◽  
Functional Aspects ◽  
Glutathione S Transferases

Proteins containing amino acid repeats are widespread among protozoan parasites. It has been suggested that these repetitive structures act as immunomodulators, but other functional aspects may be of primary importance. We have recently suggested that tandem repeats present in Trypanosoma cruzi trans-sialidase stabilize the catalytic activity in blood. Because the parasite releasestrans-sialidase, this delayed clearance of the enzyme might have implications in vivo. In the present work, the ability of repetitive units from different T. cruzi molecules in stabilizing trans-sialidase activity in blood was evaluated. It is shown that repeats present on T. cruzi shed proteins (antigens 13 and Shed-Acute-Phase-Antigen [SAPA]) increase trans-sialidase half-life in blood from 7 to almost 35 hours. Conversely, those repeats present in intracellular T. cruzi proteins only increase the enzyme half-life in blood up to 15 hours. Despite these results, comparative analysis of structural and catalytic properties of both groups of chimeric enzymes show no substantial differences. Interestingly, antigens 13 and SAPA also increase the persistence in blood of chimeric glutathione S-transferases, thus suggesting that this effect is inherent to these repeats and independent of the carrier protein. Although the molecular basis of this phenomenon is still uncertain, its biotechnological potential can be envisaged.

scholarly journals Satellites in the prokaryote world

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Juan A. Subirana ◽  
Xavier Messeguer
Keyword(s):  
Amino Acid ◽  
Tandem Repeats ◽  
Reference Group ◽  
Evolutionary Relationship ◽  
Short Length ◽  
Evolutionary Significance ◽  
Leptospira Interrogans ◽  
Amino Acid Repeats ◽  
Representative Species ◽  
Eukaryotic Genomes

Abstract Background Satellites or tandem repeats are very abundant in many eukaryotic genomes. Occasionally they have been reported to be present in some prokaryotes, but to our knowledge there is no general comparative study on their occurrence. For this reason we present here an overview of the distribution and properties of satellites in a set of representative species. Our results provide novel insights into the evolutionary relationship between eukaryotes, Archaea and Bacteria. Results We have searched all possible satellites present in the NCBI reference group of genomes in Archaea (142 species) and in Bacteria (119 species), detecting 2735 satellites in Archaea and 1067 in Bacteria. We have found that the distribution of satellites is very variable in different organisms. The archaeal Methanosarcina class stands out for the large amount of satellites in their genomes. Satellites from a few species have similar characteristics to those in eukaryotes, but most species have very few satellites: only 21 species in Archaea and 18 in Bacteria have more than 4 satellites/Mb. The distribution of satellites in these species is reminiscent of what is found in eukaryotes, but we find two significant differences: most satellites have a short length and many of them correspond to segments of genes coding for amino acid repeats. Transposition of non-coding satellites throughout the genome occurs rarely: only in the bacteria Leptospira interrogans and the archaea Methanocella conradii we have detected satellite families of transposed satellites with long repeats. Conclusions Our results demonstrate that the presence of satellites in the genome is not an exclusive feature of eukaryotes. We have described a few prokaryotes which do contain satellites. We present a discussion on their eventual evolutionary significance.

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