2051
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Martínez-Montiel N, Morales-Lara L, Hernández-Pérez JM, Martínez-Contreras RD. In Silico Analysis of the Structural and Biochemical Features of the NMD Factor UPF1 in Ustilago maydis. PLoS One 2016; 11:e0148191. [PMID: 26863136 PMCID: PMC4749658 DOI: 10.1371/journal.pone.0148191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/14/2016] [Indexed: 11/23/2022] Open
Abstract
The molecular mechanisms regulating the accuracy of gene expression are still not fully understood. Among these mechanisms, Nonsense-mediated Decay (NMD) is a quality control process that detects post-transcriptionally abnormal transcripts and leads them to degradation. The UPF1 protein lays at the heart of NMD as shown by several structural and functional features reported for this factor mainly for Homo sapiens and Saccharomyces cerevisiae. This process is highly conserved in eukaryotes but functional diversity can be observed in various species. Ustilago maydis is a basidiomycete and the best-known smut, which has become a model to study molecular and cellular eukaryotic mechanisms. In this study, we performed in silico analysis to investigate the structural and biochemical properties of the putative UPF1 homolog in Ustilago maydis. The putative homolog for UPF1 was recognized in the annotated genome for the basidiomycete, exhibiting 66% identity with its human counterpart at the protein level. The known structural and functional domains characteristic of UPF1 homologs were also found. Based on the crystal structures available for UPF1, we constructed different three-dimensional models for umUPF1 in order to analyze the secondary and tertiary structural features of this factor. Using these models, we studied the spatial arrangement of umUPF1 and its capability to interact with UPF2. Moreover, we identified the critical amino acids that mediate the interaction of umUPF1 with UPF2, ATP, RNA and with UPF1 itself. Mutating these amino acids in silico showed an important effect over the native structure. Finally, we performed molecular dynamic simulations for UPF1 proteins from H. sapiens and U. maydis and the results obtained show a similar behavior and physicochemical properties for the protein in both organisms. Overall, our results indicate that the putative UPF1 identified in U. maydis shows a very similar sequence, structural organization, mechanical stability, physicochemical properties and spatial organization in comparison to the NMD factor depicted for Homo sapiens. These observations strongly support the notion that human and fungal UPF1 could perform equivalent biological activities.
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Affiliation(s)
- Nancy Martínez-Montiel
- Laboratorio de Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | - Laura Morales-Lara
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México
| | | | - Rebeca D. Martínez-Contreras
- Laboratorio de Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, México
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2052
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Davie JR, Xu W, Delcuve GP. Histone H3K4 trimethylation: dynamic interplay with pre-mRNA splicing. Biochem Cell Biol 2016; 94:1-11. [DOI: 10.1139/bcb-2015-0065] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Histone H3 lysine 4 trimethylation (H3K4me3) is often stated as a mark of transcriptionally active promoters. However, closer study of the positioning of H3K4me3 shows the mark locating primarily after the first exon at the 5′ splice site and overlapping with a CpG island in mammalian cells. There are several enzyme complexes that are involved in the placement of the H3K4me3 mark, including multiple protein complexes containing SETD1A, SETD1B, and MLL1 enzymes (writers). CXXC1, which is associated with SETD1A and SETD1B, target these enzymes to unmethylated CpG islands. Lysine demethylases (KDM5 family members, erasers) demethylate H3K4me3. The H3K4me3 mark is recognized by several proteins (readers), including lysine acetyltransferase complexes, chromatin remodelers, and RNA bound proteins involved in pre-mRNA splicing. Interestingly, attenuation of H3K4me3 impacts pre-mRNA splicing, and inhibition of pre-mRNA splicing attenuates H3K4me3.
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Affiliation(s)
- James R. Davie
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
| | - Wayne Xu
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
| | - Genevieve P. Delcuve
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
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2053
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Mayfield JE, Burkholder NT, Zhang YJ. Dephosphorylating eukaryotic RNA polymerase II. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:372-87. [PMID: 26779935 DOI: 10.1016/j.bbapap.2016.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/20/2022]
Abstract
The phosphorylation state of the C-terminal domain of RNA polymerase II is required for the temporal and spatial recruitment of various factors that mediate transcription and RNA processing throughout the transcriptional cycle. Therefore, changes in CTD phosphorylation by site-specific kinases/phosphatases are critical for the accurate transmission of information during transcription. Unlike kinases, CTD phosphatases have been traditionally neglected as they are thought to act as passive negative regulators that remove all phosphate marks at the conclusion of transcription. This over-simplified view has been disputed in recent years and new data assert the active and regulatory role phosphatases play in transcription. We now know that CTD phosphatases ensure the proper transition between different stages of transcription, balance the distribution of phosphorylation for accurate termination and re-initiation, and prevent inappropriate expression of certain genes. In this review, we focus on the specific roles of CTD phosphatases in regulating transcription. In particular, we emphasize how specificity and timing of dephosphorylation are achieved for these phosphatases and consider the various regulatory factors that affect these dynamics.
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Affiliation(s)
- Joshua E Mayfield
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Nathaniel T Burkholder
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Yan Jessie Zhang
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
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2054
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Liu F, Koval M, Ranganathan S, Fanayan S, Hancock WS, Lundberg EK, Beavis RC, Lane L, Duek P, McQuade L, Kelleher NL, Baker MS. Systems Proteomics View of the Endogenous Human Claudin Protein Family. J Proteome Res 2016; 15:339-59. [PMID: 26680015 DOI: 10.1021/acs.jproteome.5b00769] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Claudins are the major transmembrane protein components of tight junctions in human endothelia and epithelia. Tissue-specific expression of claudin members suggests that this protein family is not only essential for sustaining the role of tight junctions in cell permeability control but also vital in organizing cell contact signaling by protein-protein interactions. How this protein family is collectively processed and regulated is key to understanding the role of junctional proteins in preserving cell identity and tissue integrity. The focus of this review is to first provide a brief overview of the functional context, on the basis of the extensive body of claudin biology research that has been thoroughly reviewed, for endogenous human claudin members and then ascertain existing and future proteomics techniques that may be applicable to systematically characterizing the chemical forms and interacting protein partners of this protein family in human. The ability to elucidate claudin-based signaling networks may provide new insight into cell development and differentiation programs that are crucial to tissue stability and manipulation.
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Affiliation(s)
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, and Department of Cell Biology, Emory University School of Medicine , 205 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, Georgia 30322, United States
| | | | | | - William S Hancock
- Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Emma K Lundberg
- SciLifeLab, School of Biotechnology, Royal Institute of Technology (KTH) , SE-171 21 Solna, Stockholm, Sweden
| | - Ronald C Beavis
- Department of Biochemistry and Medical Genetics, University of Manitoba , 744 Bannatyne Avenue, Winnipeg, Manitoba R3E 0W3, Canada
| | - Lydie Lane
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | - Paula Duek
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | | | - Neil L Kelleher
- Department of Chemistry, Department of Molecular Biosciences, and Proteomics Center of Excellence, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
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2055
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Guharoy M, Bhowmick P, Sallam M, Tompa P. Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system. Nat Commun 2016; 7:10239. [PMID: 26732515 PMCID: PMC4729826 DOI: 10.1038/ncomms10239] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 11/17/2015] [Indexed: 12/26/2022] Open
Abstract
Specific signals (degrons) regulate protein turnover mediated by the ubiquitin-proteasome system. Here we systematically analyse known degrons and propose a tripartite model comprising the following: (1) a primary degron (peptide motif) that specifies substrate recognition by cognate E3 ubiquitin ligases, (2) secondary site(s) comprising a single or multiple neighbouring ubiquitinated lysine(s) and (3) a structurally disordered segment that initiates substrate unfolding at the 26S proteasome. Primary degron sequences are conserved among orthologues and occur in structurally disordered regions that undergo E3-induced folding-on-binding. Posttranslational modifications can switch primary degrons into E3-binding-competent states, thereby integrating degradation with signalling pathways. Degradation-linked lysines tend to be located within disordered segments that also initiate substrate degradation by effective proteasomal engagement. Many characterized mutations and alternative isoforms with abrogated degron components are implicated in disease. These effects result from increased protein stability and interactome rewiring. The distributed nature of degrons ensures regulation, specificity and combinatorial control of degradation.
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Affiliation(s)
- Mainak Guharoy
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Pallab Bhowmick
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Mohamed Sallam
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
| | - Peter Tompa
- VIB Structural Biology Research Center (SBRC), Vrije Universiteit Brussel (VUB), Building E, Pleinlaan 2, 1050 Brussels, Belgium
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Hungary
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2056
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Polo A, Colonna G, Guariniello S, Ciliberto G, Costantini S. Deducing the functional characteristics of the human selenoprotein SELK from the structural properties of its intrinsically disordered C-terminal domain. MOLECULAR BIOSYSTEMS 2016; 12:758-72. [PMID: 26735936 DOI: 10.1039/c5mb00679a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The intrinsically disordered proteins (IDPs) cannot be described by a single structural representation but, due to their high structural fluctuation, through conformational ensembles. Certainly, molecular dynamics (MD) simulations represent a useful tool to study their different conformations capturing the conformational distribution. Our group is focusing on the structural characterization of proteins belonging to the seleno-proteome due to their involvement in cancer. They present disordered domains central for their biological function, and, in particular, SELK is a single-pass transmembrane protein that resides in the endoplasmic reticulum membrane (ER) with a C-terminal domain exposed to the cytoplasm that is known to interact with different components of the endoplasmic reticulum associated to the protein degradation (ERAD) pathway. This protein is found to be up-expressed in hepatocellular carcinoma and in other cancers. In this work we performed a detailed analysis of the C-terminal domain sequence of SELK and discovered that it is characterized by many prolines, and four negatively and eleven positively charged residues, which are crucial for its biological activity. This region can be considered as a weak polyelectrolyte and, specifically, a polycation, with high disordered propensity and different phosphorylation sites dislocated along the sequence. Then, we modeled its three-dimensional structure by performing MD simulations in water at neutral pH to analyze the structural stability as well as to identify the presence of HUB residues that play a key structural role as evidenced by the residue-residue interaction network analysis. Through this approach, we demonstrate that the C-terminal domain of SELK (i) presents a poor content of regular secondary structure elements, (ii) is dynamically stabilized by a network of intra-molecular H-bonds and H-bonds with water molecules, (iii) is highly fluctuating and, therefore, can be described only through a conformational ensemble, where we evidenced a distribution of equilibrium conformers which continuously inter-change their conformations. Finally to verify the specific role played by the negative charges, we also performed MD simulations at acidic pH. Overall, all the obtained results evidenced that SELK has the dynamic structural features to be defined as a HUB protein able to interact with multiple members. Therefore, considering the possible role that this protein can have in cancer development and progression, it can represent a target for drug design studies.
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Affiliation(s)
- Andrea Polo
- Servizio di Informatica Medica, Azienda Ospedaliera Universitaria, Seconda Università di Napoli, Napoli, Italy
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2057
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Tym JE, Mitsopoulos C, Coker EA, Razaz P, Schierz AC, Antolin AA, Al-Lazikani B. canSAR: an updated cancer research and drug discovery knowledgebase. Nucleic Acids Res 2016; 44:D938-43. [PMID: 26673713 PMCID: PMC4702774 DOI: 10.1093/nar/gkv1030] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 09/28/2015] [Indexed: 12/21/2022] Open
Abstract
canSAR (http://cansar.icr.ac.uk) is a publicly available, multidisciplinary, cancer-focused knowledgebase developed to support cancer translational research and drug discovery. canSAR integrates genomic, protein, pharmacological, drug and chemical data with structural biology, protein networks and druggability data. canSAR is widely used to rapidly access information and help interpret experimental data in a translational and drug discovery context. Here we describe major enhancements to canSAR including new data, improved search and browsing capabilities, new disease and cancer cell line summaries and new and enhanced batch analysis tools.
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Affiliation(s)
- Joseph E Tym
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Costas Mitsopoulos
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Elizabeth A Coker
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Parisa Razaz
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Amanda C Schierz
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Albert A Antolin
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
| | - Bissan Al-Lazikani
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, SM2 5NG, UK
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2058
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Vaudel M, Verheggen K, Csordas A, Raeder H, Berven FS, Martens L, Vizcaíno JA, Barsnes H. Exploring the potential of public proteomics data. Proteomics 2016; 16:214-25. [PMID: 26449181 PMCID: PMC4738454 DOI: 10.1002/pmic.201500295] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/25/2015] [Accepted: 09/28/2015] [Indexed: 12/22/2022]
Abstract
In a global effort for scientific transparency, it has become feasible and good practice to share experimental data supporting novel findings. Consequently, the amount of publicly available MS-based proteomics data has grown substantially in recent years. With some notable exceptions, this extensive material has however largely been left untouched. The time has now come for the proteomics community to utilize this potential gold mine for new discoveries, and uncover its untapped potential. In this review, we provide a brief history of the sharing of proteomics data, showing ways in which publicly available proteomics data are already being (re-)used, and outline potential future opportunities based on four different usage types: use, reuse, reprocess, and repurpose. We thus aim to assist the proteomics community in stepping up to the challenge, and to make the most of the rapidly increasing amount of public proteomics data.
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Affiliation(s)
- Marc Vaudel
- Proteomics Unit, Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Kenneth Verheggen
- Medical Biotechnology Center, VIB, Ghent, Belgium
- Department of Biochemistry, Ghent University, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Attila Csordas
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Helge Raeder
- Department of Clinical Science, KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
| | - Frode S Berven
- Proteomics Unit, Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Clinical Medicine, KG Jebsen Centre for Multiple Sclerosis Research, University of Bergen, Bergen, Norway
| | - Lennart Martens
- Medical Biotechnology Center, VIB, Ghent, Belgium
- Department of Biochemistry, Ghent University, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium
| | - Juan A Vizcaíno
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Harald Barsnes
- Proteomics Unit, Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Clinical Science, KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
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2059
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Kusonmano K. Gene Expression Analysis Through Network Biology: Bioinformatics Approaches. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 160:15-32. [PMID: 27830311 DOI: 10.1007/10_2016_44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Following the availability of high-throughput technologies, vast amounts of biological data have been generated. Gene expression is one example of the popular data that has been utilized for studying cellular systems in the transcriptional level. Several bioinformatics approaches have been developed to analyze such data. A typical expression analysis identifies a ranked list of individual significant differentially expressed genes between two conditions of interest. However, it has been accepted that biomolecules in a living organism are working together and interacting with each other. Study through network analysis could be complementary to typical expression analysis and provides more contexts to understanding the biological systems. Conversely, expression data could provide clues to functional links between biomolecules in biological networks. In this chapter, bioinformatics approaches to analyze expression data in network levels including basic concepts of network biology are described. Different concepts to integrate expression data with interactome data and example studies are explained.
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Affiliation(s)
- Kanthida Kusonmano
- Bioinformatics and Systems Biology Program, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok, Thailand.
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2060
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Hof F. Host–guest chemistry that directly targets lysine methylation: synthetic host molecules as alternatives to bio-reagents. Chem Commun (Camb) 2016; 52:10093-108. [DOI: 10.1039/c6cc04771h] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Post-translational methylation regulates the function of hundreds of proteins in profound ways, and is the target of many efforts to use host–guest chemistry to solve biochemical and biological problems.
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Affiliation(s)
- Fraser Hof
- Department of Chemistry
- University of Victoria
- V8W3V6 Canada
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2061
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Abstract
Five syndromes share predominantly hyperplastic glands with a primary excess of hormones: neonatal severe primary hyperparathyroidism, from homozygous mutated CASR, begins severely in utero; congenital non-autoimmune thyrotoxicosis, from mutated TSHR, varies from severe with fetal onset to mild with adult onset; familial male-limited precocious puberty, from mutated LHR, expresses testosterone oversecretion in young boys; hereditary ovarian hyperstimulation syndrome, from mutated FSHR, expresses symptomatic systemic vascular permeabilities during pregnancy; and familial hyperaldosteronism type IIIA, from mutated KCNJ5, presents in young children with hypertension and hypokalemia. The grouping of these five syndromes highlights predominant hyperplasia as a stable tissue endpoint and as their tissue stage for all of the hormone excess. Comparisons were made among this and two other groups of syndromes, forming a continuum of gland staging: predominant oversecretions express little or no hyperplasia; predominant hyperplasias express little or no neoplasia; and predominant neoplasias express nodules, adenomas, or cancers. Hyperplasias may progress (5 of 5) to neoplastic stages while predominant oversecretions rarely do (1 of 6; frequencies differ P<0.02). Hyperplasias do not show tumor multiplicity (0 of 5) unlike neoplasias that do (13 of 19; P<0.02). Hyperplasias express mutation of a plasma membrane-bound sensor (5 of 5), while neoplasias rarely do (3 of 14; P<0.002). In conclusion, the multiple distinguishing themes within the hyperplasias establish a robust pathophysiology. It has the shared and novel feature of mutant sensors in the plasma membrane, suggesting that these are major contributors to hyperplasia.
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Affiliation(s)
- Stephen J Marx
- Genetics and Endocrinology SectionNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10, Room 9C-103, Bethesda, Maryland 20892, USA
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2062
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Mahboubi H, Stochaj U. Quantitative analysis of the interplay between hsc70 and its co-chaperone HspBP1. PeerJ 2015; 3:e1530. [PMID: 26713263 PMCID: PMC4690350 DOI: 10.7717/peerj.1530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/02/2015] [Indexed: 01/28/2023] Open
Abstract
Background. Chaperones and their co-factors are components of a cellular network; they collaborate to maintain proteostasis under normal and harmful conditions. In particular, hsp70 family members and their co-chaperones are essential to repair damaged proteins. Co-chaperones are present in different subcellular compartments, where they modulate chaperone activities. Methods and Results. Our studies assessed the relationship between hsc70 and its co-factor HspBP1 in human cancer cells. HspBP1 promotes nucleotide exchange on hsc70, but has also chaperone-independent functions. We characterized the interplay between hsc70 and HspBP1 by quantitative confocal microscopy combined with automated image analyses and statistical evaluation. Stress and the recovery from insult changed significantly the subcellular distribution of hsc70, but had little effect on HspBP1. Single-cell measurements and regression analysis revealed that the links between the chaperone and its co-factor relied on (i) the physiological state of the cell and (ii) the subcellular compartment. As such, we identified a linear relationship and strong correlation between hsc70 and HspBP1 distribution in control and heat-shocked cells; this correlation changed in a compartment-specific fashion during the recovery from stress. Furthermore, we uncovered significant stress-induced changes in the colocalization between hsc70 and HspBP1 in the nucleus and cytoplasm. Discussion. Our quantitative approach defined novel properties of the co-chaperone HspBP1 as they relate to its interplay with hsc70. We propose that changes in cell physiology promote chaperone redistribution and thereby stimulate chaperone-independent functions of HspBP1.
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Affiliation(s)
- Hicham Mahboubi
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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2063
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Lee SH, Princz LN, Klügel MF, Habermann B, Pfander B, Biertümpfel C. Human Holliday junction resolvase GEN1 uses a chromodomain for efficient DNA recognition and cleavage. eLife 2015; 4:e12256. [PMID: 26682650 PMCID: PMC5039027 DOI: 10.7554/elife.12256] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/17/2015] [Indexed: 12/22/2022] Open
Abstract
Holliday junctions (HJs) are key DNA intermediates in homologous recombination. They link homologous DNA strands and have to be faithfully removed for proper DNA segregation and genome integrity. Here, we present the crystal structure of human HJ resolvase GEN1 complexed with DNA at 3.0 Å resolution. The GEN1 core is similar to other Rad2/XPG nucleases. However, unlike other members of the superfamily, GEN1 contains a chromodomain as an additional DNA interaction site. Chromodomains are known for their chromatin-targeting function in chromatin remodelers and histone(de)acetylases but they have not previously been found in nucleases. The GEN1 chromodomain directly contacts DNA and its truncation severely hampers GEN1's catalytic activity. Structure-guided mutations in vitro and in vivo in yeast validated our mechanistic findings. Our study provides the missing structure in the Rad2/XPG family and insights how a well-conserved nuclease core acquires versatility in recognizing diverse substrates for DNA repair and maintenance.
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Affiliation(s)
- Shun-Hsiao Lee
- Department of Structural Cell Biology, Molecular Mechanisms of DNA Repair, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Lissa Nicola Princz
- Department of Molecular Cell Biology, DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maren Felizitas Klügel
- Department of Structural Cell Biology, Molecular Mechanisms of DNA Repair, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Bianca Habermann
- Computational Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Boris Pfander
- Department of Molecular Cell Biology, DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christian Biertümpfel
- Department of Structural Cell Biology, Molecular Mechanisms of DNA Repair, Max Planck Institute of Biochemistry, Martinsried, Germany
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2064
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Wang H, Duan Y, Zhong W. ZrO2 Nanofiber as a Versatile Tool for Protein Analysis. ACS APPLIED MATERIALS & INTERFACES 2015; 7:26414-20. [PMID: 26571083 DOI: 10.1021/acsami.5b09348] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Phosphorylation is one of the most important post-translational modifications in proteins. Their essential roles in the regulation of cellular processes and alteration of protein-protein interaction networks have been actively studied. However, phosphorylated proteins are present at low abundance in cells, and ionization of the modified peptides is often suppressed by the more abundant species in mass spectrometry. Effective enrichment techniques are needed to remove the unmodified peptides and concentrate the phosphorylated ones before their identification and quantification. Herein, we prepared ZrO2 nanofibers by electrospinning, a straightforward and easy fabrication technique, and applied them to enrich phosphorylated peptides and proteins. The fibers showed good size homogeneity and porosity and could specifically bind to the phosphorylated peptides and proteins, allowing their separation from the unmodified analogues when present in either simple protein digests or highly complex cell lysates. The enrichment performance was superior to that of the commercially available nanoparticles. Moreover, modifying the solution pH could lead to selective adsorption of proteins with different pI values, suggesting the fibers' potential applicability in charge-based protein fractionation. Our results support that the electrospun ZrO2 nanofibers can serve as a versatile tool for protein analysis with great ease in preparation and handling.
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Affiliation(s)
- Hui Wang
- Department of Chemistry, University of California , Riverside, California, United States
| | - Yaokai Duan
- Department of Chemistry, University of California , Riverside, California, United States
| | - Wenwan Zhong
- Department of Chemistry, University of California , Riverside, California, United States
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2065
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Humphrey SJ, James DE, Mann M. Protein Phosphorylation: A Major Switch Mechanism for Metabolic Regulation. Trends Endocrinol Metab 2015; 26:676-687. [PMID: 26498855 DOI: 10.1016/j.tem.2015.09.013] [Citation(s) in RCA: 332] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/26/2015] [Accepted: 09/28/2015] [Indexed: 12/20/2022]
Abstract
Metabolism research is undergoing a renaissance because many diseases are increasingly recognized as being characterized by perturbations in intracellular metabolic regulation. Metabolic changes can be conferred through changes to the expression of metabolic enzymes, the concentrations of substrates or products that govern reaction kinetics, or post-translational modification (PTM) of the proteins that facilitate these reactions. On the 60th anniversary since its discovery, reversible protein phosphorylation is widely appreciated as an essential PTM regulating metabolism. With the ability to quantitatively measure dynamic changes in protein phosphorylation on a global scale - hereafter referred to as phosphoproteomics - we are now entering a new era in metabolism research, with mass spectrometry (MS)-based proteomics at the helm.
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Affiliation(s)
- Sean J Humphrey
- Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, Martinsried 82152, Germany
| | - David E James
- Charles Perkins Centre, School of Molecular Bioscience, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, Martinsried 82152, Germany.
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2066
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Current and Novel Aspects on the Non-lysosomal β-Glucosylceramidase GBA2. Neurochem Res 2015; 41:210-20. [DOI: 10.1007/s11064-015-1763-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 10/22/2022]
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2067
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Hu Z, Xu Z, Liao X, Yang X, Dong C, Luk K, Jin A, Lu H. Polo-like kinase 2 acting as a promoter in human tumor cells with an abundance of TAp73. Onco Targets Ther 2015; 8:3475-88. [PMID: 26640387 PMCID: PMC4662374 DOI: 10.2147/ott.s90302] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background TAp73, a member of the p53 tumor suppressor family, is frequently overexpressed in malignant tumors in humans. TAp73 abundance and phosphorylation modification result in variations in transcriptional activity. In a previous study, we found that the antitumor function of TAp73 was reactivated by dephosphorylation in head and neck squamous cell carcinomas. Polo-like kinase 2 (PLK2) displayed a close relationship with the p53 family in affecting the fate of cells. Herein, we investigate the hypothesis that PLK2 phosphorylates TAp73 and inhibits TAp73 function. Materials and methods Head and neck squamous cell carcinoma cell lines and osteosarcoma cell lines were used as natural models of the different expression levels of TAp73. Phosphorylation predictor software Scansite 3.0 and the predictor GPS-polo 1.0 were used to analyze the phosphorylation sites. Coimmunoprecipitation, phosphor-tag Western blot, metabolic labeling, and indirect immunofluorescence assays were used to determine the interactions between PLK2 and TAp73. TAp73 activity was assessed by Western blot and reverse transcription polymerase chain reaction, which we used to detect P21 and PUMA, both downstream genes of TAp73. The physiological effects of PLK2 cross talk with TAp73 on cell cycle progress and apoptosis were observed by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Results PLK2 binds to and phosphorylates TAp73. PLK2 phosphorylates TAp73 at residue Ser48 and prohibits TAp73 translocation to the nucleus. Additionally, PLK2 inhibition combined with a DNA-damaging drug upregulated p21 and PUMA mRNA expression to a greater extent than DNA-damaging drug treatment alone. Inhibiting PLK2 in TAp73-enriched cells strengthened the effects of the DNA-damaging drug on both G1 phase arrest and apoptosis. Pretreatment with TAp73-siRNA weakened these effects. Conclusion These findings reveal a novel PLK2 function (catalyzed phosphorylation of TAp73) which suppresses TAp73 functions. PLK2 promotes the survival of human tumor cells, a novel insight into the workings of malignant tumors characterized by TAp73 overexpression, and one that could speed the development of therapies.
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Affiliation(s)
- ZhengBo Hu
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - ZunYing Xu
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - XiaoHong Liao
- The State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Xiao Yang
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Cao Dong
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - KuaDi Luk
- Department of Orthopedics and Traumatology, The University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - AnMin Jin
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Hai Lu
- Department of Orthopedics, the Third Affiliated Hospital of the Southern Medical University, Guangzhou, Guangdong, People's Republic of China ; Academy of Orthopedics, Guangdong Province, People's Republic of China
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2068
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Huang KY, Su MG, Kao HJ, Hsieh YC, Jhong JH, Cheng KH, Huang HD, Lee TY. dbPTM 2016: 10-year anniversary of a resource for post-translational modification of proteins. Nucleic Acids Res 2015; 44:D435-46. [PMID: 26578568 PMCID: PMC4702878 DOI: 10.1093/nar/gkv1240] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/02/2015] [Indexed: 01/23/2023] Open
Abstract
Owing to the importance of the post-translational modifications (PTMs) of proteins in regulating biological processes, the dbPTM (http://dbPTM.mbc.nctu.edu.tw/) was developed as a comprehensive database of experimentally verified PTMs from several databases with annotations of potential PTMs for all UniProtKB protein entries. For this 10th anniversary of dbPTM, the updated resource provides not only a comprehensive dataset of experimentally verified PTMs, supported by the literature, but also an integrative interface for accessing all available databases and tools that are associated with PTM analysis. As well as collecting experimental PTM data from 14 public databases, this update manually curates over 12 000 modified peptides, including the emerging S-nitrosylation, S-glutathionylation and succinylation, from approximately 500 research articles, which were retrieved by text mining. As the number of available PTM prediction methods increases, this work compiles a non-homologous benchmark dataset to evaluate the predictive power of online PTM prediction tools. An increasing interest in the structural investigation of PTM substrate sites motivated the mapping of all experimental PTM peptides to protein entries of Protein Data Bank (PDB) based on database identifier and sequence identity, which enables users to examine spatially neighboring amino acids, solvent-accessible surface area and side-chain orientations for PTM substrate sites on tertiary structures. Since drug binding in PDB is annotated, this update identified over 1100 PTM sites that are associated with drug binding. The update also integrates metabolic pathways and protein-protein interactions to support the PTM network analysis for a group of proteins. Finally, the web interface is redesigned and enhanced to facilitate access to this resource.
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Affiliation(s)
- Kai-Yao Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Min-Gang Su
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Hui-Ju Kao
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Yun-Chung Hsieh
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Jhih-Hua Jhong
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Kuang-Hao Cheng
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan
| | - Hsien-Da Huang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Tzong-Yi Lee
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan 320, Taiwan Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan 320, Taiwan
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2069
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PDE4D phosphorylation: A coincidence detector integrating multiple signaling pathways. Cell Signal 2015; 28:719-24. [PMID: 26562185 DOI: 10.1016/j.cellsig.2015.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 11/24/2022]
Abstract
In Eukaryotes, more than 100 different phosphodiesterase (PDE) proteins serve to fine-tune cyclic nucleotide (cAMP and cGMP) signals and contribute to specificity of signaling. In mammals, PDEs are divided into 11 families, of which PDE4 represents the largest family. Four genes (pde4a, pde4b, pde4c and pde4d) encode for this class of enzymes in mammals and give rise to more than 20 variants. Within this family of genes, PDE4D was discovered on the basis of its regulatory properties and its induction by hormones and cAMP. PDE4D has often been used as the prototype PDE4 and large body of work has been generated on the biochemical, pharmacological, and physiological properties of this enzyme. This review covers the regulation of PDE4D by phosphorylation, the impact of this regulation in the context of the structure of this protein, and the functional consequences of this complex pattern of posttranslational modifications.
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2070
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Snider NT, Omary MB. Assays for Posttranslational Modifications of Intermediate Filament Proteins. Methods Enzymol 2015; 568:113-38. [PMID: 26795469 DOI: 10.1016/bs.mie.2015.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intermediate filament (IF) proteins are known to be regulated by a number of posttranslational modifications (PTMs). Phosphorylation is the best-studied IF PTM, whereas ubiquitination, sumoylation, acetylation, glycosylation, ADP-ribosylation, farnesylation, and transamidation are less understood in functional terms but are known to regulate specific IFs under various contexts. The number and diversity of IF PTMs is certain to grow along with rapid advances in proteomic technologies. Therefore, the need for a greater understanding of the implications of PTMs to the structure, organization, and function of the IF cytoskeleton has become more apparent with the increased availability of data from global profiling studies of normal and diseased specimens. This chapter will provide information on established methods for the isolation and monitoring of IF PTMs along with the key reagents that are necessary to carry out these experiments.
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Affiliation(s)
- Natasha T Snider
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina, USA.
| | - M Bishr Omary
- Department of Molecular & Integrative Physiology, Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA; VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
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2071
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Kwon OK, Sim J, Kim SJ, Sung E, Kim JY, Jeong TC, Lee S. Comprehensive Analysis of in Vivo Phosphoproteome of Mouse Liver Microsomes. J Proteome Res 2015; 14:5215-24. [PMID: 26487105 DOI: 10.1021/acs.jproteome.5b00812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Protein phosphorylation at serine, threonine, and tyrosine residues are some of the most widespread reversible post-translational modifications. Microsomes are vesicle-like bodies, not ordinarily present within living cells, which form from pieces of the endoplasmic reticulum (ER), plasma membrane, mitochondria, or Golgi apparatus of broken eukaryotic cells. Here we investigated the total phosphoproteome of mouse liver microsomes (MLMs) using TiO2 enrichment of phosphopeptides coupled to on-line 2D-LC-MS/MS. In total, 699 phosphorylation sites in 527 proteins were identified in MLMs. When compared with the current phosphoSitePlus database, 155 novel phosphoproteins were identified in MLM. The distributions of phosphosites were 89.4, 8.0, and 2.6% for phosphoserine, phosphotheronine, and phosphotyrosine, respectively. By Motif-X analysis, eight Ser motifs and one Thr motif were found, and five acidic, two basophilic-, and two proline-directed motifs were assigned. The potential functions of phosphoproteins in MLM were assigned by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. In GO annotation, phosphorylated microsomal proteins were involved in mRNA processing, mRNA metabolic processes, and RNA splicing. In the KEGG pathway analysis, phosphorylated microsomal proteins were highly enriched in ribosome protein processing in ER and ribosomes and in RNA transport. Furthermore, we determined that 52 and 23 phosphoproteins were potential substrates of cAMP-dependent protein kinase A and casein kinase II, respectively, many of which are 40S/60S ribosomal proteins. Overall, our results provide an overview of features of protein phosphorylation in MLMs that should be a valuable resource for the future understanding of protein synthesis or translation involving phosphorylation.
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Affiliation(s)
- Oh Kwang Kwon
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University , Daegu 41566, Republic of Korea
| | - JuHee Sim
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University , Daegu 41566, Republic of Korea
| | - Sun Ju Kim
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University , Daegu 41566, Republic of Korea
| | - Eunji Sung
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University , Daegu 41566, Republic of Korea
| | - Jin Young Kim
- Mass Spectrometry Research Center, Korea Basic Science Institute , Ochang, Chungbuk 28115, Republic of Korea
| | - Tae Cheon Jeong
- College of Pharmacy, Yeungnam University , Gyeongsan 38541, Republic of Korea
| | - Sangkyu Lee
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University , Daegu 41566, Republic of Korea
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2072
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Onwuli DO, Beltran-Alvarez P. An update on transcriptional and post-translational regulation of brain voltage-gated sodium channels. Amino Acids 2015; 48:641-651. [PMID: 26503606 PMCID: PMC4752963 DOI: 10.1007/s00726-015-2122-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 11/29/2022]
Abstract
Voltage-gated sodium channels are essential proteins in brain physiology, as they generate the sodium currents that initiate neuronal action potentials. Voltage-gated sodium channels expression, localisation and function are regulated by a range of transcriptional and post-translational mechanisms. Here, we review our understanding of regulation of brain voltage-gated sodium channels, in particular SCN1A (NaV1.1), SCN2A (NaV1.2), SCN3A (NaV1.3) and SCN8A (NaV1.6), by transcription factors, by alternative splicing, and by post-translational modifications. Our focus is strongly centred on recent research lines, and newly generated knowledge.
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Affiliation(s)
- Donatus O Onwuli
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK
| | - Pedro Beltran-Alvarez
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK.
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2073
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Systematic Analysis and Prediction of In Situ Cross Talk of O-GlcNAcylation and Phosphorylation. BIOMED RESEARCH INTERNATIONAL 2015; 2015:279823. [PMID: 26601103 PMCID: PMC4639640 DOI: 10.1155/2015/279823] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 10/01/2015] [Accepted: 10/04/2015] [Indexed: 01/17/2023]
Abstract
Reversible posttranslational modification (PTM) plays a very important role in biological process by changing properties of proteins. As many proteins are multiply modified by PTMs, cross talk of PTMs is becoming an intriguing topic and draws much attention. Currently, lots of evidences suggest that the PTMs work together to accomplish a specific biological function. However, both the general principles and underlying mechanism of PTM crosstalk are elusive. In this study, by using large-scale datasets we performed evolutionary conservation analysis, gene ontology enrichment, motif extraction of proteins with cross talk of O-GlcNAcylation and phosphorylation cooccurring on the same residue. We found that proteins with in situ O-GlcNAc/Phos cross talk were significantly enriched in some specific gene ontology terms and no obvious evolutionary pressure was observed. Moreover, 3 functional motifs associated with O-GlcNAc/Phos sites were extracted. We further used sequence features and GO features to predict O-GlcNAc/Phos cross talk sites based on phosphorylated sites and O-GlcNAcylated sites separately by the use of SVM model. The AUC of classifier based on phosphorylated sites is 0.896 and the other classifier based on GlcNAcylated sites is 0.843. Both classifiers achieved a relatively better performance compared with other existing methods.
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2074
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Valimberti I, Tiberti M, Lambrughi M, Sarcevic B, Papaleo E. E2 superfamily of ubiquitin-conjugating enzymes: constitutively active or activated through phosphorylation in the catalytic cleft. Sci Rep 2015; 5:14849. [PMID: 26463729 PMCID: PMC4604453 DOI: 10.1038/srep14849] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 08/19/2015] [Indexed: 12/22/2022] Open
Abstract
Protein phosphorylation is a modification that offers a dynamic and reversible mechanism to regulate the majority of cellular processes. Numerous diseases are associated with aberrant regulation of phosphorylation-induced switches. Phosphorylation is emerging as a mechanism to modulate ubiquitination by regulating key enzymes in this pathway. The molecular mechanisms underpinning how phosphorylation regulates ubiquitinating enzymes, however, are elusive. Here, we show the high conservation of a functional site in E2 ubiquitin-conjugating enzymes. In catalytically active E2s, this site contains aspartate or a phosphorylatable serine and we refer to it as the conserved E2 serine/aspartate (CES/D) site. Molecular simulations of substrate-bound and -unbound forms of wild type, mutant and phosphorylated E2s, provide atomistic insight into the role of the CES/D residue for optimal E2 activity. Both the size and charge of the side group at the site play a central role in aligning the substrate lysine toward E2 catalytic cysteine to control ubiquitination efficiency. The CES/D site contributes to the fingerprint of the E2 superfamily. We propose that E2 enzymes can be divided into constitutively active or regulated families. E2s characterized by an aspartate at the CES/D site signify constitutively active E2s, whereas those containing a serine can be regulated by phosphorylation.
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Affiliation(s)
- Ilaria Valimberti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan (Italy)
| | - Matteo Tiberti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan (Italy)
| | - Matteo Lambrughi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan (Italy)
| | - Boris Sarcevic
- Cell Cycle and Cancer Unit, St. Vincent's Institute of Medical Research and The Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Fitzroy, Melbourne, Victoria 3065, Australia
| | - Elena Papaleo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan (Italy)
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2075
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Perfetto L, Briganti L, Calderone A, Cerquone Perpetuini A, Iannuccelli M, Langone F, Licata L, Marinkovic M, Mattioni A, Pavlidou T, Peluso D, Petrilli LL, Pirrò S, Posca D, Santonico E, Silvestri A, Spada F, Castagnoli L, Cesareni G. SIGNOR: a database of causal relationships between biological entities. Nucleic Acids Res 2015; 44:D548-54. [PMID: 26467481 PMCID: PMC4702784 DOI: 10.1093/nar/gkv1048] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/02/2015] [Indexed: 12/25/2022] Open
Abstract
Assembly of large biochemical networks can be achieved by confronting new cell-specific experimental data with an interaction subspace constrained by prior literature evidence. The SIGnaling Network Open Resource, SIGNOR (available on line at http://signor.uniroma2.it), was developed to support such a strategy by providing a scaffold of prior experimental evidence of causal relationships between biological entities. The core of SIGNOR is a collection of approximately 12,000 manually-annotated causal relationships between over 2800 human proteins participating in signal transduction. Other entities annotated in SIGNOR are complexes, chemicals, phenotypes and stimuli. The information captured in SIGNOR can be represented as a signed directed graph illustrating the activation/inactivation relationships between signalling entities. Each entry is associated to the post-translational modifications that cause the activation/inactivation of the target proteins. More than 4900 modified residues causing a change in protein concentration or activity have been curated and linked to the modifying enzymes (about 351 human kinases and 94 phosphatases). Additional modifications such as ubiquitinations, sumoylations, acetylations and their effect on the modified target proteins are also annotated. This wealth of structured information can support experimental approaches based on multi-parametric analysis of cell systems after physiological or pathological perturbations and to assemble large logic models.
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Affiliation(s)
- Livia Perfetto
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | | | | | | | | | | | - Luana Licata
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | | | - Anna Mattioni
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | | | - Daniele Peluso
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | | | - Stefano Pirrò
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Daniela Posca
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Elena Santonico
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | | | - Filomena Spada
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Luisa Castagnoli
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Gianni Cesareni
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
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2076
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Howe V, Chua NK, Stevenson J, Brown AJ. The Regulatory Domain of Squalene Monooxygenase Contains a Re-entrant Loop and Senses Cholesterol via a Conformational Change. J Biol Chem 2015; 290:27533-44. [PMID: 26434806 DOI: 10.1074/jbc.m115.675181] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 11/06/2022] Open
Abstract
Squalene monooxygenase (SM) is an important control point in cholesterol synthesis beyond 3-hydroxy-3-methylglutaryl-CoA reductase. Although it is known to associate with the endoplasmic reticulum, its topology has not been determined. We have elucidated the membrane topology of the sterol-responsive domain of SM comprising the first 100 amino acids fused to GFP (SM N100-GFP) by determining the accessibility of 16 introduced cysteines to the cysteine-reactive, membrane-impermeable reagent PEG-maleimide. We have identified a region integrally associated with the endoplasmic reticulum membrane that is likely to interact with cholesterol or respond to cholesterol-induced membrane effects. By comparing cysteine accessibility with and without cholesterol treatment, we further present evidence to suggest that cholesterol induces a conformational change in SM N100-GFP. This change is likely to lead to its targeted degradation by the ubiquitin-proteasome system because degradation is blunted by treatment with the chemical chaperone glycerol, which retains SM N100-GFP in its native conformation. Furthermore, degradation can be disrupted by insertion of two N-terminal myc tags, implicating the N terminus in this process. Together, this information provides new molecular insights into the regulation of this critical control point in cholesterol synthesis.
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Affiliation(s)
- Vicky Howe
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
| | - Ngee Kiat Chua
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
| | - Julian Stevenson
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720
| | - Andrew J Brown
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
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2077
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Protein-specific imaging of posttranslational modifications. Curr Opin Chem Biol 2015; 28:156-63. [DOI: 10.1016/j.cbpa.2015.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/23/2015] [Accepted: 07/27/2015] [Indexed: 11/18/2022]
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2078
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Boylston JA, Sun J, Chen Y, Gucek M, Sack MN, Murphy E. Characterization of the cardiac succinylome and its role in ischemia-reperfusion injury. J Mol Cell Cardiol 2015; 88:73-81. [PMID: 26388266 DOI: 10.1016/j.yjmcc.2015.09.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/09/2015] [Accepted: 09/15/2015] [Indexed: 11/20/2022]
Abstract
Succinylation refers to modification of lysine residues with succinyl groups donated by succinyl-CoA. Sirtuin5 (Sirt5) is a mitochondrial NAD(+)-dependent deacylase that catalyzes the removal of succinyl groups from proteins. Sirt5 and protein succinylation are conserved across species, suggesting functional importance of the modification. Sirt5 loss impacts liver metabolism but the role of succinylation in the heart has not been explored. We combined affinity enrichment with proteomics and mass spectrometry to analyze total succinylated lysine content of mitochondria isolated from WT and Sirt5(-/-) mouse hearts. We identified 887 succinylated lysine residues in 184 proteins. 44 peptides (5 proteins) occurred uniquely in WT samples, 289 (46 proteins) in Sirt5(-/-) samples, and 554 (133 proteins) were common to both groups. The 46 unique proteins in Sirt5(-/-) heart participate in metabolic processes such as fatty acid β-oxidation (Eci2) and branched chain amino acid catabolism, and include respiratory chain proteins (Ndufa7, 12, 13, Dhsa). We performed label-free analysis of the peptides common to WT and Sirt5(-/-) hearts. 16 peptides from 9 proteins were significantly increased in Sirt5(-/-) by at least 30%. The adenine nucleotide transporter 1 showed the highest increase in succinylation in Sirt5(-/-) (108.4 fold). The data indicate that succinylation is widespread in the heart and enriched in metabolic pathways. We examined whether the loss of Sirt5 would impact ischemia-reperfusion (I/R) injury and we found an increase in infarct size in Sirt5(-/-) hearts compared to WT littermates (68.5(+)/-1.1% Sirt5(-/-) vs 39.6(+)/(-) 6.8% WT) following 20min of ischemia and 90-min reperfusion. We further demonstrate that I/R injury in Sirt5(-/-) heart is restored to WT levels by pretreatment with dimethyl malonate, a competitive inhibitor of succinate dehydrogenase (SDH), implicating alteration in SDH activity as causative of the injury.
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Affiliation(s)
| | - Junhui Sun
- Systems Biology Center, NHLBI, NIH, Bethesda, MD, United States
| | - Yong Chen
- Proteomics Core Facility, NHLBI, NIH, Bethesda, MD, United States
| | - Marjan Gucek
- Proteomics Core Facility, NHLBI, NIH, Bethesda, MD, United States
| | - Michael N Sack
- Center for Molecular Medicine, NHLBI, NIH, Bethesda, MD, United States
| | - Elizabeth Murphy
- Systems Biology Center, NHLBI, NIH, Bethesda, MD, United States.
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2079
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Kong S, Dong H, Song J, Thiruppathi M, Prabhakar BS, Qiu Q, Lin Z, Chini E, Zhang B, Fang D. Deleted in Breast Cancer 1 Suppresses B Cell Activation through RelB and Is Regulated by IKKα Phosphorylation. THE JOURNAL OF IMMUNOLOGY 2015; 195:3685-93. [PMID: 26378077 DOI: 10.4049/jimmunol.1500713] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/13/2015] [Indexed: 01/08/2023]
Abstract
Alternative NF-κB signaling is crucial for B cell activation and Ig production, and it is mainly regulated by the inhibitor of κ B kinase (IKK) regulatory complex. Dysregulation of alternative NF-κB signaling in B cells could therefore lead to hyperactive B cells and Ig overproduction. In our previous, study we found that deleted in breast cancer 1 (DBC1) is a suppressor of the alternative NF-κB pathway to attenuate B cell activation. In this study, we report that loss of DBC1 results in spontaneous overproduction of Ig in mice after 10 mo of age. Using a double mutant genetic model, we confirm that DBC1 suppresses B cell activation through RelB inhibition. At the molecular level, we show that DBC1 interacts with alternative NF-κB members RelB and p52 through its leucine zipper domain. In addition, phosphorylation of DBC1 at its C terminus by IKKα facilitates its interaction with RelB and IKKα, indicating that DBC1-mediated suppression of alternative NF-κB is regulated by IKKα. Our results define the molecular mechanism of DBC1 inhibition of alternative NF-κB activation in suppressing B cell activation.
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Affiliation(s)
- Sinyi Kong
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago IL 60611
| | - Hongxin Dong
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago IL 60611
| | - Jianxun Song
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Muthusamy Thiruppathi
- Department of Microbiology and Immunology, University of Illinois College of Medicine Chicago, Chicago, IL 60612
| | - Bellur S Prabhakar
- Department of Microbiology and Immunology, University of Illinois College of Medicine Chicago, Chicago, IL 60612
| | - Quan Qiu
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago IL 60611
| | - Zhenghong Lin
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago IL 60611
| | - Eduardo Chini
- Laboratory of Signal Transduction, Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN 55905; Robert and Arlene Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Bin Zhang
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611; and Division of Hematology/Oncology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Deyu Fang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago IL 60611;
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2080
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McIntyre J, McLenigan MP, Frank EG, Dai X, Yang W, Wang Y, Woodgate R. Posttranslational Regulation of Human DNA Polymerase ι. J Biol Chem 2015; 290:27332-27344. [PMID: 26370087 PMCID: PMC4646365 DOI: 10.1074/jbc.m115.675769] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Indexed: 01/25/2023] Open
Abstract
Human DNA polymerases (pols) η and ι are Y-family DNA polymerase paralogs that facilitate translesion synthesis past damaged DNA. Both polη and polι can be monoubiquitinated in vivo. Polη has been shown to be ubiquitinated at one primary site. When this site is unavailable, three nearby lysines may become ubiquitinated. In contrast, mass spectrometry analysis of monoubiquitinated polι revealed that it is ubiquitinated at over 27 unique sites. Many of these sites are localized in different functional domains of the protein, including the catalytic polymerase domain, the proliferating cell nuclear antigen-interacting region, the Rev1-interacting region, and its ubiquitin binding motifs UBM1 and UBM2. Polι monoubiquitination remains unchanged after cells are exposed to DNA-damaging agents such as UV light (generating UV photoproducts), ethyl methanesulfonate (generating alkylation damage), mitomycin C (generating interstrand cross-links), or potassium bromate (generating direct oxidative DNA damage). However, when exposed to naphthoquinones, such as menadione and plumbagin, which cause indirect oxidative damage through mitochondrial dysfunction, polι becomes transiently polyubiquitinated via Lys11- and Lys48-linked chains of ubiquitin and subsequently targeted for degradation. Polyubiquitination does not occur as a direct result of the perturbation of the redox cycle as no polyubiquitination was observed after treatment with rotenone or antimycin A, which both inhibit mitochondrial electron transport. Interestingly, polyubiquitination was observed after the inhibition of the lysine acetyltransferase KATB3/p300. We hypothesize that the formation of polyubiquitination chains attached to polι occurs via the interplay between lysine acetylation and ubiquitination of ubiquitin itself at Lys11 and Lys48 rather than oxidative damage per se.
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Affiliation(s)
- Justyna McIntyre
- Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371,; Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Mary P McLenigan
- Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371
| | - Ekaterina G Frank
- Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371
| | - Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Roger Woodgate
- Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371,.
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2081
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Mikula M, Rubel T, Karczmarski J, Statkiewicz M, Bomsztyk K, Ostrowski J. Beads-free protein immunoprecipitation for a mass spectrometry-based interactome and posttranslational modifications analysis. Proteome Sci 2015; 13:23. [PMID: 26336360 PMCID: PMC4557753 DOI: 10.1186/s12953-015-0079-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 08/20/2015] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Protein immunoprecipitation (IP) coupled with MS provides means to interrogate protein complexes and their posttranslational modifications (PTMs). In a typical protein IP assay antibodies are conjugated to protein A/G beads requiring large amounts of antibodies, tube transfers and centrifugations. RESULTS As an alternative, we present Matrix-IP, beads-free microplate-based platform with surface-immobilized antibodies. Assay utilizes standard 96-well polypropylene PCR plates that are laboratory-fabricated with UV-C light and then protein A/G coated prior to IP reaction. We demonstrate application of Matrix-IP platform in MS analysis of heterogeneous nuclear ribonucleoprotein K (hnRNP K) interactome and PTMs. CONCLUSION Matrix-IP is time-saving, easy to use high throughput method adaptable for low sample amounts and automation.
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Affiliation(s)
- Michal Mikula
- Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-781 Warsaw, Poland
| | - Tymon Rubel
- Institute of Radioelectronics, Warsaw University of Technology, 00-665 Warsaw, Poland
| | - Jakub Karczmarski
- Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-781 Warsaw, Poland
| | - Malgorzata Statkiewicz
- Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-781 Warsaw, Poland
| | - Karol Bomsztyk
- Department of Medicine, University of Washington, Seattle, 98109 WA USA
| | - Jerzy Ostrowski
- Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, 02-781 Warsaw, Poland ; Department of Gastroenterology, Hepatology and Clinical Oncology, Medical Center for Postgraduate Education, 01-813 Warsaw, Poland
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2082
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Chaudhuri R, Sadrieh A, Hoffman NJ, Parker BL, Humphrey SJ, Stöckli J, Hill AP, James DE, Yang JYH. PhosphOrtholog: a web-based tool for cross-species mapping of orthologous protein post-translational modifications. BMC Genomics 2015; 16:617. [PMID: 26283093 PMCID: PMC4539857 DOI: 10.1186/s12864-015-1820-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/05/2015] [Indexed: 01/27/2023] Open
Abstract
Background Most biological processes are influenced by protein post-translational modifications (PTMs). Identifying novel PTM sites in different organisms, including humans and model organisms, has expedited our understanding of key signal transduction mechanisms. However, with increasing availability of deep, quantitative datasets in diverse species, there is a growing need for tools to facilitate cross-species comparison of PTM data. This is particularly important because functionally important modification sites are more likely to be evolutionarily conserved; yet cross-species comparison of PTMs is difficult since they often lie in structurally disordered protein domains. Current tools that address this can only map known PTMs between species based on known orthologous phosphosites, and do not enable the cross-species mapping of newly identified modification sites. Here, we addressed this by developing a web-based software tool, PhosphOrtholog (www.phosphortholog.com) that accurately maps protein modification sites between different species. This facilitates the comparison of datasets derived from multiple species, and should be a valuable tool for the proteomics community. Results Here we describe PhosphOrtholog, a web-based application for mapping known and novel orthologous PTM sites from experimental data obtained from different species. PhosphOrtholog is the only generic and automated tool that enables cross-species comparison of large-scale PTM datasets without relying on existing PTM databases. This is achieved through pairwise sequence alignment of orthologous protein residues. To demonstrate its utility we apply it to two sets of human and rat muscle phosphoproteomes generated following insulin and exercise stimulation, respectively, and one publicly available mouse phosphoproteome following cellular stress revealing high mapping and coverage efficiency. Although coverage statistics are dataset dependent, PhosphOrtholog increased the number of cross-species mapped sites in all our example data sets by more than double when compared to those recovered using existing resources such as PhosphoSitePlus. Conclusions PhosphOrtholog is the first tool that enables mapping of thousands of novel and known protein phosphorylation sites across species, accessible through an easy-to-use web interface. Identification of conserved PTMs across species from large-scale experimental data increases our knowledgebase of functional PTM sites. Moreover, PhosphOrtholog is generic being applicable to other PTM datasets such as acetylation, ubiquitination and methylation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1820-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rima Chaudhuri
- Charles Perkins Centre, School of Molecular Biosciences, University of Sydney, Camperdown, NSW, 2006, Australia. .,Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| | - Arash Sadrieh
- Lowy Packer Building, Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia.
| | - Nolan J Hoffman
- Charles Perkins Centre, School of Molecular Biosciences, University of Sydney, Camperdown, NSW, 2006, Australia. .,Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| | - Benjamin L Parker
- Charles Perkins Centre, School of Molecular Biosciences, University of Sydney, Camperdown, NSW, 2006, Australia. .,Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| | - Sean J Humphrey
- Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, Martinsried, Germany.
| | - Jacqueline Stöckli
- Charles Perkins Centre, School of Molecular Biosciences, University of Sydney, Camperdown, NSW, 2006, Australia. .,Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| | - Adam P Hill
- Lowy Packer Building, Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia.
| | - David E James
- Charles Perkins Centre, School of Molecular Biosciences, University of Sydney, Camperdown, NSW, 2006, Australia. .,Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
| | - Jean Yee Hwa Yang
- School of Mathematics and Statistics, University of Sydney, Camperdown, NSW, 2006, Australia.
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2083
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Samejima K, Platani M, Wolny M, Ogawa H, Vargiu G, Knight PJ, Peckham M, Earnshaw WC. The Inner Centromere Protein (INCENP) Coil Is a Single α-Helix (SAH) Domain That Binds Directly to Microtubules and Is Important for Chromosome Passenger Complex (CPC) Localization and Function in Mitosis. J Biol Chem 2015; 290:21460-72. [PMID: 26175154 PMCID: PMC4571873 DOI: 10.1074/jbc.m115.645317] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Indexed: 11/06/2022] Open
Abstract
The chromosome passenger complex (CPC) is a master regulator of mitosis. Inner centromere protein (INCENP) acts as a scaffold regulating CPC localization and activity. During early mitosis, the N-terminal region of INCENP forms a three-helix bundle with Survivin and Borealin, directing the CPC to the inner centromere where it plays essential roles in chromosome alignment and the spindle assembly checkpoint. The C-terminal IN box region of INCENP is responsible for binding and activating Aurora B kinase. The central region of INCENP has been proposed to comprise a coiled coil domain acting as a spacer between the N- and C-terminal domains that is involved in microtubule binding and regulation of the spindle checkpoint. Here we show that the central region (213 residues) of chicken INCENP is not a coiled coil but a ∼ 32-nm-long single α-helix (SAH) domain. The N-terminal half of this domain directly binds to microtubules in vitro. By analogy with previous studies of myosin 10, our data suggest that the INCENP SAH might stretch up to ∼ 80 nm under physiological forces. Thus, the INCENP SAH could act as a flexible "dog leash," allowing Aurora B to phosphorylate dynamic substrates localized in the outer kinetochore while at the same time being stably anchored to the heterochromatin of the inner centromere. Furthermore, by achieving this flexibility via an SAH domain, the CPC avoids a need for dimerization (required for coiled coil formation), which would greatly complicate regulation of the proximity-induced trans-phosphorylation that is critical for Aurora B activation.
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Affiliation(s)
- Kumiko Samejima
- From The Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom and
| | - Melpomeni Platani
- From The Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom and
| | - Marcin Wolny
- The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Hiromi Ogawa
- From The Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom and
| | - Giulia Vargiu
- From The Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom and
| | - Peter J Knight
- The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Michelle Peckham
- The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - William C Earnshaw
- From The Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, United Kingdom and
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2084
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Williams GR, Bethard JR, Berkaw MN, Nagel AK, Luttrell LM, Ball LE. Exploring G protein-coupled receptor signaling networks using SILAC-based phosphoproteomics. Methods 2015; 92:36-50. [PMID: 26160508 DOI: 10.1016/j.ymeth.2015.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 12/21/2022] Open
Abstract
The type 1 parathyroid hormone receptor (PTH1R) is a key regulator of calcium homeostasis and bone turnover. Here, we employed SILAC-based quantitative mass spectrometry and bioinformatic pathways analysis to examine global changes in protein phosphorylation following short-term stimulation of endogenously expressed PTH1R in osteoblastic cells in vitro. Following 5min exposure to the conventional agonist, PTH(1-34), we detected significant changes in the phosphorylation of 224 distinct proteins. Kinase substrate motif enrichment demonstrated that consensus motifs for PKA and CAMK2 were the most heavily upregulated within the phosphoproteome, while consensus motifs for mitogen-activated protein kinases were strongly downregulated. Signaling pathways analysis identified ERK1/2 and AKT as important nodal kinases in the downstream network and revealed strong regulation of small GTPases involved in cytoskeletal rearrangement, cell motility, and focal adhesion complex signaling. Our data illustrate the utility of quantitative mass spectrometry in measuring dynamic changes in protein phosphorylation following GPCR activation.
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Affiliation(s)
- Grace R Williams
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jennifer R Bethard
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Mary N Berkaw
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Alexis K Nagel
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Louis M Luttrell
- Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Lauren E Ball
- Department of Molecular and Cellular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA.
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2085
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Pagel O, Loroch S, Sickmann A, Zahedi RP. Current strategies and findings in clinically relevant post-translational modification-specific proteomics. Expert Rev Proteomics 2015; 12:235-53. [PMID: 25955281 PMCID: PMC4487610 DOI: 10.1586/14789450.2015.1042867] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mass spectrometry-based proteomics has considerably extended our knowledge about the occurrence and dynamics of protein post-translational modifications (PTMs). So far, quantitative proteomics has been mainly used to study PTM regulation in cell culture models, providing new insights into the role of aberrant PTM patterns in human disease. However, continuous technological and methodical developments have paved the way for an increasing number of PTM-specific proteomic studies using clinical samples, often limited in sample amount. Thus, quantitative proteomics holds a great potential to discover, validate and accurately quantify biomarkers in body fluids and primary tissues. A major effort will be to improve the complete integration of robust but sensitive proteomics technology to clinical environments. Here, we discuss PTMs that are relevant for clinical research, with a focus on phosphorylation, glycosylation and proteolytic cleavage; furthermore, we give an overview on the current developments and novel findings in mass spectrometry-based PTM research.
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Affiliation(s)
- Oliver Pagel
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Straße 6b, 44227 Dortmund, Germany
| | - Stefan Loroch
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Straße 6b, 44227 Dortmund, Germany
| | | | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Otto-Hahn-Straße 6b, 44227 Dortmund, Germany
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2086
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López Villar E, Madero L, A López-Pascual J, C Cho W. Study of phosphorylation events for cancer diagnoses and treatment. Clin Transl Med 2015; 4:59. [PMID: 26055493 PMCID: PMC4460185 DOI: 10.1186/s40169-015-0059-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 05/19/2015] [Indexed: 02/07/2023] Open
Abstract
The activation of signaling cascades in response to extracellular and intracellular stimuli to control cell growth, proliferation and survival, is orchestrated by protein kinases via phosphorylation. A critical issue is the study of the mechanisms of cancer cells for the development of more effective drugs. With the application of the new proteomic technologies, together with the advancement in the sequencing of the human proteome, patients will therefore be benefited by the discovery of novel therapeutic and/or diagnostic protein targets. Furthermore, the advances in proteomic approaches and the Human Proteome Organization (HUPO) have opened a new door which is helpful in the identification of patients at risk and towards improving current therapies. Modification of the signaling-networks via mutations or abnormal protein expression underlies the cause or consequence of many diseases including cancer. Resulting data is used to reveal connections between genes proteins and compounds and the related molecular pathways for underlining disease states. As a delegate of HUPO, for human proteome on children assays and studies, we, at Hospital Universitario Niño Jesús, are seeking to support the human proteome in this context. Clinical goals have to be clearly established and proteomics experts have to set up the appropriate proteomic strategy, which coupled to bioinformatics will make it possible to achieve new therapies for patients with poor prognosis. We envision to combine our up-coming data to the HUPO organization in order to support international efforts to advance the cure of cancer disease.
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Affiliation(s)
- Elena López Villar
- Oncohematology of Children Department, Hospital Universitario Infantil Niño Jesús, Av. Menéndez Pelayo 65, Madrid, Spain,
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2087
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Effect of sialylation on EGFR phosphorylation and resistance to tyrosine kinase inhibition. Proc Natl Acad Sci U S A 2015; 112:6955-60. [PMID: 25971727 DOI: 10.1073/pnas.1507329112] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Epidermal growth factor receptor (EGFR) is a heavily glycosylated transmembrane receptor tyrosine kinase. Upon EGF-binding, EGFR undergoes conformational changes to dimerize, resulting in kinase activation and autophosphorylation and downstream signaling. Tyrosine kinase inhibitors (TKIs) have been used to treat lung cancer by inhibiting EGFR phosphorylation. Previously, we demonstrated that EGFR sialylation suppresses its dimerization and phosphorylation. In this report, we further investigated the effect of sialylation on the phosphorylation profile of EGFR in TKI-sensitive and TKI-resistant cells. Sialylation was induced in cancer progression to inhibit the association of EGFR with EGF and the subsequent autophosphorylation. In the absence of EGF the TKI-resistant EGFR mutant (L858R/T790M) had a higher degree of sialylation and phosphorylation at Y1068, Y1086, and Y1173 than the TKI-sensitive EGFR. In addition, although sialylation in the TKI-resistant mutants suppresses EGFR tyrosine phosphorylation, with the most significant effect on the Y1173 site, the sialylation effect is not strong enough to stop cancer progression by inhibiting the phosphorylation of these three sites. These findings were supported further by the observation that the L858R/T790M EGFR mutant, when treated with sialidase or sialyltransferase inhibitor, showed an increase in tyrosine phosphorylation, and the sensitivity of the corresponding resistant lung cancer cells to gefitinib was reduced by desialylation and was enhanced by sialylation.
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2088
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Petsalaki E, Helbig AO, Gopal A, Pasculescu A, Roth FP, Pawson T. SELPHI: correlation-based identification of kinase-associated networks from global phospho-proteomics data sets. Nucleic Acids Res 2015; 43:W276-82. [PMID: 25948583 PMCID: PMC4489257 DOI: 10.1093/nar/gkv459] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/27/2015] [Indexed: 12/13/2022] Open
Abstract
While phospho-proteomics studies have shed light on the dynamics of cellular signaling, they mainly describe global effects and rarely explore mechanistic details, such as kinase/substrate relationships. Tools and databases, such as NetworKIN and PhosphoSitePlus, provide valuable regulatory details on signaling networks but rely on prior knowledge. They therefore provide limited information on less studied kinases and fewer unexpected relationships given that better studied signaling events can mask condition- or cell-specific ‘network wiring’. SELPHI is a web-based tool providing in-depth analysis of phospho-proteomics data that is intuitive and accessible to non-bioinformatics experts. It uses correlation analysis of phospho-sites to extract kinase/phosphatase and phospho-peptide associations, and highlights the potential flow of signaling in the system under study. We illustrate SELPHI via analysis of phospho-proteomics data acquired in the presence of erlotinib—a tyrosine kinase inhibitor (TKI)—in cancer cells expressing TKI-resistant and -sensitive variants of the Epidermal Growth Factor Receptor. In this data set, SELPHI revealed information overlooked by the reporting study, including the known role of MET and EPHA2 kinases in conferring resistance to erlotinib in TKI sensitive strains. SELPHI can significantly enhance the analysis of phospho-proteomics data contributing to improved understanding of sample-specific signaling networks. SELPHI is freely available via http://llama.mshri.on.ca/SELPHI.
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Affiliation(s)
- Evangelia Petsalaki
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada
| | - Andreas O Helbig
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, M5G 1X5, Canada
| | - Anjali Gopal
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada
| | - Adrian Pasculescu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada
| | - Frederick P Roth
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada Donnelly Centre and Departments of Molecular Genetics and Computer Science, University of Toronto, Toronto, Ontario, M5G 1X8, Canada Center for Cancer Systems Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, 02215, USA Canadian Institute for Advanced Research, Toronto, Ontario, M5G 1Z8, Canada
| | - Tony Pawson
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X8, Canada
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2089
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Gonzalez Herrera KN, Lee J, Haigis MC. Intersections between mitochondrial sirtuin signaling and tumor cell metabolism. Crit Rev Biochem Mol Biol 2015; 50:242-55. [PMID: 25898275 DOI: 10.3109/10409238.2015.1031879] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cancer cells use glucose and glutamine to facilitate cell growth and proliferation, a process coined "metabolic reprograming" - an emerging hallmark of cancer. Inside the cell, these nutrients synergize to produce metabolic building blocks, such as nucleic acids, lipids and proteins, as well as energy (ATP), glutathione and reducing equivalents (NADPH), required for survival, growth and proliferation. Intense research aimed at understanding the underlying cause of the metabolic rewiring has revealed that established oncogenes and tumor suppressors involved in signaling alter cellular metabolism to contribute to the transition from a normal quiescent cell to a rapidly proliferating cancer cell. Likewise, bona fide metabolic sensors are emerging as regulators of tumorigenesis. This review will focus on one such family of sensors, sirtuins, which utilize NAD(+) as a cofactor to catalyze deacetylation, deacylation and ADP-ribosylation of their protein substrates. In this review, we will enumerate how cancer cell metabolism is different from a normal quiescent cell and highlight the emerging role of mitochondrial sirtuin signaling in the regulation of tumor metabolism.
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2090
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Palacios-Moreno J, Foltz L, Guo A, Stokes MP, Kuehn ED, George L, Comb M, Grimes ML. Neuroblastoma tyrosine kinase signaling networks involve FYN and LYN in endosomes and lipid rafts. PLoS Comput Biol 2015; 11:e1004130. [PMID: 25884760 PMCID: PMC4401789 DOI: 10.1371/journal.pcbi.1004130] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 01/14/2015] [Indexed: 12/16/2022] Open
Abstract
Protein phosphorylation plays a central role in creating a highly dynamic network of interacting proteins that reads and responds to signals from growth factors in the cellular microenvironment. Cells of the neural crest employ multiple signaling mechanisms to control migration and differentiation during development. It is known that defects in these mechanisms cause neuroblastoma, but how multiple signaling pathways interact to govern cell behavior is unknown. In a phosphoproteomic study of neuroblastoma cell lines and cell fractions, including endosomes and detergent-resistant membranes, 1622 phosphorylated proteins were detected, including more than half of the receptor tyrosine kinases in the human genome. Data were analyzed using a combination of graph theory and pattern recognition techniques that resolve data structure into networks that incorporate statistical relationships and protein-protein interaction data. Clusters of proteins in these networks are indicative of functional signaling pathways. The analysis indicates that receptor tyrosine kinases are functionally compartmentalized into distinct collaborative groups distinguished by activation and intracellular localization of SRC-family kinases, especially FYN and LYN. Changes in intracellular localization of activated FYN and LYN were observed in response to stimulation of the receptor tyrosine kinases, ALK and KIT. The results suggest a mechanism to distinguish signaling responses to activation of different receptors, or combinations of receptors, that govern the behavior of the neural crest, which gives rise to neuroblastoma. Neuroblastoma is a childhood cancer for which therapeutic progress has been slow. We analyzed a large number phosphorylated proteins in neuroblastoma cells to discern patterns that indicate functional signal transduction pathways. To analyze the data, we developed novel techniques that resolve data structure and visualize that structure as networks that represent both protein interactions and statistical relationships. We also fractionated neuroblastoma cells to examine the location of signaling proteins in different membrane fractions and organelles. The analysis revealed that signaling pathways are functionally and physically compartmentalized into distinct collaborative groups distinguished by phosphorylation patterns and intracellular localization. We found that two related proteins (FYN and LYN) act like central hubs in the tyrosine kinase signaling network that change intracellular localization and activity in response to activation of different receptors.
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Affiliation(s)
- Juan Palacios-Moreno
- Division of Biological Sciences, Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America
| | - Lauren Foltz
- Division of Biological Sciences, Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America
| | - Ailan Guo
- Cell Signaling Technology, Inc., Danvers, Massachusetts, United States of America
| | - Matthew P. Stokes
- Cell Signaling Technology, Inc., Danvers, Massachusetts, United States of America
| | - Emily D. Kuehn
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Lynn George
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, Montana, United States of America
| | - Michael Comb
- Cell Signaling Technology, Inc., Danvers, Massachusetts, United States of America
| | - Mark L. Grimes
- Division of Biological Sciences, Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America
- * E-mail:
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2091
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Ha BH, Morse EM, Turk BE, Boggon TJ. Signaling, Regulation, and Specificity of the Type II p21-activated Kinases. J Biol Chem 2015; 290:12975-83. [PMID: 25855792 DOI: 10.1074/jbc.r115.650416] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The p21-activated kinases (PAKs) are a family of six serine/threonine kinases that act as key effectors of RHO family GTPases in mammalian cells. PAKs are subdivided into two groups: type I PAKs (PAK1, PAK2, and PAK3) and type II PAKs (PAK4, PAK5, and PAK6). Although these groups are involved in common signaling pathways, recent work indicates that the two groups have distinct modes of regulation and have both unique and common substrates. Here, we review recent insights into the molecular level details that govern regulation of type II PAK signaling. We also consider mechanisms by which signal transduction is regulated at the level of substrate specificity. Finally, we discuss the implications of these studies for clinical targeting of these kinases.
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Affiliation(s)
| | - Elizabeth M Morse
- Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520
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