1
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McIvor JAP, Larsen DS, Mercadante D. Charge Relaying within a Phospho-Motif Rescue Binding Competency of a Disordered Transcription Factor. J Chem Inf Model 2024; 64:6041-6052. [PMID: 39074869 DOI: 10.1021/acs.jcim.4c00286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Structural disorder in proteins is central to cellular signaling, where conformational plasticity equips molecules to promiscuously interact with different partners. By engaging with multiple binding partners via the rearrangement of its three helices, the nuclear coactivator binding domain (NCBD) of the CBP/p300 transcription factor is a paradigmatic example of promiscuity. Recently, molecular simulations and experiments revealed that, through the establishment of long-range electrostatic interactions, intended as salt-bridges formed between the post-translationally inserted phosphate and positively charged residues in helix H3 of NCBD, phosphorylation triggers NCBD compaction, lowering its affinity for binding partners. By means of extensive molecular simulations, we here investigated the effect of short-range electrostatics on the conformational ensemble of NCBD, by monitoring the interactions between a phosphorylated serine and conserved positively charged residues within the NCBD phospho-motif. We found that empowering proximal electrostatic interactions, as opposed to long-range electrostatics, can reshape the NCBD ensemble rescuing the binding competency of phosphorylated NCBD. Given the conservation of positive charges in phospho-motifs, proximal electrostatic interactions might dampen the effects of phosphorylation and act as a relay to regulate phosphorylated intrinsically disordered proteins, ultimately tuning the binding affinity for different cellular partners.
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Affiliation(s)
- Jordan A P McIvor
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Danaé S Larsen
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
| | - Davide Mercadante
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand
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2
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Oh JW, Beer MA. Gapped-kmer sequence modeling robustly identifies regulatory vocabularies and distal enhancers conserved between evolutionarily distant mammals. Nat Commun 2024; 15:6464. [PMID: 39085231 PMCID: PMC11291912 DOI: 10.1038/s41467-024-50708-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 07/17/2024] [Indexed: 08/02/2024] Open
Abstract
Gene regulatory elements drive complex biological phenomena and their mutations are associated with common human diseases. The impacts of human regulatory variants are often tested using model organisms such as mice. However, mapping human enhancers to conserved elements in mice remains a challenge, due to both rapid enhancer evolution and limitations of current computational methods. We analyze distal enhancers across 45 matched human/mouse cell/tissue pairs from a comprehensive dataset of DNase-seq experiments, and show that while cell-specific regulatory vocabulary is conserved, enhancers evolve more rapidly than promoters and CTCF binding sites. Enhancer conservation rates vary across cell types, in part explainable by tissue specific transposable element activity. We present an improved genome alignment algorithm using gapped-kmer features, called gkm-align, and make genome wide predictions for 1,401,803 orthologous regulatory elements. We show that gkm-align discovers 23,660 novel human/mouse conserved enhancers missed by previous algorithms, with strong evidence of conserved functional activity.
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Affiliation(s)
- Jin Woo Oh
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Michael A Beer
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA.
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3
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Razavi-Mohseni M, Huang W, Guo YA, Shigaki D, Ho SWT, Tan P, Skanderup AJ, Beer MA. Machine learning identifies activation of RUNX/AP-1 as drivers of mesenchymal and fibrotic regulatory programs in gastric cancer. Genome Res 2024; 34:680-695. [PMID: 38777607 PMCID: PMC11216402 DOI: 10.1101/gr.278565.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 05/13/2024] [Indexed: 05/25/2024]
Abstract
Gastric cancer (GC) is the fifth most common cancer worldwide and is a heterogeneous disease. Among GC subtypes, the mesenchymal phenotype (Mes-like) is more invasive than the epithelial phenotype (Epi-like). Although gene expression of the epithelial-to-mesenchymal transition (EMT) has been studied, the regulatory landscape shaping this process is not fully understood. Here we use ATAC-seq and RNA-seq data from a compendium of GC cell lines and primary tumors to detect drivers of regulatory state changes and their transcriptional responses. Using the ATAC-seq data, we developed a machine learning approach to determine the transcription factors (TFs) regulating the subtypes of GC. We identified TFs driving the mesenchymal (RUNX2, ZEB1, SNAI2, AP-1 dimer) and the epithelial (GATA4, GATA6, KLF5, HNF4A, FOXA2, GRHL2) states in GC. We identified DNA copy number alterations associated with dysregulation of these TFs, specifically deletion of GATA4 and amplification of MAPK9 Comparisons with bulk and single-cell RNA-seq data sets identified activation toward fibroblast-like epigenomic and expression signatures in Mes-like GC. The activation of this mesenchymal fibrotic program is associated with differentially accessible DNA cis-regulatory elements flanking upregulated mesenchymal genes. These findings establish a map of TF activity in GC and highlight the role of copy number driven alterations in shaping epigenomic regulatory programs as potential drivers of GC heterogeneity and progression.
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Affiliation(s)
- Milad Razavi-Mohseni
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Weitai Huang
- Laboratory of Computational Cancer Genomics, Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore 138672
| | - Yu A Guo
- Laboratory of Computational Cancer Genomics, Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore 138672
| | - Dustin Shigaki
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Shamaine Wei Ting Ho
- Laboratory of Cancer Epigenetic Regulation, Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore 138672
| | - Patrick Tan
- Laboratory of Cancer Epigenetic Regulation, Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore 138672
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore 169857
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593
| | - Anders J Skanderup
- Laboratory of Computational Cancer Genomics, Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore 138672
| | - Michael A Beer
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA;
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4
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Wang M, Wang D, Zhang K, Ngo V, Fan S, Wang W. Motto: Representing Motifs in Consensus Sequences with Minimum Information Loss. Genetics 2020; 216:353-358. [PMID: 32816922 PMCID: PMC7536857 DOI: 10.1534/genetics.120.303597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/17/2020] [Indexed: 11/21/2022] Open
Abstract
Sequence analysis frequently requires intuitive understanding and convenient representation of motifs. Typically, motifs are represented as position weight matrices (PWMs) and visualized using sequence logos. However, in many scenarios, in order to interpret the motif information or search for motif matches, it is compact and sufficient to represent motifs by wildcard-style consensus sequences (such as [GC][AT]GATAAG[GAC]). Based on mutual information theory and Jensen-Shannon divergence, we propose a mathematical framework to minimize the information loss in converting PWMs to consensus sequences. We name this representation as sequence Motto and have implemented an efficient algorithm with flexible options for converting motif PWMs into Motto from nucleotides, amino acids, and customized characters. We show that this representation provides a simple and efficient way to identify the binding sites of 1156 common transcription factors (TFs) in the human genome. The effectiveness of the method was benchmarked by comparing sequence matches found by Motto with PWM scanning results found by FIMO. On average, our method achieves a 0.81 area under the precision-recall curve, significantly (P-value < 0.01) outperforming all existing methods, including maximal positional weight, Cavener's method, and minimal mean square error. We believe this representation provides a distilled summary of a motif, as well as the statistical justification.
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Affiliation(s)
- Mengchi Wang
- Bioinformatics and Systems Biology, University of California at San Diego, La Jolla, California 92093
| | - David Wang
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093
| | - Kai Zhang
- Bioinformatics and Systems Biology, University of California at San Diego, La Jolla, California 92093
| | - Vu Ngo
- Bioinformatics and Systems Biology, University of California at San Diego, La Jolla, California 92093
| | - Shicai Fan
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093
- School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, China 610054
| | - Wei Wang
- Bioinformatics and Systems Biology, University of California at San Diego, La Jolla, California 92093
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
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5
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Vora SM, Fassler JS, Phillips BT. Centrosomes are required for proper β-catenin processing and Wnt response. Mol Biol Cell 2020; 31:1951-1961. [PMID: 32583737 PMCID: PMC7525817 DOI: 10.1091/mbc.e20-02-0139] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The Wnt/β-catenin signaling pathway is central to metazoan development and routinely dysregulated in cancer. Wnt/β-catenin signaling initiates transcriptional reprogramming upon stabilization of the transcription factor β-catenin, which is otherwise posttranslationally processed by a destruction complex and degraded by the proteasome. Since various Wnt signaling components are enriched at centrosomes, we examined the functional contribution of centrosomes to Wnt signaling, β-catenin regulation, and posttranslational modifications. In HEK293 cells depleted of centrosomes we find that β-catenin synthesis and degradation rates are unaffected but that the normal accumulation of β-catenin in response to Wnt signaling is attenuated. This is due to accumulation of a novel high-molecular-weight form of phosphorylated β-catenin that is constitutively degraded in the absence of Wnt. Wnt signaling operates by inhibiting the destruction complex and thereby reducing destruction complex–phosphorylated β-catenin, but high-molecular-weight β-catenin is unexpectedly increased by Wnt signaling. Therefore these studies have identified a pool of β-catenin effectively shielded from regulation by Wnt. We present a model whereby centrosomes prevent inappropriate β-catenin modifications that antagonize normal stabilization by Wnt signals.
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Affiliation(s)
- Setu M Vora
- Department of Biology, University of Iowa, Iowa City, IA 52242-1324
| | - Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242-1324
| | - Bryan T Phillips
- Department of Biology, University of Iowa, Iowa City, IA 52242-1324
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6
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Krab LC, Marcos-Alcalde I, Assaf M, Balasubramanian M, Andersen JB, Bisgaard AM, Fitzpatrick DR, Gudmundsson S, Huisman SA, Kalayci T, Maas SM, Martinez F, McKee S, Menke LA, Mulder PA, Murch OD, Parker M, Pie J, Ramos FJ, Rieubland C, Rosenfeld Mokry JA, Scarano E, Shinawi M, Gómez-Puertas P, Tümer Z, Hennekam RC. Delineation of phenotypes and genotypes related to cohesin structural protein RAD21. Hum Genet 2020; 139:575-592. [PMID: 32193685 PMCID: PMC7170815 DOI: 10.1007/s00439-020-02138-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/10/2020] [Indexed: 01/23/2023]
Abstract
RAD21 encodes a key component of the cohesin complex, and variants in RAD21 have been associated with Cornelia de Lange Syndrome (CdLS). Limited information on phenotypes attributable to RAD21 variants and genotype–phenotype relationships is currently published. We gathered a series of 49 individuals from 33 families with RAD21 alterations [24 different intragenic sequence variants (2 recurrent), 7 unique microdeletions], including 24 hitherto unpublished cases. We evaluated consequences of 12 intragenic variants by protein modelling and molecular dynamic studies. Full clinical information was available for 29 individuals. Their phenotype is an attenuated CdLS phenotype compared to that caused by variants in NIPBL or SMC1A for facial morphology, limb anomalies, and especially for cognition and behavior. In the 20 individuals with limited clinical information, additional phenotypes include Mungan syndrome (in patients with biallelic variants) and holoprosencephaly, with or without CdLS characteristics. We describe several additional cases with phenotypes including sclerocornea, in which involvement of the RAD21 variant is uncertain. Variants were frequently familial, and genotype–phenotype analyses demonstrated striking interfamilial and intrafamilial variability. Careful phenotyping is essential in interpreting consequences of RAD21 variants, and protein modeling and dynamics can be helpful in determining pathogenicity. The current study should be helpful when counseling families with a RAD21 variation.
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Affiliation(s)
- Lianne C Krab
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands. .,Cordaan, Outpatient Clinic for ID Medicine, Klinkerweg 75, 1033 PK, Amsterdam, The Netherlands. .,Odion, Outpatient Clinic for ID Medicine, Purmerend, The Netherlands.
| | - Iñigo Marcos-Alcalde
- Molecular Modelling Group, Centro de Biología Molecular Severo Ochoa, CBMSO (CSIC-UAM), Madrid, Spain.,School of Experimental Sciences-IIB, Universidad Francisco de Vitoria, UFV, Pozuelo de Alarcón, Spain
| | - Melissa Assaf
- Banner Childrens Specialists Neurology Clinic, Glendale, AZ, USA
| | - Meena Balasubramanian
- Clinical Genetics Service, Sheffield Children's Hospital, Academic Unit for Child Health, University of Sheffield, Sheffield, UK
| | - Janne Bayer Andersen
- Department of Clinical Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, 2600, Glostrup, Denmark
| | - Anne-Marie Bisgaard
- Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
| | | | - Sanna Gudmundsson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Sylvia A Huisman
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.,Prinsenstichting, Purmerend, The Netherlands
| | - Tugba Kalayci
- Division of Medical Genetics, Department of Internal Medicine, Istanbul University, Istanbul, Turkey
| | - Saskia M Maas
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.,Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Francisco Martinez
- Unidad de Genética, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Shane McKee
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Leonie A Menke
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands
| | - Paul A Mulder
- Autism Team Northern-Netherlands, Jonx Department of Youth Mental Health and Autism, Lentis Psychiatric Institute, Groningen, The Netherlands
| | - Oliver D Murch
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
| | - Michael Parker
- Clinical Genetic Service, Northern General Hospital, Sheffield, UK
| | - Juan Pie
- Unit of Clinical Genetics Unit, Service of Pediatrics, University Hospital "Lozano Blesa", University of Zaragoza School of Medicine, Saragossa, Spain
| | - Feliciano J Ramos
- Unit of Clinical Genetics Unit and Functional Genomics, Department of Pharmacology and Physiology, University of Zaragoza School of Medicine, Saragossa, Spain
| | - Claudine Rieubland
- Department of Pediatrics, Division of Human Genetics, Inselspital, University of Bern, Bern, Switzerland
| | - Jill A Rosenfeld Mokry
- Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor Genetics Laboratories, Houston, TX, USA
| | - Emanuela Scarano
- Rare Disease Unit, Department of Pediatrics, St. Orsola Hospital, Bologna, Italy
| | - Marwan Shinawi
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Paulino Gómez-Puertas
- Molecular Modelling Group, Centro de Biología Molecular Severo Ochoa, CBMSO (CSIC-UAM), Madrid, Spain
| | - Zeynep Tümer
- Department of Clinical Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, 2600, Glostrup, Denmark. .,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Raoul C Hennekam
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
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7
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Gratz R, Brumbarova T, Ivanov R, Trofimov K, Tünnermann L, Ochoa-Fernandez R, Blomeier T, Meiser J, Weidtkamp-Peters S, Zurbriggen MD, Bauer P. Phospho-mutant activity assays provide evidence for alternative phospho-regulation pathways of the transcription factor FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR. THE NEW PHYTOLOGIST 2020; 225:250-267. [PMID: 31487399 PMCID: PMC6916400 DOI: 10.1111/nph.16168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/16/2019] [Indexed: 05/03/2023]
Abstract
The key basic helix-loop-helix (bHLH) transcription factor in iron (Fe) uptake, FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT), is controlled by multiple signaling pathways, important to adjust Fe acquisition to growth and environmental constraints. FIT protein exists in active and inactive protein pools, and phosphorylation of serine Ser272 in the C-terminus, a regulatory domain of FIT, provides a trigger for FIT activation. Here, we use phospho-mutant activity assays and study phospho-mimicking and phospho-dead mutations of three additional predicted phosphorylation sites, namely at Ser221 and at tyrosines Tyr238 and Tyr278, besides Ser 272. Phospho-mutations at these sites affect FIT activities in yeast, plant, and mammalian cells. The diverse array of cellular phenotypes is seen at the level of cellular localization, nuclear mobility, homodimerization, and dimerization with the FIT-activating partner bHLH039, promoter transactivation, and protein stability. Phospho-mimicking Tyr mutations of FIT disturb fit mutant plant complementation. Taken together, we provide evidence that FIT is activated through Ser and deactivated through Tyr site phosphorylation. We therefore propose that FIT activity is regulated by alternative phosphorylation pathways.
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Affiliation(s)
- Regina Gratz
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Tzvetina Brumbarova
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
| | - Ksenia Trofimov
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Laura Tünnermann
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Rocio Ochoa-Fernandez
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Tim Blomeier
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Johannes Meiser
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
- Department of Oncology, Luxembourg Institute of Health, 1445, Strassen, Luxembourg
| | | | - Matias D Zurbriggen
- Institute of Synthetic Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biosciences-Plant Biology, Saarland University, 66123, Saarbruecken, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, 40225, Düsseldorf, Germany
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8
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Hombach-Barrigah A, Bartsch K, Smirlis D, Rosenqvist H, MacDonald A, Dingli F, Loew D, Späth GF, Rachidi N, Wiese M, Clos J. Leishmania donovani 90 kD Heat Shock Protein - Impact of Phosphosites on Parasite Fitness, Infectivity and Casein Kinase Affinity. Sci Rep 2019; 9:5074. [PMID: 30911045 PMCID: PMC6434042 DOI: 10.1038/s41598-019-41640-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/11/2019] [Indexed: 12/28/2022] Open
Abstract
Leishmania parasites are thought to control protein activity at the post-translational level, e.g. by protein phosphorylation. In the pathogenic amastigote, the mammalian stage of Leishmania parasites, heat shock proteins show increased phosphorylation, indicating a role in stage-specific signal transduction. Here we investigate the impact of phosphosites in the L. donovani heat shock protein 90. Using a chemical knock-down/genetic complementation approach, we mutated 11 confirmed or presumed phosphorylation sites and assessed the impact on overall fitness, morphology and in vitro infectivity. Most phosphosite mutations affected the growth and morphology of promastigotes in vitro, but with one exception, none of the phosphorylation site mutants had a selective impact on the in vitro infection of macrophages. Surprisingly, aspartate replacements mimicking the negative charge of phosphorylated serines or threonines had mostly negative impacts on viability and infectivity. HSP90 is a substrate for casein kinase 1.2-catalysed phosphorylation in vitro. While several putative phosphosite mutations abrogated casein kinase 1.2 activity on HSP90, only Ser289 could be identified as casein kinase target by mass spectrometry. In summary, our data show HSP90 as a downstream client of phosphorylation-mediated signalling in an organism that depends on post-transcriptional gene regulation.
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Affiliation(s)
| | | | - Despina Smirlis
- Institut Pasteur and Institut National de Santé et Recherche Médicale INSERM U1201, Unité de Parasitologie Moléculaire et Signalisation, Paris, France
- Hellenic Pasteur Institute, Athens, Greece
| | - Heidi Rosenqvist
- Strathclyde Institute of Pharmacy and Biomedical Sciences (SIPBS) University of Strathclyde, Glasgow, Scotland, UK
- Novo Nordisk A/S, Gentofte, Denmark
| | - Andrea MacDonald
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Florent Dingli
- Laboratoire de Spectrométrie de Masse Protéomique, Centre de Recherche, Institut Curie, PSL Research University, Paris, France
| | - Damarys Loew
- Laboratoire de Spectrométrie de Masse Protéomique, Centre de Recherche, Institut Curie, PSL Research University, Paris, France
| | - Gerald F Späth
- Institut Pasteur and Institut National de Santé et Recherche Médicale INSERM U1201, Unité de Parasitologie Moléculaire et Signalisation, Paris, France
| | - Najma Rachidi
- Institut Pasteur and Institut National de Santé et Recherche Médicale INSERM U1201, Unité de Parasitologie Moléculaire et Signalisation, Paris, France
| | - Martin Wiese
- Strathclyde Institute of Pharmacy and Biomedical Sciences (SIPBS) University of Strathclyde, Glasgow, Scotland, UK
| | - Joachim Clos
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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9
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Pancha I, Shima H, Higashitani N, Igarashi K, Higashitani A, Tanaka K, Imamura S. Target of rapamycin-signaling modulates starch accumulation via glycogenin phosphorylation status in the unicellular red alga Cyanidioschyzon merolae. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:485-499. [PMID: 30351485 DOI: 10.1111/tpj.14136] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/23/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
The target of rapamycin (TOR) signaling pathway is involved in starch accumulation in various eukaryotic organisms; however, the molecular mechanism behind this phenomenon in eukaryotes has not been elucidated. We report a regulatory mechanism of starch accumulation by TOR in the unicellular red alga, Cyanidioschyzon merolae. The starch content in C. merolae after TOR-inactivation by rapamycin, a TOR-specific inhibitor, was increased by approximately 10-fold in comparison with its drug vehicle, dimethyl sulfoxide. However, our previous transcriptome analysis showed that the expression level of genes related to carbohydrate metabolism was unaffected by rapamycin, indicating that starch accumulation is regulated at post-transcriptional levels. In this study, we performed a phosphoproteome analysis using liquid chromatography-tandem mass spectrometry to investigate potential post-transcriptional modifications, and identified 52 proteins as candidate TOR substrates. Among the possible substrates, we focused on the function of CmGLG1, because its phosphorylation at the Ser613 residue was decreased after rapamycin treatment, and overexpression of CmGLG1 resulted in a 4.7-fold higher starch content. CmGLG1 is similar to the priming protein, glycogenin, which is required for the initiation of starch/glycogen synthesis, and a budding yeast complementation assay demonstrated that CmGLG1 can functionally substitute for glycogenin. We found an approximately 60% reduction in the starch content in a phospho-mimicking CmGLG1 overexpression strain, in which Ser613 was substituted with aspartic acid, in comparison with the wild-type CmGLG1 overexpression cells. Our results indicate that TOR modulates starch accumulation by changing the phosphorylation status of the CmGLG1 Ser613 residue in C. merolae.
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Affiliation(s)
- Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Hiroki Shima
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai, 980-8575, Japan
| | - Nahoko Higashitani
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai, 980-8575, Japan
| | - Atsushi Higashitani
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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10
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The present and the future of motif-mediated protein-protein interactions. Curr Opin Struct Biol 2018; 50:162-170. [PMID: 29730529 DOI: 10.1016/j.sbi.2018.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 02/07/2018] [Accepted: 04/11/2018] [Indexed: 01/14/2023]
Abstract
Protein-protein interactions (PPIs) are essential to governing virtually all cellular processes. Of particular importance are the versatile motif-mediated interactions (MMIs), which are thus far underrepresented in available interaction data. This is largely due to technical difficulties inherent in the properties of MMIs, but due to the increasing recognition of the vital roles of MMIs in biology, several systematic approaches have recently been developed to detect novel MMIs. Consequently, rapidly growing numbers of motifs are being identified and pursued further for therapeutic applications. In this review, we discuss the current understanding on the diverse functions and disease-relevance of MMIs, the key methodologies for detection of MMIs, and the potential of MMIs for drug development.
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11
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Goel RK, Paczkowska M, Reimand J, Napper S, Lukong KE. Phosphoproteomics Analysis Identifies Novel Candidate Substrates of the Nonreceptor Tyrosine Kinase, Src- related Kinase Lacking C-terminal Regulatory Tyrosine and N-terminal Myristoylation Sites (SRMS). Mol Cell Proteomics 2018; 17:925-947. [PMID: 29496907 DOI: 10.1074/mcp.ra118.000643] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Indexed: 01/23/2023] Open
Abstract
SRMS (Src-related kinase lacking C-terminal regulatory tyrosine and N-terminal myristoylation sites), also known as PTK 70 (Protein tyrosine kinase 70), is a non-receptor tyrosine kinase that belongs to the BRK family of kinases (BFKs). To date less is known about the cellular role of SRMS primarily because of the unidentified substrates or signaling intermediates regulated by the kinase. In this study, we used phosphotyrosine antibody-based immunoaffinity purification in large-scale label-free quantitative phosphoproteomics to identify novel candidate substrates of SRMS. Our analyses led to the identification of 1258 tyrosine-phosphorylated peptides which mapped to 663 phosphoproteins, exclusively from SRMS-expressing cells. DOK1, a previously characterized SRMS substrate, was also identified in our analyses. Functional enrichment analyses revealed that the candidate SRMS substrates were enriched in various biological processes including protein ubiquitination, mitotic cell cycle, energy metabolism and RNA processing, as well as Wnt and TNF signaling. Analyses of the sequence surrounding the phospho-sites in these proteins revealed novel candidate SRMS consensus substrate motifs. We utilized customized high-throughput peptide arrays to validate a subset of the candidate SRMS substrates identified in our MS-based analyses. Finally, we independently validated Vimentin and Sam68, as bona fide SRMS substrates through in vitro and in vivo assays. Overall, our study identified a number of novel and biologically relevant SRMS candidate substrates, which suggests the involvement of the kinase in a vast array of unexplored cellular functions.
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Affiliation(s)
- Raghuveera Kumar Goel
- From the ‡Department of Biochemistry, College of Medicine, 107 Wiggins Road, University of Saskatchewan, Saskatoon S7N 5E5, Saskatchewan, Canada
| | - Marta Paczkowska
- §Computational Biology Program, Ontario Institute for Cancer Research, 661 University Ave Suite 510, Toronto M5G 0A3, Ontario, Canada
| | - Jüri Reimand
- §Computational Biology Program, Ontario Institute for Cancer Research, 661 University Ave Suite 510, Toronto M5G 0A3, Ontario, Canada.,¶Department of Medical Biophysics, University of Toronto, 101 College Street Suite 15-701, Toronto M5G 1L7, Ontario, Canada
| | - Scott Napper
- From the ‡Department of Biochemistry, College of Medicine, 107 Wiggins Road, University of Saskatchewan, Saskatoon S7N 5E5, Saskatchewan, Canada.,‖Vaccine and Infectious Disease Organization - International Vaccine Centre (VIDO-InterVac), 120 Veterinary Road, University of Saskatchewan, Saskatoon S7N 5E3, Saskatchewan, Canada
| | - Kiven Erique Lukong
- From the ‡Department of Biochemistry, College of Medicine, 107 Wiggins Road, University of Saskatchewan, Saskatoon S7N 5E5, Saskatchewan, Canada;
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12
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Li GXH, Vogel C, Choi H. PTMscape: an open source tool to predict generic post-translational modifications and map modification crosstalk in protein domains and biological processes. Mol Omics 2018; 14:197-209. [PMID: 29876573 PMCID: PMC6115748 DOI: 10.1039/c8mo00027a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PTMscape predicts PTM sites using descriptors of sequence and physico-chemical microenvironment, and tests enrichment of single or pairs of PTMs in protein domains.
While tandem mass spectrometry can detect post-translational modifications (PTM) at the proteome scale, reported PTM sites are often incomplete and include false positives. Computational approaches can complement these datasets by additional predictions, but most available tools use prediction models pre-trained for single PTM type by the developers and it remains a difficult task to perform large-scale batch prediction for multiple PTMs with flexible user control, including the choice of training data. We developed an R package called PTMscape which predicts PTM sites across the proteome based on a unified and comprehensive set of descriptors of the physico-chemical microenvironment of modified sites, with additional downstream analysis modules to test enrichment of individual or pairs of PTMs in protein domains. PTMscape is flexible in the ability to process any major modifications, such as phosphorylation and ubiquitination, while achieving the sensitivity and specificity comparable to single-PTM methods and outperforming other multi-PTM tools. Applying this framework, we expanded proteome-wide coverage of five major PTMs affecting different residues by prediction, especially for lysine and arginine modifications. Using a combination of experimentally acquired sites (PSP) and newly predicted sites, we discovered that the crosstalk among multiple PTMs occur more frequently than by random chance in key protein domains such as histone, protein kinase, and RNA recognition motifs, spanning various biological processes such as RNA processing, DNA damage response, signal transduction, and regulation of cell cycle. These results provide a proteome-scale analysis of crosstalk among major PTMs and can be easily extended to other types of PTM.
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Affiliation(s)
- Ginny X H Li
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
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13
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Meng X, Lv Y, Mujahid H, Edelmann MJ, Zhao H, Peng X, Peng Z. Proteome-wide lysine acetylation identification in developing rice (Oryza sativa) seeds and protein co-modification by acetylation, succinylation, ubiquitination, and phosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1866:451-463. [PMID: 29313810 DOI: 10.1016/j.bbapap.2017.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/20/2017] [Accepted: 12/03/2017] [Indexed: 12/31/2022]
Abstract
Protein lysine acetylation is a highly conserved post-translational modification with various biological functions. However, only a limited number of acetylation sites have been reported in plants, especially in cereals, and the function of non-histone protein acetylation is still largely unknown. In this report, we identified 1003 lysine acetylation sites in 692 proteins of developing rice seeds, which greatly extended the number of known acetylated sites in plants. Seven distinguished motifs were detected flanking acetylated lysines. Functional annotation analyses indicated diverse biological processes and pathways engaged in lysine acetylation. Remarkably, we found that several key enzymes in storage starch synthesis pathway and the main storage proteins were heavily acetylated. A comprehensive comparison of the rice acetylome, succinylome, ubiquitome and phosphorylome with available published data was conducted. A large number of proteins carrying multiple kinds of modifications were identified and many of these proteins are known to be key enzymes of vital metabolic pathways. Our study provides extending knowledge of protein acetylation. It will have critical reference value for understanding the mechanisms underlying PTM mediated multiple signal integration in the regulation of metabolism and development in plants.
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Affiliation(s)
- Xiaoxi Meng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Yuanda Lv
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States; Provincial Key Laboratory of Agrobiology, Institute of Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China
| | - Hana Mujahid
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States
| | - Mariola J Edelmann
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, United States
| | - Han Zhao
- Provincial Key Laboratory of Agrobiology, Institute of Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China
| | - Xiaojun Peng
- Department of Bioinformatics, Jingjie PTM Biolab Co. Ltd, Hangzhou, Zhejiang, China
| | - Zhaohua Peng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, MS, United States.
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14
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Caron D, Byrne DP, Thebault P, Soulet D, Landry CR, Eyers PA, Elowe S. Mitotic phosphotyrosine network analysis reveals that tyrosine phosphorylation regulates Polo-like kinase 1 (PLK1). Sci Signal 2016; 9:rs14. [PMID: 27965426 DOI: 10.1126/scisignal.aah3525] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tyrosine phosphorylation is closely associated with cell proliferation. During the cell cycle, serine and threonine phosphorylation plays the leading role, and such phosphorylation events are most dynamic during the mitotic phase of the cell cycle. However, mitotic phosphotyrosine is not well characterized. Although a few functionally-relevant mitotic phosphotyrosine sites have been characterized, evidence suggests that this modification may be more prevalent than previously appreciated. Here, we examined tyrosine phosphorylation in mitotic human cells including those on spindle-associated proteins.? Database mining confirmed ~2000 mitotic phosphotyrosine sites, and network analysis revealed a number of subnetworks that were enriched in tyrosine-phosphorylated proteins, including components of the kinetochore or spindle and SRC family kinases. We identified Polo-like kinase 1 (PLK1), a major signaling hub in the spindle subnetwork, as phosphorylated at the conserved Tyr217 in the kinase domain. Substitution of Tyr217 with a phosphomimetic residue eliminated PLK1 activity in vitro and in cells. Further analysis showed that Tyr217 phosphorylation reduced the phosphorylation of Thr210 in the activation loop, a phosphorylation event necessary for PLK1 activity. Our data indicate that mitotic tyrosine phosphorylation regulated a key serine/threonine kinase hub in mitotic cells and suggested that spatially separating tyrosine phosphorylation events can reveal previously unrecognized regulatory events and complexes associated with specific structures of the cell cycle.
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Affiliation(s)
- Danielle Caron
- Department of Pediatrics, Faculty of Medicine, Université Laval, Centre Hospitalier Universitaire de Québec Research Center, Quebec City, Quebec G1V 4G2, Canada
| | - Dominic P Byrne
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K
| | - Philippe Thebault
- Department of Pediatrics, Faculty of Medicine, Université Laval, Centre Hospitalier Universitaire de Québec Research Center, Quebec City, Quebec G1V 4G2, Canada
| | - Denis Soulet
- Department of Psychiatry et Neurosciences, Faculty of Medicine, Université Laval, Centre Hospitalier Universitaire de Québec Research Center, Quebec City, Quebec G1V 4G2, Canada
| | - Christian R Landry
- Institut de Biologie Intégrative et des Systèmes, Department of Biology, PROTEO, Université Laval, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine, Quebec City, Quebec G1V 0A6, Canada
| | - Patrick A Eyers
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K
| | - Sabine Elowe
- Department of Pediatrics, Faculty of Medicine, Université Laval, Centre Hospitalier Universitaire de Québec Research Center, Quebec City, Quebec G1V 4G2, Canada.
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15
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Hattermann K, Gebhardt H, Krossa S, Ludwig A, Lucius R, Held-Feindt J, Mentlein R. Transmembrane chemokines act as receptors in a novel mechanism termed inverse signaling. eLife 2016; 5:e10820. [PMID: 26796342 PMCID: PMC4739769 DOI: 10.7554/elife.10820] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 12/18/2015] [Indexed: 01/03/2023] Open
Abstract
The transmembrane chemokines CX3CL1/fractalkine and CXCL16 are widely expressed in different types of tumors, often without an appropriate expression of their classical receptors. We observed that receptor-negative cancer cells could be stimulated by the soluble chemokines. Searching for alternative receptors we detected that all cells expressing or transfected with transmembrane chemokine ligands bound the soluble chemokines with high affinity and responded by phosphorylation of intracellular kinases, enhanced proliferation and anti-apoptosis. This activity requires the intracellular domain and apparently the dimerization of the transmembrane chemokine ligand. Thus, shed soluble chemokines can generate auto- or paracrine signals by binding and activating their transmembrane forms. We term this novel mechanism “inverse signaling”. We suppose that inverse signaling is an autocrine feedback and fine-tuning system in the communication between cells that in tumors supports stabilization and proliferation. DOI:http://dx.doi.org/10.7554/eLife.10820.001 The cells that make up an animal need to communicate with each other for a variety of purposes, including controlling the growth and repair of tissues. Commonly, such signaling involves ‘ligand’ molecules binding to specific ‘receptor’ proteins embedded in the cell membrane. When a ligand docks to the right receptor protein, the parts of the receptor inside the cell change shape. This activates signaling pathways within that cell. Types of ligands called transmembrane ligands are found embedded in cell membranes. Some cancer cells have high levels of transmembrane ligands called CXCL16 and CX3CL1 but do not produce the corresponding receptors for these molecules. The part of these ligands that sits outside of the cells can also be separated from the rest of the molecule to produce a soluble ligand that can move around outside the cell. By studying cancer cells using microscopy and biochemical approaches, Hattermann, Gebhardt et al. now show that the soluble forms of CXCL16 and CX3CL1 bind to their transmembrane equivalents. This activates signaling pathways that promote cell growth and make the cancer cells more resistant to cell death. However, this signaling did not occur if the transmembrane ligands were altered to lack the part normally found inside the cell, which suggests that transmembrane CXCL16 and CX3CL1 act as receptors. It was not previously known that a soluble ligand could activate its transmembrane equivalent. Hattermann, Gebhardt et al. have named this process “inverse signaling”, and suggest that it helps to fine-tune the communication between cells. Future experiments will need to study the importance of inverse signaling in living animals and investigate how it works alongside other signaling methods. DOI:http://dx.doi.org/10.7554/eLife.10820.002
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Affiliation(s)
| | | | - Sebastian Krossa
- Department of Structural Biology, Institute of Zoology, Kiel, Germany
| | - Andreas Ludwig
- Institute for Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany
| | - Ralph Lucius
- Department of Anatomy, University of Kiel, Kiel, Germany
| | - Janka Held-Feindt
- Department of Neurosurgery, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Rolf Mentlein
- Department of Anatomy, University of Kiel, Kiel, Germany
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16
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He W, Zhang J, Chen N. Protein kinase-based neural signaling pathways for ginsenosides: a retrospective review. J TRADIT CHIN MED 2015; 35:349-54. [PMID: 26237842 DOI: 10.1016/s0254-6272(15)30109-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ginsenosides are the main active components of ginseng, which have been reported to target brain tissues and produce multiple neuroprotective effects. Ginsenosides have been shown to improve learning ability and memory in normal aged animals, and in an animal model of memory impairment. However, its underlying pharmacological mechanisms are very complicated, especially with regard to its effects on the activation of protein kinases in neurons. Previous reports have shown that some protein kinases may be affected by ginsenosides, including protein kinase C, calcium/calmodulin-dependent protein kinase II, c-Jun-N terminal kinase, and protein tyrosine kinase. In this paper, protein kinases that may underlie the mechanisms of ginsenosides will be discussed.
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17
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Huang SY, Shi SP, Qiu JD, Liu MC. Using support vector machines to identify protein phosphorylation sites in viruses. J Mol Graph Model 2015; 56:84-90. [DOI: 10.1016/j.jmgm.2014.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 12/13/2014] [Accepted: 12/16/2014] [Indexed: 10/24/2022]
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18
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Kumar A, Baycin-Hizal D, Shiloach J, Bowen MA, Betenbaugh MJ. Coupling enrichment methods with proteomics for understanding and treating disease. Proteomics Clin Appl 2015; 9:33-47. [PMID: 25523641 DOI: 10.1002/prca.201400097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/12/2014] [Accepted: 12/15/2014] [Indexed: 12/17/2022]
Abstract
Owing to recent advances in proteomics analytical methods and bioinformatics capabilities there is a growing trend toward using these capabilities for the development of drugs to treat human disease, including target and drug evaluation, understanding mechanisms of drug action, and biomarker discovery. Currently, the genetic sequences of many major organisms are available, which have helped greatly in characterizing proteomes in model animal systems and humans. Through proteomics, global profiles of different disease states can be characterized (e.g. changes in types and relative levels as well as changes in PTMs such as glycosylation or phosphorylation). Although intracellular proteomics can provide a broad overview of physiology of cells and tissues, it has been difficult to quantify the low abundance proteins which can be important for understanding the diseased states and treatment progression. For this reason, there is increasing interest in coupling comparative proteomics methods with subcellular fractionation and enrichment techniques for membranes, nucleus, phosphoproteome, glycoproteome as well as low abundance serum proteins. In this review, we will provide examples of where the utilization of different proteomics-coupled enrichment techniques has aided target and biomarker discovery, understanding the drug targeting mechanism, and mAb discovery. Taken together, these improvements will help to provide a better understanding of the pathophysiology of various diseases including cancer, autoimmunity, inflammation, cardiovascular disease, and neurological conditions, and in the design and development of better medicines for treating these afflictions.
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Affiliation(s)
- Amit Kumar
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA; Antibody Discovery and Protein Engineering, MedImmune LLC, One MedImmune Way, Gaithersburg, MD, USA; Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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19
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Velázquez-Marrero C, Seale GE, Treistman SN, Martin GE. Large conductance voltage- and Ca2+-gated potassium (BK) channel β4 subunit influences sensitivity and tolerance to alcohol by altering its response to kinases. J Biol Chem 2014; 289:29261-72. [PMID: 25190810 DOI: 10.1074/jbc.m114.604306] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tolerance is a well described component of alcohol abuse and addiction. The large conductance voltage- and Ca(2+)-gated potassium channel (BK) has been very useful for studying molecular tolerance. The influence of association with the β4 subunit can be observed at the level of individual channels, action potentials in brain slices, and finally, drinking behavior in the mouse. Previously, we showed that 50 mm alcohol increases both α and αβ4 BK channel open probability, but only α BK develops acute tolerance to this effect. Currently, we explore the possibility that the influence of the β4 subunit on tolerance may result from a striking effect of β4 on kinase modulation of the BK channel. We examine the influence of the β4 subunit on PKA, CaMKII, and phosphatase modulation of channel activity, and on molecular tolerance to alcohol. We record from human BK channels heterologously expressed in HEK 293 cells composed of its core subunit, α alone (Insertless), or co-expressed with the β4 BK auxiliary subunit, as well as, acutely dissociated nucleus accumbens neurons using the cell-attached patch clamp configuration. Our results indicate that BK channels are strongly modulated by activation of specific kinases (PKA and CaMKII) and phosphatases. The presence of the β4 subunit greatly influences this modulation, allowing a variety of outcomes for BK channel activity in response to acute alcohol.
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Affiliation(s)
- Cristina Velázquez-Marrero
- the Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901
| | - Garrett E Seale
- the Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901
| | - Steven N Treistman
- the Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901
| | - Gilles E Martin
- From the Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01604 and
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20
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Ghandi M, Lee D, Mohammad-Noori M, Beer MA. Enhanced regulatory sequence prediction using gapped k-mer features. PLoS Comput Biol 2014; 10:e1003711. [PMID: 25033408 PMCID: PMC4102394 DOI: 10.1371/journal.pcbi.1003711] [Citation(s) in RCA: 295] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 05/28/2014] [Indexed: 12/20/2022] Open
Abstract
Oligomers of length k, or k-mers, are convenient and widely used features for modeling the properties and functions of DNA and protein sequences. However, k-mers suffer from the inherent limitation that if the parameter k is increased to resolve longer features, the probability of observing any specific k-mer becomes very small, and k-mer counts approach a binary variable, with most k-mers absent and a few present once. Thus, any statistical learning approach using k-mers as features becomes susceptible to noisy training set k-mer frequencies once k becomes large. To address this problem, we introduce alternative feature sets using gapped k-mers, a new classifier, gkm-SVM, and a general method for robust estimation of k-mer frequencies. To make the method applicable to large-scale genome wide applications, we develop an efficient tree data structure for computing the kernel matrix. We show that compared to our original kmer-SVM and alternative approaches, our gkm-SVM predicts functional genomic regulatory elements and tissue specific enhancers with significantly improved accuracy, increasing the precision by up to a factor of two. We then show that gkm-SVM consistently outperforms kmer-SVM on human ENCODE ChIP-seq datasets, and further demonstrate the general utility of our method using a Naïve-Bayes classifier. Although developed for regulatory sequence analysis, these methods can be applied to any sequence classification problem. Genomic regulatory elements (enhancers, promoters, and insulators) control the expression of their target genes and are widely believed to play a key role in human development and disease by altering protein concentrations. A fundamental step in understanding enhancers is the development of DNA sequence-based models to predict the tissue specific activity of regulatory elements. Such models facilitate both the identification of the molecular pathways which impinge on enhancer activity through direct transcription factor binding, and the direct evaluation of the impact of specific common or rare genetic variants on enhancer function. We have previously developed a successful sequence-based model for enhancer prediction using a k-mer support vector machine (kmer-SVM). Here, we address a significant limitation of the kmer-SVM approach and present an alternative method using gapped k-mers (gkm-SVM) which exhibits dramatically improved accuracy in all test cases. While we focus on enhancers and transcription factor binding, our method can be applied to improve a much broader class of sequence analysis problems, including proteins and RNA. In addition, we expect that most k-mer based methods can be significantly improved by simply using the generalized k-mer count method that we present in this paper. We believe this improved model will enable significant contributions to our understanding of the human regulatory system.
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Affiliation(s)
- Mahmoud Ghandi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Dongwon Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Morteza Mohammad-Noori
- School of Mathematics, Statistics and Computer Science, University of Tehran, Tehran, Iran
- School of Computer Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | - Michael A. Beer
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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21
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Ow GS, Ivshina AV, Fuentes G, Kuznetsov VA. Identification of two poorly prognosed ovarian carcinoma subtypes associated with CHEK2 germ-line mutation and non-CHEK2 somatic mutation gene signatures. Cell Cycle 2014; 13:2262-80. [PMID: 24879340 PMCID: PMC4111681 DOI: 10.4161/cc.29271] [Citation(s) in RCA: 21] [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: 04/03/2014] [Revised: 05/14/2014] [Accepted: 05/17/2014] [Indexed: 01/08/2023] Open
Abstract
High-grade serous ovarian cancer (HG-SOC), a major histologic type of epithelial ovarian cancer (EOC), is a poorly-characterized, heterogeneous and lethal disease where somatic mutations of TP53 are common and inherited loss-of-function mutations in BRCA1/2 predispose to cancer in 9.5-13% of EOC patients. However, the overall burden of disease due to either inherited or sporadic mutations is not known. We performed bioinformatics analyses of mutational and clinical data of 334 HG-SOC tumor samples from The Cancer Genome Atlas to identify novel tumor-driving mutations, survival-significant patient subgroups and tumor subtypes potentially driven by either hereditary or sporadic factors. We identified a sub-cluster of high-frequency mutations in 22 patients and 58 genes associated with DNA damage repair, apoptosis and cell cycle. Mutations of CHEK2, observed with the highest intensity, were associated with poor therapy response and overall survival (OS) of these patients (P = 8.00e-05), possibly due to detrimental effect of mutations at the nuclear localization signal. A 21-gene mutational prognostic signature significantly stratifies patients into relatively low or high-risk subgroups with 5-y OS of 37% or 6%, respectively (P = 7.31e-08). Further analysis of these genes and high-risk subgroup revealed 2 distinct classes of tumors characterized by either germline mutations of genes such as CHEK2, RPS6KA2 and MLL4, or somatic mutations of other genes in the signature. Our results could provide improvement in prediction and clinical management of HG-SOC, facilitate our understanding of this complex disease, guide the design of targeted therapeutics and improve screening efforts to identify women at high-risk of hereditary ovarian cancers distinct from those associated with BRCA1/2 mutations.
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Affiliation(s)
| | | | - Gloria Fuentes
- Bioinformatics Institute; A*STAR; Singapore
- Center for Life Science Technologies (CLST); RIKEN; Saitama, Japan
| | - Vladimir A Kuznetsov
- Bioinformatics Institute; A*STAR; Singapore
- Division of Software & Information Systems; School of Computer Engineering; Nanyang Technological University; Singapore
- School for Integrative Science and Engineering; National University of Singapore; Singapore
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22
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Mehta MS, Dolfi SC, Bronfenbrener R, Bilal E, Chen C, Moore D, Lin Y, Rahim H, Aisner S, Kersellius RD, Teh J, Chen S, Toppmeyer DL, Medina DJ, Ganesan S, Vazquez A, Hirshfield KM. Metabotropic glutamate receptor 1 expression and its polymorphic variants associate with breast cancer phenotypes. PLoS One 2013; 8:e69851. [PMID: 23922822 PMCID: PMC3724883 DOI: 10.1371/journal.pone.0069851] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 06/12/2013] [Indexed: 12/22/2022] Open
Abstract
Several epidemiological studies have suggested a link between melanoma and breast cancer. Metabotropic glutamate receptor 1 (GRM1), which is involved in many cellular processes including proliferation and differentiation, has been implicated in melanomagenesis, with ectopic expression of GRM1 causing malignant transformation of melanocytes. This study was undertaken to evaluate GRM1 expression and polymorphic variants in GRM1 for associations with breast cancer phenotypes. Three single nucleotide polymorphisms (SNPs) in GRM1 were evaluated for associations with breast cancer clinicopathologic variables. GRM1 expression was evaluated in human normal and cancerous breast tissue and for in vitro response to hormonal manipulation. Genotyping was performed on genomic DNA from over 1,000 breast cancer patients. Rs6923492 and rs362962 genotypes associated with age at diagnosis that was highly dependent upon the breast cancer molecular phenotype. The rs362962 TT genotype also associated with risk of estrogen receptor or progesterone receptor positive breast cancer. In vitro analysis showed increased GRM1 expression in breast cancer cells treated with estrogen or the combination of estrogen and progesterone, but reduced GRM1 expression with tamoxifen treatment. Evaluation of GRM1 expression in human breast tumor specimens demonstrated significant correlations between GRM1 staining with tissue type and molecular features. Furthermore, analysis of gene expression data from primary breast tumors showed that high GRM1 expression correlated with a shorter distant metastasis-free survival as compared to low GRM1 expression in tamoxifen-treated patients. Additionally, induced knockdown of GRM1 in an estrogen receptor positive breast cancer cell line correlated with reduced cell proliferation. Taken together, these findings suggest a functional role for GRM1 in breast cancer.
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Affiliation(s)
- Madhura S. Mehta
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Sonia C. Dolfi
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Roman Bronfenbrener
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Erhan Bilal
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Chunxia Chen
- Department of Biometrics, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Dirk Moore
- Department of Biometrics, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Yong Lin
- Department of Biometrics, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Hussein Rahim
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Seena Aisner
- Department of Pathology and Laboratory Medicine, University of Medicine and Dentistry of New Jersey - New Jersey Medical School, Newark, New Jersey, United States of America
| | - Romona D. Kersellius
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Jessica Teh
- Department of Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Suzie Chen
- Department of Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Deborah L. Toppmeyer
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Dan J. Medina
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Shridar Ganesan
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Alexei Vazquez
- Department of Radiation Oncology, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey- Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Kim M. Hirshfield
- Division of Medical Oncology, Department of Medicine, The Cancer Institute of New Jersey/University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
- * E-mail:
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23
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CK1δ kinase activity is modulated by Chk1-mediated phosphorylation. PLoS One 2013; 8:e68803. [PMID: 23861943 PMCID: PMC3701638 DOI: 10.1371/journal.pone.0068803] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/01/2013] [Indexed: 12/19/2022] Open
Abstract
CK1δ, a member of the casein kinase 1 family, is involved in the regulation of various cellular processes and has been associated with the pathophysiology of neurodegenerative diseases and cancer. Therefore recently, interest in generating highly specific inhibitors for personalized therapy has increased enormously. However, the efficacy of newly developed inhibitors is affected by the phosphorylation state of CK1δ. Cellular kinases phosphorylating CK1δ within its C-terminal domain have been identified but still more information regarding the role of site-specific phosphorylation in modulating the activity of CK1δ is required. Here we show that Chk1 phosphorylates rat CK1δ at serine residues 328, 331, 370, and threonine residue 397 as well as the human CK1δ transcription variants 1 and 2. CK1δ mutant proteins bearing one, two or three mutations at these identified phosphorylation sites exhibited significant differences in their kinetic properties compared to wild-type CK1δ. Additionally, CK1δ co-precipitates with Chk1 from HT1080 cell extracts and activation of cellular Chk1 resulted in a significant decrease in cellular CK1δ kinase activity. Taken together, these data point towards a possible regulatory relationship between Chk1 and CK1δ.
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24
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The Escherichia coli phosphotyrosine proteome relates to core pathways and virulence. PLoS Pathog 2013. [PMID: 23785281 DOI: 10.1371/journal.ppat.1003403.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While phosphotyrosine modification is an established regulatory mechanism in eukaryotes, it is less well characterized in bacteria due to low prevalence. To gain insight into the extent and biological importance of tyrosine phosphorylation in Escherichia coli, we used immunoaffinity-based phosphotyrosine peptide enrichment combined with high resolution mass spectrometry analysis to comprehensively identify tyrosine phosphorylated proteins and accurately map phosphotyrosine sites. We identified a total of 512 unique phosphotyrosine sites on 342 proteins in E. coli K12 and the human pathogen enterohemorrhagic E. coli (EHEC) O157:H7, representing the largest phosphotyrosine proteome reported to date in bacteria. This large number of tyrosine phosphorylation sites allowed us to define five phosphotyrosine site motifs. Tyrosine phosphorylated proteins belong to various functional classes such as metabolism, gene expression and virulence. We demonstrate for the first time that proteins of a type III secretion system (T3SS), required for the attaching and effacing (A/E) lesion phenotype characteristic for intestinal colonization by certain EHEC strains, are tyrosine phosphorylated by bacterial kinases. Yet, A/E lesion and metabolic phenotypes were unaffected by the mutation of the two currently known tyrosine kinases, Etk and Wzc. Substantial residual tyrosine phosphorylation present in an etk wzc double mutant strongly indicated the presence of hitherto unknown tyrosine kinases in E. coli. We assess the functional importance of tyrosine phosphorylation and demonstrate that the phosphorylated tyrosine residue of the regulator SspA positively affects expression and secretion of T3SS proteins and formation of A/E lesions. Altogether, our study reveals that tyrosine phosphorylation in bacteria is more prevalent than previously recognized, and suggests the involvement of phosphotyrosine-mediated signaling in a broad range of cellular functions and virulence.
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25
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Hansen AM, Chaerkady R, Sharma J, Díaz-Mejía JJ, Tyagi N, Renuse S, Jacob HKC, Pinto SM, Sahasrabuddhe NA, Kim MS, Delanghe B, Srinivasan N, Emili A, Kaper JB, Pandey A. The Escherichia coli phosphotyrosine proteome relates to core pathways and virulence. PLoS Pathog 2013; 9:e1003403. [PMID: 23785281 PMCID: PMC3681748 DOI: 10.1371/journal.ppat.1003403] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 04/22/2013] [Indexed: 01/31/2023] Open
Abstract
While phosphotyrosine modification is an established regulatory mechanism in eukaryotes, it is less well characterized in bacteria due to low prevalence. To gain insight into the extent and biological importance of tyrosine phosphorylation in Escherichia coli, we used immunoaffinity-based phosphotyrosine peptide enrichment combined with high resolution mass spectrometry analysis to comprehensively identify tyrosine phosphorylated proteins and accurately map phosphotyrosine sites. We identified a total of 512 unique phosphotyrosine sites on 342 proteins in E. coli K12 and the human pathogen enterohemorrhagic E. coli (EHEC) O157:H7, representing the largest phosphotyrosine proteome reported to date in bacteria. This large number of tyrosine phosphorylation sites allowed us to define five phosphotyrosine site motifs. Tyrosine phosphorylated proteins belong to various functional classes such as metabolism, gene expression and virulence. We demonstrate for the first time that proteins of a type III secretion system (T3SS), required for the attaching and effacing (A/E) lesion phenotype characteristic for intestinal colonization by certain EHEC strains, are tyrosine phosphorylated by bacterial kinases. Yet, A/E lesion and metabolic phenotypes were unaffected by the mutation of the two currently known tyrosine kinases, Etk and Wzc. Substantial residual tyrosine phosphorylation present in an etk wzc double mutant strongly indicated the presence of hitherto unknown tyrosine kinases in E. coli. We assess the functional importance of tyrosine phosphorylation and demonstrate that the phosphorylated tyrosine residue of the regulator SspA positively affects expression and secretion of T3SS proteins and formation of A/E lesions. Altogether, our study reveals that tyrosine phosphorylation in bacteria is more prevalent than previously recognized, and suggests the involvement of phosphotyrosine-mediated signaling in a broad range of cellular functions and virulence. While phosphotyrosine modification is established in eukaryote cell signaling, it is less characterized in bacteria. Despite that deletion of bacterial tyrosine kinases is known to affect various cellular functions and virulence of bacterial pathogens, few phosphotyrosine proteins are currently known. To gain insight into the extent and biological function of tyrosine phosphorylation in E. coli, we carried out an in-depth phosphotyrosine protein profiling using a mass spectrometry-based proteomics approach. Our study on E. coli K12 and the human pathogen enterohemorrhagic E. coli (EHEC) O157:H7, which is a common cause of food-borne outbreaks of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome, reveal that tyrosine phosphorylation is far more prevalent than previously recognized. Target proteins are involved in a broad range of cellular functions and virulence. Proteins of the type III secretion system (T3SS), required for the attaching and effacing lesion phenotype characteristic for intestinal colonization by EHEC, are tyrosine phosphorylated. The expression of these T3SS proteins and A/E lesion formation is affected by a tyrosine phosphorylated residue on the regulator SspA. Also, our data indicates the presence of hitherto unknown E. coli tyrosine kinases. Overall, tyrosine phosphorylation seems to be involved in controlling cellular core processes and virulence of bacteria.
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Affiliation(s)
- Anne-Marie Hansen
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Raghothama Chaerkady
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jyoti Sharma
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- Manipal University, Manipal, India
| | - J. Javier Díaz-Mejía
- Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
- Department of Biology, Wilfrid Laurier University, Waterloo, Canada
| | - Nidhi Tyagi
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Santosh Renuse
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Harrys K. C. Jacob
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Sneha M. Pinto
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- Manipal University, Manipal, India
| | - Nandini A. Sahasrabuddhe
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
- Manipal University, Manipal, India
| | - Min-Sik Kim
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
| | | | | | - Andrew Emili
- Department of Biology, Wilfrid Laurier University, Waterloo, Canada
| | - James B. Kaper
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (JBK); (AP)
| | - Akhilesh Pandey
- Institute of Bioinformatics, International Tech Park, Bangalore, India
- McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Pathology and Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail: (JBK); (AP)
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26
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Macdonald JI, Dick FA. Posttranslational modifications of the retinoblastoma tumor suppressor protein as determinants of function. Genes Cancer 2013; 3:619-33. [PMID: 23634251 DOI: 10.1177/1947601912473305] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The retinoblastoma tumor suppressor protein (pRB) plays an integral role in G1-S checkpoint control and consequently is a frequent target for inactivation in cancer. The RB protein can function as an adaptor, nucleating components such as E2Fs and chromatin regulating enzymes into the same complex. For this reason, pRB's regulation by posttranslational modifications is thought to be critical. pRB is phosphorylated by a number of different kinases such as cyclin dependent kinases (Cdks), p38 MAP kinase, Chk1/2, Abl, and Aurora b. Although phosphorylation of pRB by Cdks has been extensively studied, activities regulated through phosphorylation by other kinases are just starting to be understood. As well as being phosphorylated, pRB is acetylated, methylated, ubiquitylated, and SUMOylated. Acetylation, methylation, and SUMOylation play roles in pRB mediated gene silencing. Ubiquitinylation of pRB promotes its degradation and may be used to regulate apoptosis. Recent proteomic data have revealed that pRB is posttranslationally modified to a much greater extent than previously thought. This new information suggests that many unknown pathways affect pRB regulation. This review focuses on posttranslational modifications of pRB and how they influence its function. The final part of the review summarizes new phosphorylation sites from accumulated proteomic data and discusses the possibilities that might arise from this data.
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Affiliation(s)
- James I Macdonald
- Western University, London Regional Cancer Program, Department of Biochemistry, London, ON, Canada
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27
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Abstract
Cells respond to external stimuli by transducing signals through a series of intracellular molecules and eliciting an appropriate response. The cascade of events through which the signals are transduced include post-translational modifications such as phosphorylation and ubiquitylation in addition to formation of multi-protein complexes. Improvements in biological mass spectrometry and protein/peptide microarray technology have tremendously improved our ability to probe proteins, protein complexes, and signaling pathways in a high-throughput fashion. Today, a single mass spectrometry-based investigation of a signaling pathway has the potential to uncover the large majority of known signaling intermediates painstakingly characterized over decades in addition to discovering a number of novel ones. Here, we discuss various proteomic strategies to characterize signaling pathways and provide protocols for phosphoproteomic analysis.
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Affiliation(s)
- H C Harsha
- Institute of Bioinformatics, International Technology Park, Bangalore, India
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28
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Clark R, Nosie A, Walker T, Faralli JA, Filla MS, Barrett-Wilt G, Peters DM. Comparative genomic and proteomic analysis of cytoskeletal changes in dexamethasone-treated trabecular meshwork cells. Mol Cell Proteomics 2012; 12:194-206. [PMID: 23105009 DOI: 10.1074/mcp.m112.019745] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Changes in the actin cytoskeleton, especially the formation of cross-linked actin networks (CLANs) are thought to contribute to the increased intraocular pressure observed in primary open-angle and steroid-induced glaucoma. To better understand the effects of glucocorticoids, we employed a shotgun method to analyze global changes in the cytoskeleton and integrin signaling pathways following dexamethasone (DEX) treatment of human trabecular meshwork (HTM) cells. RNA and cell lysates were obtained from HTM cells incubated with or without DEX. Changes in protein expression were determined by mass spectrometry (MS) following differential centrifugation of cell lysates to enrich for low-abundance cytoskeletal and signaling proteins, proteolytic digestion, and a titanium dioxide column to enrich for phosphopeptides. Results were validated by Western blots. Changes in RNA levels were determined with gene arrays and RT-PCR. Overall, MS identified 318 cytoskeleton associated proteins. Five of these proteins (PDLIM1, FGFR1OP, leiomodin-1, ZO-2 and LRP16A) were only detected in DEX-treated cells by MS. However, only PDLIM1 showed a statistically significant increase at the RNA level. Other proteins with differences at both the RNA and protein levels included β3 integrin, caveolin-1, Borg2, raftlin1, PI-3 kinase regulatory subunit α, transgelin, and filamin B. By immunofluorescence microscopy filamin B and PDLIM1 showed enhanced expression in human trabecular meshwork cells, but only PDLIM1 demonstrated significant localization within CLANs. Finally, MS showed that some of the cytoskeleton proteins (Borg2, leiomodin-1, LRP16A, raftlin1 and CKAP4) contained phosphorylated residues. This study suggests that DEX affects the expression of cytoskeleton proteins at the transcriptional and translational level and shows that a combined genomic and proteomic approach can be used for rapid analysis of proteins in the TM. It also shows that DEX altered the expression of components (PDLIM1 and β3 integrins) involved in CLAN formation and provides new findings into the effects of glucocorticoids on the cytoskeleton.
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Affiliation(s)
- Ross Clark
- Departments of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin 53706, USA
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29
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Ochs MF. Issues in Omics Data Integration for Gene Set Analysis and Aberrant Pathway Identification. Drug Dev Res 2012. [DOI: 10.1002/ddr.21046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michael F. Ochs
- Department of Oncology; Johns Hopkins University; Baltimore; MD; 21218; USA
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30
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Liu BA, Engelmann BW, Nash PD. The language of SH2 domain interactions defines phosphotyrosine-mediated signal transduction. FEBS Lett 2012; 586:2597-605. [PMID: 22569091 DOI: 10.1016/j.febslet.2012.04.054] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 04/25/2012] [Accepted: 04/26/2012] [Indexed: 10/28/2022]
Abstract
Natural languages arise in an unpremeditated fashion resulting in words and syntax as individual units of information content that combine in a manner that is both complex and contextual, yet intuitive to a native reader. In an analogous manner, protein interaction domains such as the Src Homology 2 (SH2) domain recognize and "read" the information contained within their cognate peptide ligands to determine highly selective protein-protein interactions that underpin much of cellular signal transduction. Herein, we discuss how contextual sequence information, which combines the use of permissive and non-permissive residues within a parent motif, is a defining feature of selective interactions across SH2 domains. Within a system that reads phosphotyrosine modifications this provides crucial information to distinguish preferred interactions. This review provides a structural and biochemical overview of SH2 domain binding to phosphotyrosine-containing peptide motifs and discusses how the diverse set of SH2 domains is able to differentiate phosphotyrosine ligands.
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Affiliation(s)
- Bernard A Liu
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Ave., Toronto, Ontario, Canada M5G 1X5
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