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Midchain Arginylation of ⍺-Tubulin at E77 Regulates Microtubule Dynamics via MAP1S Brittany MacTaggart
- Format:
- Book
- Thesis/Dissertation
- Author/Creator:
- MacTaggart, Brittany, author.
- Language:
- English
- Subjects (All):
- Cellular biology.
- Biochemistry.
- Molecular biology.
- Developmental biology.
- 0379.
- 0487.
- 0307.
- 0758.
- Local Subjects:
- Cellular biology.
- Biochemistry.
- Molecular biology.
- Developmental biology.
- 0379.
- 0487.
- 0307.
- 0758.
- Physical Description:
- 1 electronic resource (228 pages)
- Contained In:
- Dissertations Abstracts International 86-07B
- Place of Publication:
- Ann Arbor : ProQuest Dissertations and Theses, 2024
- Language Note:
- English
- Summary:
- Arginylation is a post-translational modification (PTM) in which arginine is transferred from a tRNA molecule onto a protein by arginyltransferase 1 (ATE1). In mice, Ate1 deletion results in embryonic lethality due to various developmental defects, but the protein targets of arginylation that mediate these effects remain poorly defined. Initially, ATE1 was believed to only arginylate N-terminally exposed glutamate and aspartate residues, which targeted a protein for proteasomal degradation. More recently, ATE1 has been shown to arginylate the carboxylate sidechains of glutamate and aspartate residues within intact proteins without affecting protein stability. This greatly expands the list of potential targets and functions of arginylation.Here, we attempt to further our understanding of both the targets and the functional consequences of midchain arginylation. In Chapter 2, we report the first global screen specifically for midchain arginylation. We generated antibodies that recognize midchain arginylation in any sequence context and used them for immunoaffinity enrichment of cell and tissue extracts. Using mass spectrometry, we identified ~100 proteins that likely undergo ATE1- dependent midchain arginylation. These proteins are enriched in specific cellular functions, including the cytoskeleton.Previous studies have found that Ate1 knockout causes cytoskeletal defects both in culture and in vivo. Some of these phenotypes have been linked to β-actin arginylation, but the role of other arginylated cytoskeletal proteins has not been studied. In Chapter 3, we review known functions of PTMs in the cytoskeleton. In Chapter 4, we identify and study the function of midchain arginylation at Glu77 of ⍺-tubulin. We find that cells depleted of Ate1 or overexpressing non-arginylatable ⍺-tubulinE77A show reduced microtubule growth rate and increased microtubule stability. In both cases, this is accompanied by an increase in the fraction of the stabilizing protein MAP1S associated with microtubules, and knockdown of Map1s is sufficient to rescue microtubule growth rate and stability. Together, this work adds to our understanding of midchain arginylation by providing a tool to identify targets of midchain arginylation and exploring the functional consequences of a single midchain arginylation site on ⍺-tubulin
- Notes:
- Source: Dissertations Abstracts International, Volume: 86-07, Section: B.
- Advisors: Kashina, Anna Committee members: Bi, Erfei; Grishchuk, Ekaterina L.; Holzbaur, Erika L. F.; Svitkina, Tatyana M.
- Ph.D. University of Pennsylvania 2024
- Local Notes:
- School code: 0175
- ISBN:
- 9798302183309
- Access Restriction:
- Restricted for use by site license
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