ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    FALCON@home: a high-throughput protein structure prediction server based on remote homologue recognition (2016)
    Oxford University Press
    Details
    Publication Date: 2016-02-02
    Description: : The protein structure prediction approaches can be categorized into template-based modeling (including homology modeling and threading) and free modeling. However, the existing threading tools perform poorly on remote homologous proteins. Thus, improving fold recognition for remote homologous proteins remains a challenge. Besides, the proteome-wide structure prediction poses another challenge of increasing prediction throughput. In this study, we presented FALCON@home as a protein structure prediction server focusing on remote homologue identification. The design of FALCON@home is based on the observation that a structural template, especially for remote homologous proteins, consists of conserved regions interweaved with highly variable regions. The highly variable regions lead to vague alignments in threading approaches. Thus, FALCON@home first extracts conserved regions from each template and then aligns a query protein with conserved regions only rather than the full-length template directly. This helps avoid the vague alignments rooted in highly variable regions, improving remote homologue identification. We implemented FALCON@home using the Berkeley Open Infrastructure of Network Computing (BOINC) volunteer computing protocol. With computation power donated from over 20 000 volunteer CPUs, FALCON@home shows a throughput as high as processing of over 1000 proteins per day. In the Critical Assessment of protein Structure Prediction (CASP11), the FALCON@home-based prediction was ranked the 12th in the template-based modeling category. As an application, the structures of 880 mouse mitochondria proteins were predicted, which revealed the significant correlation between protein half-lives and protein structural factors. Availability and implementation: FALCON@home is freely available at http://protein.ict.ac.cn/FALCON/ . Contact: shuaicli@cityu.edu.hk , dbu@ict.ac.cn Supplementary information: Supplementary data are available at Bioinformatics online.
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
    Topics: Biology , Computer Science , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Multiple alignment-free sequence comparison (2013)
    Oxford University Press
    Details
    Publication Date: 2013-10-19
    Description: Motivation: Recently, a range of new statistics have become available for the alignment-free comparison of two sequences based on k -tuple word content. Here, we extend these statistics to the simultaneous comparison of more than two sequences. Our suite of statistics contains, first, and , extensions of statistics for pairwise comparison of the joint k -tuple content of all the sequences, and second, , and , averages of sums of pairwise comparison statistics. The two tasks we consider are, first, to identify sequences that are similar to a set of target sequences, and, second, to measure the similarity within a set of sequences. Results: Our investigation uses both simulated data as well as cis -regulatory module data where the task is to identify cis -regulatory modules with similar transcription factor binding sites. We find that although for real data, all of our statistics show a similar performance, on simulated data the Shepp-type statistics are in some instances outperformed by star-type statistics. The multiple alignment-free statistics are more sensitive to contamination in the data than the pairwise average statistics. Availability: Our implementation of the five statistics is available as R package named ‘multiAlignFree’ at be http://www-rcf.usc.edu/~fsun/Programs/multiAlignFree/multiAlignFreemain.html . Contact: reinert@stats.ox.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
    Topics: Biology , Computer Science , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Genetic factors affecting gene transcription and catalytic activity of UDP-glucuronosyltransferases in human liver (2014)
    Oxford University Press
    Details
    Publication Date: 2014-09-20
    Description: The aim of this study was to discover cis - and trans -acting factors significantly affecting mRNA expression and catalytic activity of human hepatic UDP-glucuronosyltransferases (UGTs). Transcription levels of five major hepatic UGT1A ( UGT1A1, UGT1A3, UGT1A4, UGT1A6 and UGT1A9 ) and five UGT2B ( UGT2B4, UGT2B7, UGT2B10, UGT2B15 and UGT2B17 ) genes were quantified in human liver tissue samples ( n = 125) using real-time PCR. Glucuronidation activities of 14 substrates were measured in 47 livers. We genotyped 167 tagSNPs (single-nucleotide polymorphisms) in UGT1A ( n = 43) and UGT2B ( n = 124), as well as the known functional UGT1A1*28 and UGT2B17 CNV (copy number variation) polymorphisms. Transcription levels of 15 transcription factors (TFs) known to regulate these UGTs were quantified. We found that UGT expression and activity were highly variable among the livers (median and range of coefficient of variations: 135%, 74–217% and 52%, 39–105%, respectively). CAR, PXR and ESR1 were found to be the most important trans -regulators of UGT transcription (median and range of correlation coefficients: 46%, 6–58%; 47%, 9–58%; and 52%, 24–75%, respectively). Hepatic UGT activities were mainly determined by UGT gene transcription levels. Twenty-one polymorphisms were significantly (FDR-adjusted P 〈 0.05) associated with mRNA expression and/or activities of UGT1A1 , UGT1A3 and UGT2B17 . We found novel SNPs in the UGT2B17 CNV region accounting for variability in UGT2B17 gene transcription and testosterone glucuronidation rate, in addition to that attributable to the UGT2B17 CNV. Our study discovered novel pharmacogenetic markers and provided detailed insight into the genetic network regulating hepatic UGTs.
    Print ISSN: 0964-6906
    Electronic ISSN: 1460-2083
    Topics: Biology , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Multiple pathogenic proteins implicated in neuronopathic Gaucher disease mice (2014)
    Oxford University Press
    Details
    Publication Date: 2014-07-05
    Description: Gaucher disease, a prevalent lysosomal storage disease (LSD), is caused by insufficient activity of acid β-glucosidase (GCase) and the resultant glucosylceramide (GC)/glucosylsphingosine (GS) accumulation in visceral organs (Type 1) and the central nervous system (Types 2 and 3). Recent clinical and genetic studies implicate a pathogenic link between Gaucher and neurodegenerative diseases. The aggregation and inclusion bodies of α-synuclein with ubiquitin are present in the brains of Gaucher disease patients and mouse models. Indirect evidence of β-amyloid pathology promoting α-synuclein fibrillation supports these pathogenic proteins as a common feature in neurodegenerative diseases. Here, multiple proteins are implicated in the pathogenesis of chronic neuronopathic Gaucher disease (nGD). Immunohistochemical and biochemical analyses showed significant amounts of β-amyloid and amyloid precursor protein (APP) aggregates in the cortex, hippocampus, stratum and substantia nigra of the nGD mice. APP aggregates were in neuronal cells and colocalized with α-synuclein signals. A majority of APP co-localized with the mitochondrial markers TOM40 and Cox IV; a small portion co-localized with the autophagy proteins, P62/LC3, and the lysosomal marker, LAMP1. In cultured wild-type brain cortical neural cells, the GCase-irreversible inhibitor, conduritol B epoxide (CBE), reproduced the APP/α-synuclein aggregation and the accumulation of GC/GS. Ultrastructural studies showed numerous larger-sized and electron-dense mitochondria in nGD cerebral cortical neural cells. Significant reductions of mitochondrial adenosine triphosphate production and oxygen consumption (28–40%) were detected in nGD brains and in CBE-treated neural cells. These studies implicate defective GCase function and GC/GS accumulation as risk factors for mitochondrial dysfunction and the multi-proteinopathies (α-synuclein-, APP- and Aβ-aggregates) in nGD.
    Print ISSN: 0964-6906
    Electronic ISSN: 1460-2083
    Topics: Biology , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    POLG2 disease variants: analyses reveal a dominant negative heterodimer, altered mitochondrial localization and impaired respiratory capacity (2015)
    Oxford University Press
    Details
    Publication Date: 2015-08-27
    Description: Human mitochondrial DNA (mtDNA) is replicated and repaired by the mtDNA polymerase gamma, pol. Pol is composed of three subunits encoded by two nuclear genes: (1) POLG codes for the 140-kilodalton (kDa) catalytic subunit, p140 and (2) POLG2 encodes the ~110-kDa homodimeric accessory subunit, p55. Specific mutations are associated with POLG - or POLG2 -related disorders. During DNA replication the p55 accessory subunit binds to p140 and increases processivity by preventing pol's dissociation from the template. To date, studies have demonstrated that homodimeric p55 disease variants are deficient in the ability to stimulate p140; however, all patients currently identified with POLG2 -related disorders are heterozygotes. In these patients, we expect p55 to occur as 25% wild-type (WT) homodimers, 25% variant homodimers and 50% heterodimers. We report the development of a tandem affinity strategy to isolate p55 heterodimers. The WT/G451E p55 heterodimer impairs pol function in vitro , demonstrating that the POLG2 c.1352G〉A/p.G451E mutation encodes a dominant negative protein. To analyze the subcellular consequence of disease mutations in HEK293 cells, we designed plasmids encoding p55 disease variants tagged with green fluorescent protein (GFP). P205R and L475DfsX2 p55 variants exhibit irregular diffuse mitochondrial fluorescence and unlike WT p55, they fail to form distinct puncta associated with mtDNA nucleoids. Furthermore, homogenous preparations of P205R and L475DfsX2 p55 form aberrant reducible multimers. We predict that abnormal protein folding or aggregation or both contribute to the pathophysiology of these disorders. Examination of mitochondrial bioenergetics in stable cell lines overexpressing GFP-tagged p55 variants revealed impaired mitochondrial reserve capacity.
    Print ISSN: 0964-6906
    Electronic ISSN: 1460-2083
    Topics: Biology , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Graphlet-based measures are suitable for biological network comparison (2013)
    Oxford University Press
    Details
    Publication Date: 2013-02-13
    Description: Motivation : Large amounts of biological network data exist for many species. Analogous to sequence comparison, network comparison aims to provide biological insight. Graphlet-based methods are proving to be useful in this respect. Recently some doubt has arisen concerning the applicability of graphlet-based measures to low edge density networks—in particular that the methods are ‘unstable’—and further that no existing network model matches the structure found in real biological networks. Results : We demonstrate that it is the model networks themselves that are ‘unstable’ at low edge density and that graphlet-based measures correctly reflect this instability. Furthermore, while model network topology is unstable at low edge density, biological network topology is stable. In particular, one must distinguish between average density and local density. While model networks of low average edge densities also have low local edge density, that is not the case with protein–protein interaction (PPI) networks: real PPI networks have low average edge density, but high local edge densities, and hence, they (and thus graphlet-based measures) are stable on these networks. Finally, we use a recently devised non-parametric statistical test to demonstrate that PPI networks of many species are well-fit by several models not previously tested. In addition, we model several viral PPI networks for the first time and demonstrate an exceptionally good fit between the data and theoretical models. Contact : natasha@imperial.ac.uk
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
    Topics: Biology , Computer Science , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Graphlet-based measures are suitable for biological network comparison (2013)
    Oxford University Press
    Details
    Publication Date: 2013-01-23
    Print ISSN: 1367-4803
    Electronic ISSN: 1460-2059
    Topics: Biology , Computer Science , Medicine
    Published by Oxford University Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...