Structure-Based Algorithms for Protein-Protein Interaction Prediction

Total Page:16

File Type:pdf, Size:1020Kb

Structure-Based Algorithms for Protein-Protein Interaction Prediction Structure-based algorithms for protein-protein interaction prediction by Raghavendra Hosur Submitted to the Department of Materials Science and Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2012 © Massachusetts Institute of Technology 2012. All rights reserved. Author................................................................ Department of Materials Science and Engineering May 17, 2012 Certified by. Bonnie Berger Professor of Applied Mathematics Thesis Supervisor Accepted by . Prof. Gerbrand Ceder Chairman, Department Committee on Graduate Students ii Structure-based algorithms for protein-protein interaction prediction by Raghavendra Hosur Submitted to the Department of Materials Science and Engineering on May 17, 2012, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract Protein-protein interactions (PPIs) play a central role in all biological processes. Akin to the complete sequencing of genomes, complete descriptions of interactomes is a fundamental step towards a deeper understanding of biological processes, and has a vast potential to impact systems biology, genomics, molecular biology and thera- peutics. PPIs are critical in maintenance of cellular integrity, metabolism, transcrip- tion/translation, and cell-cell communication. This thesis develops new methods that significantly advance our efforts at structure- based approaches to predict PPIs and boost confidence in emerging high-throughput (HTP) data. The aims of this thesis are, 1) to utilize physicochemical properties of protein interfaces to better predict the putative interacting regions and increase coverage of PPI prediction, 2) increase confidence in HTP datasets by identifying likely experimental errors, and 3) provide residue-level information that gives us in- sights into structure-function relationships in PPIs. Taken together, these methods will vastly expand our understanding of macromolecular networks. In this thesis, I introduce two computational approaches for structure-based protein- protein interaction prediction: iWRAP and Coev2Net. iWRAP is an interface thread- ing approach that utilizes biophysical properties specific to protein interfaces to im- prove PPI prediction. Unlike previous structure-based approaches that use single structures to make predictions, iWRAP first builds profiles that characterize the hy- drophobic, electrostatic and structural properties specific to protein interfaces from multiple interface alignments. Compatibility with these profiles is used to predict the putative interface region between the two proteins. In addition to improved interface prediction, iWRAP provides better accuracy and close to 50% increase in coverage on genome-scale PPI prediction tasks. As an application, we effectively combine iWRAP with genomic data to identify novel cancer related genes involved in chromatin remod- eling, nucleosome organization and ribonuclear complex assembly – processes known to be critical in cancer. Coev2Net addresses some of the limitations of iWRAP, and provides techniques iii to increase coverage and accuracy even further. Unlike earlier sequence and struc- ture profiles, Coev2Net explicitly models long-distance correlations at protein inter- faces. By formulating interface co-evolution as a high-dimensional sampling problem, we enrich sequence/structure profiles with artificial interacting homologus sequences for families which do not have known multiple interacting homologs. We build a spanning-tree based graphical model induced by the simulated sequences as our in- terface profile. Cross-validation results indicate that this approach is as good as previ- ous methods at PPI prediction. We show that Coev2Net’s predictions correlate with experimental observations and experimentally validate some of the high-confidence predictions. Furthermore, we demonstrate how analysis of the predicted interfaces together with human genomic variation data can help us understand the role of these mutations in disease and normal cells. Thesis Supervisor: Bonnie Berger Title: Professor of Applied Mathematics iv Publications Some ideas and figures have appeared previously in the following publications: Park, D., Singh, R., Xu, J., Hosur, R. and Berger, B. Struct2Net: a webser- vice to predict protein-protein interactions using a structure-based approach, Nucleic Acids Research, 38(W508-15), Jul 2010. Hosur, R., Xu, J., Bienkowska, J. and Berger, B. iWRAP: an interface threading approach with application to cancer-related protein-protein interactions, Journal of Molecular Biology, 405(5):1295-1310. Feb 2011. The article and image were featured on the cover Hosur, R., Peng, J., Arunachalam, V., Stelzl, U., Xu, J., Perrimon, N., Bi- enkowska, J. and Berger, B. A computational framework for boosting confidence in high-throughput protein-protein interaction datasets, submitted Hosur, R., Singh, R. and Berger, B. Sparse estimation for structural variability, Algorithms for Molecular Biology, 6:12. Jun 2011. Selected for fast-track publication from WABI 2010 Bryan, A., Starner, J., Hosur, R., Clark, P. and Berger, B. Structure-based prediction reveals capping motifs that inhibit β-helix aggregation, Proceedings of the National Academy of Sciences, 108(27):11099-11104, Jul 2011. Daniels, N., Hosur, R., Cowen, L. and Berger, B. SMURFLite: combining sim- plified Markov random fields with simulated evolution improves remote homology detection for beta-structural proteins into the twilight zone, Bioinformatics, 2012, v doi: 10.1093/bioinformatics/bts110. vi Acknowledgments I would like to take this opportunity to express my heartfelt appreciation and grat- itude to many who have supported me throughout my graduate studies at MIT. First, I am indebted to my advisor, Prof Bonnie Berger, for her support, advice and mentorship. None of this would have been possible without her constant guidance, motivation and encouragement, even during the tough times of my PhD. Her never- ending enthusiasm for research, positive attitude and belief in me have helped me evolve both academically and personally. It is something that I will always remember and cherish. I would like to especially thank, Jadwiga Bienkowska, for her support, help and encouragement during my thesis. Her knowledge, combined with her enthusiasm in helping answer all the technical challenges that we faced during the course of this thesis helped me learn a lot about the field. I also appreciate her taking time out from her busy schedule to meet us frequently to discuss about my thesis and provide invaluable suggestions. I would like to thank my thesis committee, Prof Collin Stultz, Prof Samuel Allen and Prof Polina Anikeeva for their feedback and suggestions on my thesis. I want to thank the current as well as past members of the Berger lab. My discus- sions and brain-storming sessions with Jian over the last year have helped me gain from his vast knowledge. Discussions with Rohit, Vinu, Luke, Jason, Michael, Jerome and Charlie have also helped me think about problems from a broader perspective. vii I also want to thank George, Po-Ru, Mark, Hadar and Patrick for comments and suggestions during group meetings that have helped me improve as a researcher. I want to thank Patrice Macaluso, who always welcomed me to the lab with a smile and some home-made treats. I want to thank all my friends here at MIT – Aniruddh, Ahmed, Andrea, Vikrant, Vaibhav, Vivek, Kashi, Harshad, Pari, Chaitanya, Oshani, Sahil, Kedia, Karthik, Murali, Varun, Neeraj who have made the stay a fun and exciting experience. I will always cherish the “latt”, “dudo” and “muddy” sessions with the gang. I want to especially thank Manas, Navin and Angad for their constant support and friendship. Finally, I want to thank my parents who have made immense sacrifices so that me and my sisters can be where we are today. Their unwavering love and belief in me makes me want to be a better person every day. This thesis is as much for them as it is for me. viii Contents 1 Introduction 1 1.1 Proteins . 2 1.1.1 Protein structure determination . 5 1.2 Protein-protein interactions . 7 1.2.1 Types of PPIs . 8 1.2.2 Structural features . 8 1.2.3 Physico-chemical features . 9 1.2.4 Evolutionary features . 13 1.3 Experimental methods for PPI detection . 14 1.3.1 Low throughput screens . 14 1.3.2 High throughput screens . 14 1.3.3 Limitations of experimental techniques . 17 1.4 Computational methods for PPI prediction . 18 1.4.1 Indirect methods . 18 1.4.2 Direct methods . 19 1.4.3 Data integration methods . 20 1.5 Medical impact . 22 1.6 Organization of the thesis . 23 2 Struct2Net: structure-based approach to PPI prediction 25 ix 2.1 Background . 25 2.2 Methods overview . 27 2.3 Evaluation . 30 2.4 Conclusion . 31 3 iWRAP: an interface threading approach for PPI prediction 35 3.1 Introduction . 35 3.2 Results . 38 3.2.1 Overview of the threading algorithm . 38 3.2.2 Interface validation . 41 3.2.3 PPI Prediction: yeast genome . 50 3.2.4 iWRAP predicts novel cancer-related interactions . 53 3.3 Materials and Methods . 57 3.3.1 Stage 1: Template construction . 57 3.3.2 Stage 2: Aligning query sequences to templates . 58 3.3.3 Stage 3: Interface scoring . 59 3.3.4 Stage 4: PPI prediction . 61 3.3.5 Training and test sets . 63 3.4 Discussion . 64 4 Coev2Net: a computational framework for boosting confidence in HTP PPI datasets 67 4.1 Background . 67 4.2 Results . 69 4.2.1 The Coev2Net framework . 69 4.2.2 Benchmarking Coev2Net . 71 4.2.3 MAPK interactome validation . 73 4.2.4 Experimental validation of predictions . 74 x 4.2.5 Abundance of missense SNPs at predicted interfaces . 76 4.2.6 Novel potential cross-talk regulatory mechanism . 78 4.3 Methods . 79 4.3.1 Simulating interface co-evolution . 81 4.4 Discussion . 84 5 Conclusions 87 A Appendix:iWRAP 93 A.1 Evaluation of alignments . 93 A.2 Methods . 95 A.2.1 Templates . 95 A.2.2 Multiple Interface Alignment . 96 A.2.3 Genomic Predictions: S.cerevisiae . 96 B Appendix:Coev2Net 101 B.1 Proof of equivalence of simulated co-evolution and high-dimensional sampling .
Recommended publications
  • A University of Sussex Phd Thesis Available Online Via
    A University of Sussex PhD thesis Available online via Sussex Research Online: http://sro.sussex.ac.uk/ This thesis is protected by copyright which belongs to the author. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Please visit Sussex Research Online for more information and further details Exploring interactions between Epstein- Barr virus transcription factor Zta and The Human Genome By IJIEL BARAK NARANJO PEREZ FERNANDEZ A Thesis submitted for the degree of Doctor of Philosophy University Of Sussex School of Life Sciences September 2017 ii I hereby declare that this thesis has not been and will not be, submitted in whole or in part to another University for the award of any other degree. Signature:…………………………..…………………………..……………………… iii Acknowledgements I want to thank Professor Alison J Sinclair for her guidance, mentoring and above all continuous patience. During the time that I’ve been part of her lab I’ve appreciated her wisdom as an educator her foresight as a scientist and tremendous love as a parent. I wish that someday soon rather than later her teachings are reflected in my person and career; hopefully inspiring others like me. Thanks to Professor Michelle West for her help whenever needed or offered. Her sincere and honest feedback, something that I only learned to appreciate after my personal scientific insight was developed.
    [Show full text]
  • Molecular and Physiological Basis for Hair Loss in Near Naked Hairless and Oak Ridge Rhino-Like Mouse Models: Tracking the Role of the Hairless Gene
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2006 Molecular and Physiological Basis for Hair Loss in Near Naked Hairless and Oak Ridge Rhino-like Mouse Models: Tracking the Role of the Hairless Gene Yutao Liu University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Life Sciences Commons Recommended Citation Liu, Yutao, "Molecular and Physiological Basis for Hair Loss in Near Naked Hairless and Oak Ridge Rhino- like Mouse Models: Tracking the Role of the Hairless Gene. " PhD diss., University of Tennessee, 2006. https://trace.tennessee.edu/utk_graddiss/1824 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Yutao Liu entitled "Molecular and Physiological Basis for Hair Loss in Near Naked Hairless and Oak Ridge Rhino-like Mouse Models: Tracking the Role of the Hairless Gene." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Life Sciences. Brynn H. Voy, Major Professor We have read this dissertation and recommend its acceptance: Naima Moustaid-Moussa, Yisong Wang, Rogert Hettich Accepted for the Council: Carolyn R.
    [Show full text]
  • Location Analysis of Estrogen Receptor Target Promoters Reveals That
    Location analysis of estrogen receptor ␣ target promoters reveals that FOXA1 defines a domain of the estrogen response Jose´ e Laganie` re*†, Genevie` ve Deblois*, Ce´ line Lefebvre*, Alain R. Bataille‡, Franc¸ois Robert‡, and Vincent Gigue` re*†§ *Molecular Oncology Group, Departments of Medicine and Oncology, McGill University Health Centre, Montreal, QC, Canada H3A 1A1; †Department of Biochemistry, McGill University, Montreal, QC, Canada H3G 1Y6; and ‡Laboratory of Chromatin and Genomic Expression, Institut de Recherches Cliniques de Montre´al, Montreal, QC, Canada H2W 1R7 Communicated by Ronald M. Evans, The Salk Institute for Biological Studies, La Jolla, CA, July 1, 2005 (received for review June 3, 2005) Nuclear receptors can activate diverse biological pathways within general absence of large scale functional data linking these putative a target cell in response to their cognate ligands, but how this binding sites with gene expression in specific cell types. compartmentalization is achieved at the level of gene regulation is Recently, chromatin immunoprecipitation (ChIP) has been used poorly understood. We used a genome-wide analysis of promoter in combination with promoter or genomic DNA microarrays to occupancy by the estrogen receptor ␣ (ER␣) in MCF-7 cells to identify loci recognized by transcription factors in a genome-wide investigate the molecular mechanisms underlying the action of manner in mammalian cells (20–24). This technology, termed 17␤-estradiol (E2) in controlling the growth of breast cancer cells. ChIP-on-chip or location analysis, can therefore be used to deter- We identified 153 promoters bound by ER␣ in the presence of E2. mine the global gene expression program that characterize the Motif-finding algorithms demonstrated that the estrogen re- action of a nuclear receptor in response to its natural ligand.
    [Show full text]
  • Essential Genes and Their Role in Autism Spectrum Disorder
    University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2017 Essential Genes And Their Role In Autism Spectrum Disorder Xiao Ji University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Bioinformatics Commons, and the Genetics Commons Recommended Citation Ji, Xiao, "Essential Genes And Their Role In Autism Spectrum Disorder" (2017). Publicly Accessible Penn Dissertations. 2369. https://repository.upenn.edu/edissertations/2369 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/2369 For more information, please contact [email protected]. Essential Genes And Their Role In Autism Spectrum Disorder Abstract Essential genes (EGs) play central roles in fundamental cellular processes and are required for the survival of an organism. EGs are enriched for human disease genes and are under strong purifying selection. This intolerance to deleterious mutations, commonly observed haploinsufficiency and the importance of EGs in pre- and postnatal development suggests a possible cumulative effect of deleterious variants in EGs on complex neurodevelopmental disorders. Autism spectrum disorder (ASD) is a heterogeneous, highly heritable neurodevelopmental syndrome characterized by impaired social interaction, communication and repetitive behavior. More and more genetic evidence points to a polygenic model of ASD and it is estimated that hundreds of genes contribute to ASD. The central question addressed in this dissertation is whether genes with a strong effect on survival and fitness (i.e. EGs) play a specific oler in ASD risk. I compiled a comprehensive catalog of 3,915 mammalian EGs by combining human orthologs of lethal genes in knockout mice and genes responsible for cell-based essentiality.
    [Show full text]
  • The Genome of Schmidtea Mediterranea and the Evolution Of
    OPEN ArtICLE doi:10.1038/nature25473 The genome of Schmidtea mediterranea and the evolution of core cellular mechanisms Markus Alexander Grohme1*, Siegfried Schloissnig2*, Andrei Rozanski1, Martin Pippel2, George Robert Young3, Sylke Winkler1, Holger Brandl1, Ian Henry1, Andreas Dahl4, Sean Powell2, Michael Hiller1,5, Eugene Myers1 & Jochen Christian Rink1 The planarian Schmidtea mediterranea is an important model for stem cell research and regeneration, but adequate genome resources for this species have been lacking. Here we report a highly contiguous genome assembly of S. mediterranea, using long-read sequencing and a de novo assembler (MARVEL) enhanced for low-complexity reads. The S. mediterranea genome is highly polymorphic and repetitive, and harbours a novel class of giant retroelements. Furthermore, the genome assembly lacks a number of highly conserved genes, including critical components of the mitotic spindle assembly checkpoint, but planarians maintain checkpoint function. Our genome assembly provides a key model system resource that will be useful for studying regeneration and the evolutionary plasticity of core cell biological mechanisms. Rapid regeneration from tiny pieces of tissue makes planarians a prime De novo long read assembly of the planarian genome model system for regeneration. Abundant adult pluripotent stem cells, In preparation for genome sequencing, we inbred the sexual strain termed neoblasts, power regeneration and the continuous turnover of S. mediterranea (Fig. 1a) for more than 17 successive sib- mating of all cell types1–3, and transplantation of a single neoblast can rescue generations in the hope of decreasing heterozygosity. We also developed a lethally irradiated animal4. Planarians therefore also constitute a a new DNA isolation protocol that meets the purity and high molecular prime model system for stem cell pluripotency and its evolutionary weight requirements of PacBio long-read sequencing12 (Extended Data underpinnings5.
    [Show full text]
  • Table S2.Up Or Down Regulated Genes in Tcof1 Knockdown Neuroblastoma N1E-115 Cells Involved in Differentbiological Process Anal
    Table S2.Up or down regulated genes in Tcof1 knockdown neuroblastoma N1E-115 cells involved in differentbiological process analysed by DAVID database Pop Pop Fold Term PValue Genes Bonferroni Benjamini FDR Hits Total Enrichment GO:0044257~cellular protein catabolic 2.77E-10 MKRN1, PPP2R5C, VPRBP, MYLIP, CDC16, ERLEC1, MKRN2, CUL3, 537 13588 1.944851 8.64E-07 8.64E-07 5.02E-07 process ISG15, ATG7, PSENEN, LOC100046898, CDCA3, ANAPC1, ANAPC2, ANAPC5, SOCS3, ENC1, SOCS4, ASB8, DCUN1D1, PSMA6, SIAH1A, TRIM32, RNF138, GM12396, RNF20, USP17L5, FBXO11, RAD23B, NEDD8, UBE2V2, RFFL, CDC GO:0051603~proteolysis involved in 4.52E-10 MKRN1, PPP2R5C, VPRBP, MYLIP, CDC16, ERLEC1, MKRN2, CUL3, 534 13588 1.93519 1.41E-06 7.04E-07 8.18E-07 cellular protein catabolic process ISG15, ATG7, PSENEN, LOC100046898, CDCA3, ANAPC1, ANAPC2, ANAPC5, SOCS3, ENC1, SOCS4, ASB8, DCUN1D1, PSMA6, SIAH1A, TRIM32, RNF138, GM12396, RNF20, USP17L5, FBXO11, RAD23B, NEDD8, UBE2V2, RFFL, CDC GO:0044265~cellular macromolecule 6.09E-10 MKRN1, PPP2R5C, VPRBP, MYLIP, CDC16, ERLEC1, MKRN2, CUL3, 609 13588 1.859332 1.90E-06 6.32E-07 1.10E-06 catabolic process ISG15, RBM8A, ATG7, LOC100046898, PSENEN, CDCA3, ANAPC1, ANAPC2, ANAPC5, SOCS3, ENC1, SOCS4, ASB8, DCUN1D1, PSMA6, SIAH1A, TRIM32, RNF138, GM12396, RNF20, XRN2, USP17L5, FBXO11, RAD23B, UBE2V2, NED GO:0030163~protein catabolic process 1.81E-09 MKRN1, PPP2R5C, VPRBP, MYLIP, CDC16, ERLEC1, MKRN2, CUL3, 556 13588 1.87839 5.64E-06 1.41E-06 3.27E-06 ISG15, ATG7, PSENEN, LOC100046898, CDCA3, ANAPC1, ANAPC2, ANAPC5, SOCS3, ENC1, SOCS4,
    [Show full text]
  • The Genetics of Bipolar Disorder
    Molecular Psychiatry (2008) 13, 742–771 & 2008 Nature Publishing Group All rights reserved 1359-4184/08 $30.00 www.nature.com/mp FEATURE REVIEW The genetics of bipolar disorder: genome ‘hot regions,’ genes, new potential candidates and future directions A Serretti and L Mandelli Institute of Psychiatry, University of Bologna, Bologna, Italy Bipolar disorder (BP) is a complex disorder caused by a number of liability genes interacting with the environment. In recent years, a large number of linkage and association studies have been conducted producing an extremely large number of findings often not replicated or partially replicated. Further, results from linkage and association studies are not always easily comparable. Unfortunately, at present a comprehensive coverage of available evidence is still lacking. In the present paper, we summarized results obtained from both linkage and association studies in BP. Further, we indicated new potential interesting genes, located in genome ‘hot regions’ for BP and being expressed in the brain. We reviewed published studies on the subject till December 2007. We precisely localized regions where positive linkage has been found, by the NCBI Map viewer (http://www.ncbi.nlm.nih.gov/mapview/); further, we identified genes located in interesting areas and expressed in the brain, by the Entrez gene, Unigene databases (http://www.ncbi.nlm.nih.gov/entrez/) and Human Protein Reference Database (http://www.hprd.org); these genes could be of interest in future investigations. The review of association studies gave interesting results, as a number of genes seem to be definitively involved in BP, such as SLC6A4, TPH2, DRD4, SLC6A3, DAOA, DTNBP1, NRG1, DISC1 and BDNF.
    [Show full text]
  • Novel Potential ALL Low-Risk Markers Revealed by Gene
    Leukemia (2003) 17, 1891–1900 & 2003 Nature Publishing Group All rights reserved 0887-6924/03 $25.00 www.nature.com/leu BIO-TECHNICAL METHODS (BTS) Novel potential ALL low-risk markers revealed by gene expression profiling with new high-throughput SSH–CCS–PCR J Qiu1,5, P Gunaratne2,5, LE Peterson3, D Khurana2, N Walsham2, H Loulseged2, RJ Karni1, E Roussel4, RA Gibbs2, JF Margolin1,6 and MC Gingras1,6 1Texas Children’s Cancer Center and Department of Pediatrics; 2Human Genome Sequencing Center, Department of Molecular and Human Genetics; 3Department of Internal Medicine; 1,2,3 are all departments of Baylor College of Medicine, Baylor College of Medicine, Houston, TX, USA; and 4BioTher Corporation, Houston, TX, USA The current systems of risk grouping in pediatric acute t(1;19), BCR-ABL t(9;22), and MLL-AF4 t(4;11).1 These chromo- lymphoblastic leukemia (ALL) fail to predict therapeutic suc- somal modifications and other clinical findings such as age and cess in 10–35% of patients. To identify better predictive markers of clinical behavior in ALL, we have developed an integrated initial white blood cell count (WBC) define pediatric ALL approach for gene expression profiling that couples suppres- subgroups and are used as diagnostic and prognostic markers to sion subtractive hybridization, concatenated cDNA sequencing, assign specific risk-adjusted therapies. For instance, 1.0 to 9.9- and reverse transcriptase real-time quantitative PCR. Using this year-old patients with none of the determinant chromosomal approach, a total of 600 differentially expressed genes were translocation (NDCT) mentioned above but with a WBC higher identified between t(4;11) ALL and pre-B ALL with no determi- than 50 000 cells/ml are associated with higher risk group.2 nant chromosomal translocation.
    [Show full text]
  • A High-Throughput Approach to Uncover Novel Roles of APOBEC2, a Functional Orphan of the AID/APOBEC Family
    Rockefeller University Digital Commons @ RU Student Theses and Dissertations 2018 A High-Throughput Approach to Uncover Novel Roles of APOBEC2, a Functional Orphan of the AID/APOBEC Family Linda Molla Follow this and additional works at: https://digitalcommons.rockefeller.edu/ student_theses_and_dissertations Part of the Life Sciences Commons A HIGH-THROUGHPUT APPROACH TO UNCOVER NOVEL ROLES OF APOBEC2, A FUNCTIONAL ORPHAN OF THE AID/APOBEC FAMILY A Thesis Presented to the Faculty of The Rockefeller University in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy by Linda Molla June 2018 © Copyright by Linda Molla 2018 A HIGH-THROUGHPUT APPROACH TO UNCOVER NOVEL ROLES OF APOBEC2, A FUNCTIONAL ORPHAN OF THE AID/APOBEC FAMILY Linda Molla, Ph.D. The Rockefeller University 2018 APOBEC2 is a member of the AID/APOBEC cytidine deaminase family of proteins. Unlike most of AID/APOBEC, however, APOBEC2’s function remains elusive. Previous research has implicated APOBEC2 in diverse organisms and cellular processes such as muscle biology (in Mus musculus), regeneration (in Danio rerio), and development (in Xenopus laevis). APOBEC2 has also been implicated in cancer. However the enzymatic activity, substrate or physiological target(s) of APOBEC2 are unknown. For this thesis, I have combined Next Generation Sequencing (NGS) techniques with state-of-the-art molecular biology to determine the physiological targets of APOBEC2. Using a cell culture muscle differentiation system, and RNA sequencing (RNA-Seq) by polyA capture, I demonstrated that unlike the AID/APOBEC family member APOBEC1, APOBEC2 is not an RNA editor. Using the same system combined with enhanced Reduced Representation Bisulfite Sequencing (eRRBS) analyses I showed that, unlike the AID/APOBEC family member AID, APOBEC2 does not act as a 5-methyl-C deaminase.
    [Show full text]
  • Disruption of the Anaphase-Promoting Complex Confers Resistance to TTK Inhibitors in Triple-Negative Breast Cancer
    Disruption of the anaphase-promoting complex confers resistance to TTK inhibitors in triple-negative breast cancer K. L. Thua,b, J. Silvestera,b, M. J. Elliotta,b, W. Ba-alawib,c, M. H. Duncana,b, A. C. Eliaa,b, A. S. Merb, P. Smirnovb,c, Z. Safikhanib, B. Haibe-Kainsb,c,d,e, T. W. Maka,b,c,1, and D. W. Cescona,b,f,1 aCampbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada M5G 1L7; bPrincess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada M5G 1L7; cDepartment of Medical Biophysics, University of Toronto, Toronto, ON, Canada M5G 1L7; dDepartment of Computer Science, University of Toronto, Toronto, ON, Canada M5G 1L7; eOntario Institute for Cancer Research, Toronto, ON, Canada M5G 0A3; and fDepartment of Medicine, University of Toronto, Toronto, ON, Canada M5G 1L7 Contributed by T. W. Mak, December 27, 2017 (sent for review November 9, 2017; reviewed by Mark E. Burkard and Sabine Elowe) TTK protein kinase (TTK), also known as Monopolar spindle 1 (MPS1), ator of the spindle assembly checkpoint (SAC), which delays is a key regulator of the spindle assembly checkpoint (SAC), which anaphase until all chromosomes are properly attached to the functions to maintain genomic integrity. TTK has emerged as a mitotic spindle, TTK has an integral role in maintaining genomic promising therapeutic target in human cancers, including triple- integrity (6). Because most cancer cells are aneuploid, they are negative breast cancer (TNBC). Several TTK inhibitors (TTKis) are heavily reliant on the SAC to adequately segregate their abnormal being evaluated in clinical trials, and an understanding of karyotypes during mitosis.
    [Show full text]
  • Mrna Editing, Processing and Quality Control in Caenorhabditis Elegans
    | WORMBOOK mRNA Editing, Processing and Quality Control in Caenorhabditis elegans Joshua A. Arribere,*,1 Hidehito Kuroyanagi,†,1 and Heather A. Hundley‡,1 *Department of MCD Biology, UC Santa Cruz, California 95064, †Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan, and ‡Medical Sciences Program, Indiana University School of Medicine-Bloomington, Indiana 47405 ABSTRACT While DNA serves as the blueprint of life, the distinct functions of each cell are determined by the dynamic expression of genes from the static genome. The amount and specific sequences of RNAs expressed in a given cell involves a number of regulated processes including RNA synthesis (transcription), processing, splicing, modification, polyadenylation, stability, translation, and degradation. As errors during mRNA production can create gene products that are deleterious to the organism, quality control mechanisms exist to survey and remove errors in mRNA expression and processing. Here, we will provide an overview of mRNA processing and quality control mechanisms that occur in Caenorhabditis elegans, with a focus on those that occur on protein-coding genes after transcription initiation. In addition, we will describe the genetic and technical approaches that have allowed studies in C. elegans to reveal important mechanistic insight into these processes. KEYWORDS Caenorhabditis elegans; splicing; RNA editing; RNA modification; polyadenylation; quality control; WormBook TABLE OF CONTENTS Abstract 531 RNA Editing and Modification 533 Adenosine-to-inosine RNA editing 533 The C. elegans A-to-I editing machinery 534 RNA editing in space and time 535 ADARs regulate the levels and fates of endogenous dsRNA 537 Are other modifications present in C.
    [Show full text]
  • Genome-Wide Gene Expression Profiling of the Angelman Syndrome
    European Journal of Human Genetics (2010) 18, 1228–1235 & 2010 Macmillan Publishers Limited All rights reserved 1018-4813/10 www.nature.com/ejhg ARTICLE Genome-wide gene expression profiling of the Angelman syndrome mice with Ube3a mutation Daren Low1 and Ken-Shiung Chen*,1 Angelman syndrome (AS) is a human neurological disorder caused by lack of maternal UBE3A expression in the brain. UBE3A is known to function as both an ubiquitin-protein ligase (E3) and a coactivator for steroid receptors. Many ubiquitin targets, as well as interacting partners, of UBE3A have been identified. However, the pathogenesis of AS, and how deficiency of maternal UBE3A can upset cellular homeostasis, remains vague. In this study, we performed a genome-wide microarray analysis on the maternal Ube3a-deficient (Ube3amÀ/p+) AS mouse to search for genes affected in the absence of Ube3a. We observed 64 differentially expressed transcripts (7 upregulated and 57 downregulated) showing more than 1.5-fold differences in expression (Po0.05). Pathway analysis shows that these genes are implicated in three major networks associated with cell signaling, nervous system development and cell death. Using quantitative reverse-transcription PCR, we validated the differential expression of genes (Fgf7, Glra1, Mc1r, Nr4a2, Slc5a7 and Epha6) that show functional relevance to AS phenotype. We also show that the protein level of melanocortin 1 receptor (Mc1r) and nuclear receptor subfamily 4, group A, member 2 (Nr4a2) in the AS mice cerebellum is decreased relative to that of the wild-type mice. Consistent with this finding, expression of small-interfering RNA that targets Ube3a in P19 cells caused downregulation of Mc1r and Nr4a2, whereas overexpression of Ube3a results in the upregulation of Mc1r and Nr4a2.
    [Show full text]