Multidimensional profiling of the Toxoplasma gondii proteome
Universally, external signals are transduced and propagated in cells by secondary messengers. In the asexual and replicating stages of apicomplexan parasites, these pathways initiate and sustain transitions within the lytic cycle responsible for parasite spread and pathogenesis. Among these early-br...
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| Format: | Thesis |
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Massachusetts Institute of Technology
2024
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| Online Access: | https://hdl.handle.net/1721.1/157865 |
| _version_ | 1824458312972763136 |
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| author | Herneisen, Alice Lydia |
| author2 | Lourido, Sebastian |
| author_facet | Lourido, Sebastian Herneisen, Alice Lydia |
| author_sort | Herneisen, Alice Lydia |
| collection | MIT |
| description | Universally, external signals are transduced and propagated in cells by secondary messengers. In the asexual and replicating stages of apicomplexan parasites, these pathways initiate and sustain transitions within the lytic cycle responsible for parasite spread and pathogenesis. Among these early-branching parasitic protists are the etiologic agents of the widespread, persistent, and deadly human diseases malaria (Plasmodium spp.) and toxoplasmosis (Toxoplasma gondii), making the understanding of these parasite signaling pathways of global importance. Although components of secondary messenger signaling pathways are conserved among apicomplexans and higher eukaryotes, 800 million years of divergence from existing model organisms precludes identification of parasite-specific secondary messenger responses or a priori reconstruction of their signaling pathways.
This thesis addresses that gap. I have adapted state-of-the-art proteomics methods to study the proteome of the model apicomplexan T. gondii across multiple dimensions: abundance, stability, time, and space. Chapter 2 describes how I employed thermal proteome profiling to identify the target of an antiparasitic compound, thereby enhancing our understanding of parasite calcium signaling pathways. In a conceptual leap, I applied this method to systematically identify calcium-responsive proteins on the basis of biochemical interactions with this second messenger in Chapter 3. From this analysis, the protein phosphatase PP1 emerged as an unanticipated calcium-responsive phosphatase along with dozens of novel proteins belonging to this critical signaling network.
Signaling pathways communicate to orchestrate complex cellular processes, yet in apicomplexan parasites they are often studied in isolation. In Chapter 4, I identify a node linking three key second messenger pathways in T. gondii: calcium, cyclic GMP, and cyclic AMP. The apicomplexan-specific kinase SPARK regulates the AGC kinases PKG, PKA C1, and PKA C3, which together control transitions within the asexual cycle of this important family of parasites. |
| first_indexed | 2025-02-19T04:23:54Z |
| format | Thesis |
| id | mit-1721.1/157865 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2025-02-19T04:23:54Z |
| publishDate | 2024 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1578652024-12-19T03:21:02Z Multidimensional profiling of the Toxoplasma gondii proteome Herneisen, Alice Lydia Lourido, Sebastian Massachusetts Institute of Technology. Department of Biology Universally, external signals are transduced and propagated in cells by secondary messengers. In the asexual and replicating stages of apicomplexan parasites, these pathways initiate and sustain transitions within the lytic cycle responsible for parasite spread and pathogenesis. Among these early-branching parasitic protists are the etiologic agents of the widespread, persistent, and deadly human diseases malaria (Plasmodium spp.) and toxoplasmosis (Toxoplasma gondii), making the understanding of these parasite signaling pathways of global importance. Although components of secondary messenger signaling pathways are conserved among apicomplexans and higher eukaryotes, 800 million years of divergence from existing model organisms precludes identification of parasite-specific secondary messenger responses or a priori reconstruction of their signaling pathways. This thesis addresses that gap. I have adapted state-of-the-art proteomics methods to study the proteome of the model apicomplexan T. gondii across multiple dimensions: abundance, stability, time, and space. Chapter 2 describes how I employed thermal proteome profiling to identify the target of an antiparasitic compound, thereby enhancing our understanding of parasite calcium signaling pathways. In a conceptual leap, I applied this method to systematically identify calcium-responsive proteins on the basis of biochemical interactions with this second messenger in Chapter 3. From this analysis, the protein phosphatase PP1 emerged as an unanticipated calcium-responsive phosphatase along with dozens of novel proteins belonging to this critical signaling network. Signaling pathways communicate to orchestrate complex cellular processes, yet in apicomplexan parasites they are often studied in isolation. In Chapter 4, I identify a node linking three key second messenger pathways in T. gondii: calcium, cyclic GMP, and cyclic AMP. The apicomplexan-specific kinase SPARK regulates the AGC kinases PKG, PKA C1, and PKA C3, which together control transitions within the asexual cycle of this important family of parasites. Ph.D. 2024-12-18T18:16:52Z 2024-12-18T18:16:52Z 2023-09 2023-11-15T18:01:00.905Z Thesis https://hdl.handle.net/1721.1/157865 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology |
| spellingShingle | Herneisen, Alice Lydia Multidimensional profiling of the Toxoplasma gondii proteome |
| title | Multidimensional profiling of the Toxoplasma gondii proteome |
| title_full | Multidimensional profiling of the Toxoplasma gondii proteome |
| title_fullStr | Multidimensional profiling of the Toxoplasma gondii proteome |
| title_full_unstemmed | Multidimensional profiling of the Toxoplasma gondii proteome |
| title_short | Multidimensional profiling of the Toxoplasma gondii proteome |
| title_sort | multidimensional profiling of the toxoplasma gondii proteome |
| url | https://hdl.handle.net/1721.1/157865 |
| work_keys_str_mv | AT herneisenalicelydia multidimensionalprofilingofthetoxoplasmagondiiproteome |