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Search Results: 1 - 10 of 155819 matches for " Samuel H. Payne "
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Proteogenomic Analysis of Bacteria and Archaea: A 46 Organism Case Study
Eli Venter, Richard D. Smith, Samuel H. Payne
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0027587
Abstract: Experimental evidence is increasingly being used to reassess the quality and accuracy of genome annotation. Proteomics data used for this purpose, called proteogenomics, can alleviate many of the problematic areas of genome annotation, e.g. short protein validation and start site assignment. We performed a proteogenomic analysis of 46 genomes spanning eight bacterial and archaeal phyla across the tree of life. These diverse datasets facilitated the development of a robust approach for proteogenomics that is functional across genomes varying in %GC, gene content, proteomic sampling depth, phylogeny, and genome size. In addition to finding evidence for 682 novel proteins, 1336 new start sites, and numerous dubious genes, we discovered sites of post-translational maturation in the form of proteolytic cleavage of 1175 signal peptides. The number of novel proteins per genome is highly variable (median 7, mean 15, stdev 20). Moreover, comparison of novel genes with the current genes did not reveal any consistent abnormalities. Thus, we conclude that proteogenomics fulfills a yet to be understood deficiency in gene prediction. With the adoption of new sequencing technologies which have higher error rates than Sanger-based methods and the advances in proteomics, proteogenomics may become even more important in the future.
A proteogenomic update to Yersinia: enhancing genome annotation
Samuel H Payne, Shih-Ting Huang, Rembert Pieper
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-460
Abstract: The application of experimental proteomics data to genome annotation, called proteogenomics, can quickly and efficiently discover misannotations, yielding a more accurate and complete genome annotation. We present a comprehensive proteogenomic analysis of the plague bacterium, Yersinia pestis KIM. We discover non-annotated genes, correct protein boundaries, remove spuriously annotated ORFs, and make major advances towards accurate identification of signal peptides. Finally, we apply our data to 21 other Yersinia genomes, correcting and enhancing their annotations.In total, 141 gene models were altered and have been updated in RefSeq and Genbank, which can be accessed seamlessly through any NCBI tool (e.g. blast) or downloaded directly. Along with the improved gene models we discover new, more accurate means of identifying signal peptides in proteomics data.Yersinia pestis, a Gram-negative bacterium, is the causative agent of the bubonic and pneumonic plague. The pathogenic lifestyle of this microbe involves two distinct life stages, one in the flea vector, the other in mammalian hosts, primarily rodents [1]. Y. pestis recently speciated from Y. pseudotuberculosis, acquiring two pathogenic plasmids and a chromosomal pathogenicity island. Seven Y. pestis genomes have been sequenced to completion, along with five other Yersinia sequences. Numerous other Yersinia have been sequenced to draft quality.Genome annotation is often divided into two sequential phases, finding genes and assigning function. Most prokaryotic genome annotation pipelines consist of automated gene finding, corroborated by limited homology comparisons. As such they lack any experimental validation of primary structure. Fundamentally, an accurate primary structure implies finding the correct start/stop of the gene, which may be erroneously predicted for 20% of genes in some bacterial and archaeal genomes [2,3]. But it also includes recognizing any true frame-shifting events, which must be delineated f
Top-Down Characterization of the Post-Translationally Modified Intact Periplasmic Proteome from the Bacterium Novosphingobium aromaticivorans
Si Wu,Roslyn N. Brown,Samuel H. Payne,Da Meng
International Journal of Proteomics , 2013, DOI: 10.1155/2013/279590
Abstract:
Experimental annotation of post-translational features and translated coding regions in the pathogen Salmonella Typhimurium
Charles Ansong, Nikola Toli?, Samuel O Purvine, Steffen Porwollik, Marcus Jones, Hyunjin Yoon, Samuel H Payne, Jessica L Martin, Meagan C Burnet, Matthew E Monroe, Pratap Venepally, Richard D Smith, Scott N Peterson, Fred Heffron, Michael McClelland, Joshua N Adkins
BMC Genomics , 2011, DOI: 10.1186/1471-2164-12-433
Abstract: We experimentally annotated the bacterial pathogen Salmonella Typhimurium 14028, using "shotgun" proteomics to accurately uncover the translational landscape and post-translational features. The data provide protein-level experimental validation for approximately half of the predicted protein-coding genes in Salmonella and suggest revisions to several genes that appear to have incorrectly assigned translational start sites, including a potential novel alternate start codon. Additionally, we uncovered 12 non-annotated genes missed by gene prediction programs, as well as evidence suggesting a role for one of these novel ORFs in Salmonella pathogenesis. We also characterized post-translational features in the Salmonella genome, including chemical modifications and proteolytic cleavages. We find that bacteria have a much larger and more complex repertoire of chemical modifications than previously thought including several novel modifications. Our in vivo proteolysis data identified more than 130 signal peptide and N-terminal methionine cleavage events critical for protein function.This work highlights several ways in which application of proteomics data can improve the quality of genome annotations to facilitate novel biological insights and provides a comprehensive proteome map of Salmonella as a resource for systems analysis.Many aspects of modern biological research are dependent on accurate identification of the protein-coding genes in each genome, as well as the nature of the mature functional protein products, a process commonly referred to as genome annotation. With the exponential increase in the number of sequenced prokaryotic genomes afforded by advances in genome sequencing technologies over the last decade, present day prokaryotic genome annotation is essentially an automated high-throughput process that relies heavily on de novo gene prediction programs [1-3].While de novo gene prediction programs have significantly improved for prokaryotic genomes consider
Characterizing the Escherichia coli O157:H7 Proteome Including Protein Associations with Higher Order Assemblies
Rembert Pieper, Quanshun Zhang, David J. Clark, Shih-Ting Huang, Moo-Jin Suh, John C. Braisted, Samuel H. Payne, Robert D. Fleischmann, Scott N. Peterson, Saul Tzipori
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0026554
Abstract: Background The recent outbreak of severe infections with Shiga toxin (Stx) producing Escherichia coli (STEC) serotype O104:H4 highlights the need to understand horizontal gene transfer among E. coli strains, identify novel virulence factors and elucidate their pathogenesis. Quantitative shotgun proteomics can contribute to such objectives, allowing insights into the part of the genome translated into proteins and the connectivity of biochemical pathways and higher order assemblies of proteins at the subcellular level. Methodology/Principal Findings We examined protein profiles in cell lysate fractions of STEC strain 86-24 (serotype O157:H7), following growth in cell culture or bacterial isolation from intestines of infected piglets, in the context of functionally and structurally characterized biochemical pathways of E. coli. Protein solubilization in the presence of Triton X-100, EDTA and high salt was followed by size exclusion chromatography into the approximate Mr ranges greater than 280 kDa, 280-80 kDa and 80-10 kDa. Peptide mixtures resulting from these and the insoluble fraction were analyzed by quantitative 2D-LC-nESI-MS/MS. Of the 2521 proteins identified at a 1% false discovery rate, representing 47% of all predicted E. coli O157:H7 gene products, the majority of integral membrane proteins were enriched in the high Mr fraction. Hundreds of proteins were enriched in a Mr range higher than that predicted for a monomer supporting their participation in protein complexes. The insoluble STEC fraction revealed enrichment of aggregation-prone proteins, including many that are part of large structure/function entities such as the ribosome, cytoskeleton and O-antigen biosynthesis cluster. Significance Nearly all E. coli O157:H7 proteins encoded by prophage regions were expressed at low abundance levels or not detected. Comparative quantitative analyses of proteins from distinct cell lysate fractions allowed us to associate uncharacterized proteins with membrane attachment, potential participation in stable protein complexes, and susceptibility to aggregation as part of larger structural assemblies.
VESPA: software to facilitate genomic annotation of prokaryotic organisms through integration of proteomic and transcriptomic data
Elena S Peterson, Lee Ann McCue, Alexandra C Schrimpe-Rutledge, Jeffrey L Jensen, Hyunjoo Walker, Markus A Kobold, Samantha R Webb, Samuel H Payne, Charles Ansong, Joshua N Adkins, William R Cannon, Bobbie-Jo M Webb-Robertson
BMC Genomics , 2012, DOI: 10.1186/1471-2164-13-131
Abstract: VESPA is a desktop Java? application that integrates high-throughput proteomics data (peptide-centric) and transcriptomics (probe or RNA-Seq) data into a genomic context, all of which can be visualized at three levels of genomic resolution. Data is interrogated via searches linked to the genome visualizations to find regions with high likelihood of mis-annotation. Search results are linked to exports for further validation outside of VESPA or potential coding-regions can be analyzed concurrently with the software through interaction with BLAST. VESPA is demonstrated on two use cases (Yersinia pestis Pestoides F and Synechococcus sp. PCC 7002) to demonstrate the rapid manner in which mis-annotations can be found and explored in VESPA using either proteomics data alone, or in combination with transcriptomic data.VESPA is an interactive visual analytics tool that integrates high-throughput data into a genomic context to facilitate the discovery of structural mis-annotations in prokaryotic genomes. Data is evaluated via visual analysis across multiple levels of genomic resolution, linked searches and interaction with existing bioinformatics tools. We highlight the novel functionality of VESPA and core programming requirements for visualization of these large heterogeneous datasets for a client-side application. The software is freely available at https://www.biopilot.org/docs/Software/Vespa.php webcite.High throughput (HTP) molecular technologies are at the core of new capabilities to derive genomic-level profiles oforganisms [1,2]. One challenge often not addressed in the context of HTP technologies is the relationship of the analyses to the defined structural annotation of the genome. For example, the accuracy of global bottom-up proteomics is directly dependent upon accurately defined open reading frames (ORFs), because spectra are matched directly to an in silico enzymatic digest of the predicted proteins. Although a well-annotated genome is typically needed to anal
Top-Down Characterization of the Post-Translationally Modified Intact Periplasmic Proteome from the Bacterium Novosphingobium aromaticivorans
Si Wu,Roslyn N. Brown,Samuel H. Payne,Da Meng,Rui Zhao,Nikola Toli?,Li Cao,Anil Shukla,Matthew E. Monroe,Ronald J. Moore,Mary S. Lipton,Ljiljana Pa?a-Toli?
International Journal of Proteomics , 2013, DOI: 10.1155/2013/279590
Abstract: The periplasm of Gram-negative bacteria is a dynamic and physiologically important subcellular compartment where the constant exposure to potential environmental insults amplifies the need for proper protein folding and modifications. Top-down proteomics analysis of the periplasmic fraction at the intact protein level provides unrestricted characterization and annotation of the periplasmic proteome, including the post-translational modifications (PTMs) on these proteins. Here, we used single-dimension ultra-high pressure liquid chromatography coupled with the Fourier transform mass spectrometry (FTMS) to investigate the intact periplasmic proteome of Novosphingobium aromaticivorans. Our top-down analysis provided the confident identification of 55 proteins in the periplasm and characterized their PTMs including signal peptide removal, N-terminal methionine excision, acetylation, glutathionylation, pyroglutamate, and disulfide bond formation. This study provides the first experimental evidence for the expression and periplasmic localization of many hypothetical and uncharacterized proteins and the first unrestrictive, large-scale data on PTMs in the bacterial periplasm. 1. Introduction The periplasm of Gram-negative bacteria is a hydrated gel located between the cytoplasmic and outer membranes and is comprised of peptidoglycan (cell wall), proteins, carbohydrates, and small solutes [1–3]. The periplasm is a dynamic subcellular compartment important for trafficking of molecules into and out of cells, maintaining cellular osmotic balance, envelope structure, responding to environmental cues and stresses, electron transport, xenobiotic metabolism, and protein folding and modification [4]. The periplasm provides a good model system to study protein biogenesis, composition, sorting, and modification at the molecular level. Indeed, it is analogous in many ways to the endoplasmic reticulum of eukaryotic cells in terms of transport, folding, and quality control [3]. Localization to the periplasm and beyond often involves an N-terminal secretion signal that targets the protein for translocation across the cytoplasmic membrane via the general secretory pathway [5]. These secretion signals (also known as signal peptides) are cleaved by signal peptidases located in the cytoplasmic membrane [6]. Thus, it is expected that signal peptide cleavage is a common modification in the periplasmic proteome. Compared to the cytoplasm, the periplasm is more vulnerable to changes in pH, temperature, and osmolarity in the external environment [4, 7, 8]. For structural stability in
Comparative Omics-Driven Genome Annotation Refinement: Application across Yersiniae
Alexandra C. Schrimpe-Rutledge, Marcus B. Jones, Sadhana Chauhan, Samuel O. Purvine, James A. Sanford, Matthew E. Monroe, Heather M. Brewer, Samuel H. Payne, Charles Ansong, Bryan C. Frank, Richard D. Smith, Scott N. Peterson, Vladimir L. Motin, Joshua N. Adkins
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0033903
Abstract: Genome sequencing continues to be a rapidly evolving technology, yet most downstream aspects of genome annotation pipelines remain relatively stable or are even being abandoned. The annotation process is now performed almost exclusively in an automated fashion to balance the large number of sequences generated. One possible way of reducing errors inherent to automated computational annotations is to apply data from omics measurements (i.e. transcriptional and proteomic) to the un-annotated genome with a proteogenomic-based approach. Here, the concept of annotation refinement has been extended to include a comparative assessment of genomes across closely related species. Transcriptomic and proteomic data derived from highly similar pathogenic Yersiniae (Y. pestis CO92, Y. pestis Pestoides F, and Y. pseudotuberculosis PB1/+) was used to demonstrate a comprehensive comparative omic-based annotation methodology. Peptide and oligo measurements experimentally validated the expression of nearly 40% of each strain's predicted proteome and revealed the identification of 28 novel and 68 incorrect (i.e., observed frameshifts, extended start sites, and translated pseudogenes) protein-coding sequences within the three current genome annotations. Gene loss is presumed to play a major role in Y. pestis acquiring its niche as a virulent pathogen, thus the discovery of many translated pseudogenes, including the insertion-ablated argD, underscores a need for functional analyses to investigate hypotheses related to divergence. Refinements included the discovery of a seemingly essential ribosomal protein, several virulence-associated factors, a transcriptional regulator, and many hypothetical proteins that were missed during annotation.
HI Observations of the starburst galaxy NGC 2146
A. Taramopoulos,H. Payne,F. H. Briggs
Physics , 2000, DOI: 10.1051/0004-6361:20000143
Abstract: NGC 2146 is a peculiar spiral galaxy which is currently undergoing a major burst of star formation and is immersed in a extended HI structure that has morphological and kinematical resemblence to a strong tidal interaction. This paper reports aperture synthesis observations carried out in the 21cm line with the Very Large Array (VLA - The National Radio Astronomy Observatory (NRAO) is operated by Associated Universities, Inc. under cooperative agreement with the National Science Foundation.) of two fields positioned to optimally cover the HI streams to the north and south of the galaxy, along with a 300 ft total power spectral mapping program to recover the low surface brightness extended emission. The observations reveal elongated streams of neutral hydrogen towards both the north and the south of the optical galaxy extending out up to 6 Holmberg radii. The streams are not in the principle plane of rotation of the galaxy, but instead are suggestive of a tidal interaction between NGC 2146 and a LSB companion that was destroyed by the encounter and remains undetected at optical wavelengths. Part of the southern stream is turning back to fall into the main galaxy, where it will create a long-lived warp in the HI disk of NGC 2146. Analysis of the trajectory of the outlying gas suggests that the closest encounter took place about 0.8 billion years ago and that infall of debris will continue for a similar time span.
Prophylactic Breast Bud Radiotherapy for Patients Taking Bicalutamide: Should This Still Be Practised for Patients with Prostate Cancer?
R. Lewis,A. Cassoni,H. Payne
Case Reports in Oncological Medicine , 2012, DOI: 10.1155/2012/239269
Abstract: Prophylactic breast bud radiotherapy is used to prevent gynaecomastia and mastalgia in patients with prostate cancer who are being treated with antiandrogen and oestrogen therapy. Here a case is presented of a patient who developed soft-tissue sarcoma of the breast subsequent to breast bud radiotherapy prior to bicalutamide hormone treatment. Bicalutamide is often prescribed for younger men in the adjuvant setting or as monotherapy for locally advanced disease. The data regarding the efficacy of prophylactic breast bud radiotherapy is reviewed, and it is proposed that alternative therapies should be considered such as tamoxifen.
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