Coregulation of Gene Expression by mRNA and tRNA Modifications / Robert Jordan Ontiveros.

Format:

Book

Thesis/Dissertation

Author/Creator:

Ontiveros, Robert Jordan, author.

Contributor:

University of Pennsylvania. Biochemistry and Molecular Biophysics, degree granting institution.

Language:

English

Subjects (All):

Biochemistry.

Molecular biology.

Biochemistry and Molecular Biophysics--Penn dissertations.

Penn dissertations--Biochemistry and Molecular Biophysics.

Local Subjects:

Biochemistry.

Molecular biology.

Biochemistry and Molecular Biophysics--Penn dissertations.

Penn dissertations--Biochemistry and Molecular Biophysics.

Physical Description:

1 online resource (129 pages)

Contained In:

Dissertations Abstracts International 84-08B.

Place of Publication:

[Philadelphia, Pennsylvania] : University of Pennsylvania, 2022.

Ann Arbor : ProQuest Dissertations & Theses, 2022

Language Note:

English

Summary:

RNA modifications are concurrently found on nearly all RNA species and can dramatically alter the properties and expression of RNA. Modifications on different RNA species can affect gene expression through several mechanisms such as localization, stability, and translation efficiency. There has been a great effort by the field to understand the functional impact of individual modifications in isolated RNAs, but the interplay of both mRNA and tRNA modifications and their respective enzymes is currently understudied. Here, we investigate how the N6-methyladenosine (m6A) mRNA modification can regulate gene expression through two distinct mechanisms: (1) a direct interaction with mcm5s2U34-tRNA to modulate translation and (2) modulation of mRNA stability and translation via the interaction between the m6A demethylase FTO and the tRNA methyltransferase TRMT10A. To investigate the direct interaction, we analyzed publicly available datasets and classified a pool of genes whose coding regions are enriched in both m6A as well as codons specifically dependent on mcm5s2U34-modified tRNAs. Further analysis of ribosome profiling data indicates that this group of genes exhibit basally low association with ribosomes. Using specially designed reporters, we show that loss of modifications to both the mRNA codon and tRNA anticodon has the greatest negative effect on translation. Towards our investigation of enzymatic m6A modulation, we observe that loss of TRMT10A induces a reduction in m1G-tRNA, but surprisingly also induces increased m6A-mRNA. Following this, we show that the physical interaction of these two distinct enzymes is critical in maintaining proper transcriptomic m6A-mRNA, suggesting a new non-enzymatic secondary role of TRMT10A as a partner protein to facilitate FTO's demethylation activity. Analysis of ribosome profiling and m6A-RIP-seq data reveals that most the activity of FTO-TRMT10A generally supports translation. Altogether, these results demonstrate two distinct mechanisms by which m6A-mRNA and tRNA-modifying enzymes can be controlled and leveraged by cells to regulate and coordinate post-transcriptional events.

Notes:

Source: Dissertations Abstracts International, Volume: 84-08, Section: B.

Advisors: Liu, Kathy Fange; Committee members: Lynch, Kristen; Gupta, Kushol; Tian, Bin.

Department: Biochemistry and Molecular Biophysics.

Ph.D. University of Pennsylvania 2022.

Local Notes:

School code: 0175

ISBN:

9798374413335

Access Restriction:

Restricted for use by site license.

This item is not available from ProQuest Dissertations & Theses.