Dynamics of photosynthetic pigment-protein complexes in Chlamydomonas reinhardtii
Abstract/Contents
- Abstract
- Photosynthesis, the conversion of solar energy into fixed chemical energy, is a critical biological process that supports nearly all life on earth. This process involves the absorption of light by pigment-protein complexes that make up thylakoid or photosynthetic membranes, and electron transfer reactions that ultimately generate NADPH and establish a proton gradient used to synthesize ATP. These cellular reducing equivalents and high energy compounds are then utilized in carbon fixation reactions that occur in the Calvin Benson Bassham Cycle (reductive pentose phosphate pathway). However, photosynthesis is also an inherently dangerous process as excess absorbed light that cannot be used for photochemistry (electron transport and CO2 fixation) can elicit the formation of reactive oxygen species that can severely damage the cell. Therefore, photosynthesis must be a highly regulated and extremely flexible process. We are just beginning to understand all of the components of the photosynthetic apparatus and how they function in the face of an ever-changing environment. This thesis explores novel components and functions associated with photosynthesis, with an emphasis on pigment-protein complex dynamics. All of the work was performed using the single-celled green alga Chlamydomonas reinhardtii, an excellent model for the study of photosynthesis. The first introductory chapter highlights unifying themes related to the control and plasticity of photosynthesis. The second chapter focuses on two novel thylakoid membrane proteins, CPLD38 and CPLD49, both of which are critical for photoautotrophic growth and impact the accumulation of the cytochrome b6f complex. The third chapter highlights a critical, yet previously undiscovered role for linear tetrapyrroles (bilins) in the maintenance of photosystem I. Central to this study is the control of photosynthetic processes as cells transition from darkness to light. The fourth chapter focuses on a critical redox carrier protein, FDX5, which is absolutely required for growth in the dark where it may be involved in maintaining proper membrane structure and composition, and other processes that are potentially redox-associated. The fifth chapter addresses how photosynthesis is adjusted during nutrient deprivation and specifically elucidates unique aspects of photoautotrophic nitrogen deprivation (an often encountered condition in the environment) that allow the photosynthetic apparatus to be preserved even though the cells are unable to fix much inorganic carbon. The sixth chapter presents preliminary evidence that identifies specific steps in the assembly of the photosynthetic apparatus that appear to be protected from atmospheric O2. Overall, this work unmasks novel components associated with the function and biogenesis of thylakoid membranes, revealing mechanisms critical for maintaining photosynthetic function in a dynamic environment.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Wittkopp, Tyler Michael |
|---|---|
| Associated with | Stanford University, Department of Biology. |
| Primary advisor | Grossman, Arthur (Arthur R.) |
| Primary advisor | Mudgett, Mary Beth, 1967- |
| Thesis advisor | Grossman, Arthur (Arthur R.) |
| Thesis advisor | Mudgett, Mary Beth, 1967- |
| Thesis advisor | Cyert, Martha S, 1958- |
| Thesis advisor | Spormann, Alfred M |
| Advisor | Cyert, Martha S, 1958- |
| Advisor | Spormann, Alfred M |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Tyler Michael Wittkopp. |
|---|---|
| Note | Submitted to the Department of Biology. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Tyler Michael Wittkopp
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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