Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations January 2016 Deciphering the role of Hsp31 as a multitasking chaperone Kiran Aslam Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Recommended Citation Aslam, Kiran, "Deciphering the role of Hsp31 as a multitasking chaperone" (2016). Open Access Dissertations. 1242. https://docs.lib.purdue.edu/open_access_dissertations/1242 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School Form 30 Updated 12/26/2015 PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Kiran Aslam Entitled DECIPHERING THE ROLE OF HSP31 AS A MULTITASKING CHAPERONE For the degree of Doctor of Philosophy Is approved by the final examining committee: Tony R Hazbun Chair Jean-Christophe Rochet Douglas J. LaCount Ruben C Aguilar To the best of my knowledge and as understood by the student in the Thesis/Dissertation Agreement, Publication Delay, and Certification Disclaimer (Graduate School Form 32), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy of Integrity in Research” and the use of copyright material. Tony R Hazbun Approved by Major Professor(s): Jean-Christophe Rochet 06/07/16 Approved by: Head of the Departmental Graduate Program Date i DECIPHERING THE ROLE OF HSP31 AS A MULTITASKING CHAPERONE Dissertation Submitted to the Faculty of Purdue University by Kiran Aslam In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy i August 2016 Purdue University West Lafayette, Indiana ii For my parents; Aslam and Mukhtiar And to my wonderful husband Khizar Rouf ii iii ACKNOWLEDGEMENTS Though only my name appears on the cover of this thesis, earning a doctorate and writing a thesis is certainly not done single-handedly. I owe my gratitude to all those people who have contributed to its production and because of them my experience at Purdue University has been one that I will cherish forever. I would like to reflect on all those people who have supported and inspired me not only in the scientific arena, but also on a personal level throughout this period. First of all, my deepest gratitude goes to my advisor, Dr. Tony Hazbun. I have been fortunate to have an advisor who trained me how to question thoughts and deliver ideas. He gave me the freedom to explore on my own, and at the same time guided me to recover whenever I faced obstacles. I would like to thank him for his patience in mentoring me as a scientist. Without his guidance, this work would not exist. I extend my sincere gratitude to Dr. Jean-Christophe Rochet, who has been always there to listen and give advice. I am sincerely grateful to him for the insightful feedback that helped me sort out the technical details of enzymatic assay presented in this thesis. I am iii also thankful to him for carefully reading and commenting on many revisions of my JBC manuscript. I am indebted to him for his continuous encouragement and guidance that will stay with me for the rest of my life. I am also thankful to Dr. Douglas J. LaCount for reading my reports, providing thought-provoking comments that helped me move iv forward in positive direction. I am grateful to him for constructive criticisms at different level of graduate school that have helped me focus on my goals. I also like to thank him and his group members for letting me use their lab’s equipment and reagents. Next, I would like to thank Dr. Ruben C Aguilar who is one of the best teachers that I have had in my life. I am grateful to him for teaching me important concepts in cellular biology that help me understand and enrich my ideas. Next, I would like to acknowledge past and present members of Dr. Hazbun’s group, for their friendship, valuable discussion and technical help with scientific projects. I appreciate the efforts of the many undergraduate students who helped me make the media and buffers to run various experiments on time. I am also thankful to the faculty and staff of Medicinal Chemistry and Molecular Pharmacology department for their various form of support during my graduate study. Most importantly, I would like to express my heart-felt gratitude to my family and friends who have helped me stay sane through these difficult years. I greatly appreciate their love, support and belief in me that has been strength for me. I have to give a special mention to iv my husband Khizar Rouf who worries about me more than I worry about myself. Finally, I appreciate the United State Education Foundation in Pakistan and International Institute of Education for providing me Fulbright fellowship that was a huge financial support for me. v TABLE OF CONTENTS Page LIST OF ABBREVIATIONS ............................................................................................ xi ABSTRACT ..................................................................................................................... xiii CHAPTER 1. INTRODUCTION .................................................................................... 1 1.1 High-fidelity protein quality control ...................................................................... 1 1.1.1 Consequences of Protein Misfolding .............................................................. 2 1.1.2 Role of chaperone in protein homeostasis ....................................................... 2 1.1.2.1 Heat Shock Proteins .................................................................................. 4 1.1.2.2 Small heat shock proteins .......................................................................... 6 1.2 Neurodegenerative diseases ................................................................................... 7 1.2.1 Mitochondrial dysfunction in neurodegenerative disease ............................. 11 1.2.2 Amyloidogenesis ........................................................................................... 12 1.3 Parkinson’s disease .............................................................................................. 15 v 1.3.1 Risk factors .................................................................................................... 16 1.3.2 Genetic factors ............................................................................................... 18 1.3.3 Diagnosis ....................................................................................................... 18 1.3.4 Clinical presentation ...................................................................................... 20 1.3.4.1 Motor symptoms ...................................................................................... 20 vi Page 1.3.4.2 Non-motor symptoms .............................................................................. 21 1.3.5 Management of Parkinson’s disease ............................................................. 23 1.3.6 Yeast Model of Parkinson’s disease .............................................................. 24 1.4 Prion disease ........................................................................................................ 25 1.4.1 Prions in yeast ............................................................................................... 29 1.4.2 Structural organization .................................................................................. 30 1.4.2.1 Prion forming domain .............................................................................. 30 1.4.2.2 De novo prion formation ......................................................................... 33 1.4.3 Effect of heat shock proteins on prion propagation ...................................... 34 1.4.4 Prion associated toxicity ................................................................................ 38 1.5 DJ-1/ThiJ/Pfp1 superfamily ................................................................................. 38 1.5.1 Human DJ-1 .................................................................................................. 40 1.5.2 The yeast Hsp31 mini family ........................................................................ 41 1.6 Role of Hsp31 in cellular stress response ............................................................ 41 vi 1.7 Comparison of Hsp31 paralogs ........................................................................... 45 1.8 Hsp31 role in redox homeostasis ......................................................................... 48 CHAPTER 2. HSP31 IS A STRESS-RESPONSE CHAPERONE THAT INTERVENES IN THE PROTEIN MISFOLDING PROCESS ...................................... 50 2.1 Abstract ................................................................................................................ 50 2.2 Introduction .......................................................................................................... 51 2.3 Results .................................................................................................................. 53 2.3.1 Hsp31 is an integral part of the yeast cellular stress response ...................... 53 vii Page 2.3.2 Hsp31 methylglyoxalase activity is not required for rescue of α-syn-mediated toxicity ...................................................................................................................... 60 2.3.3 D-lactate supplementation suppresses the steady state level of α-syn