자료유형  

 학위논문

Control Number  

0016931362

International Standard Book Number  

9798379750565

Dewey Decimal Classification Number  

574

Main Entry-Personal Name  

Stoute, Julian.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Pennsylvania., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(170 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 84-12, Section: B.

General Note  

Advisor: Liu, Kathy;Bonasio, Roberto.

Dissertation Note  

Thesis (Ph.D.)--University of Pennsylvania, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약The ribosome is an essential component of the central dogma of life. It is primarily responsible for translation, in which mRNA transcripts are decoded, and proteins are synthesized. The ribosome consists primarily of ribosomal RNA (rRNA). After transcription, it is processed in a series of steps where it is folded, cut, and chemically modified until mature ribosome subunits are formed and exported out of the nucleus. One of the early steps of the process of ribosome biogenesis involves the methyltransferase enzyme DIMT1. This enzyme is essential for processing 18S rRNA, which makes up the ribosome's small subunit (SSU). DIMT1 specifically binds during the post-A1 stage of SSU processing to helix 45 of 18S rRNA, where it installs m26,6A modification at sites 1850 and 1851 in the mammalian ribosomal sequence. The installation of m26,6A at these sites in the SSU is highly conserved across the kingdoms of life.Additionally, knockout (KO) of DIMT1 is known to be lethal. However, the exact details of DIMT1 functions in 18S biogenesis and what function 18S m26,6A serves for ribosome activity are not fully understood. In this thesis, we delve into the science behind DIMT1 and describe the properties behind its operation in cell biology. Firstly, our high throughput sequencing experiments show that DIMT1 significantly impacts several transcripts' transcription and translation efficiency. These transcripts are associated with various Gene Ontology (GO) terms. In particular, we identified transcripts related to cell cycle regulation, translation, DNA damage response, cell adhesion/migration, and immune response pathways. We find that DIMT1's catalytic activity is non-essential for cell survival or ribosome biogenesis.Additionally, our cell line model for catalytically inactive DIMT1 displays only a minor effect on translation rates and the fidelity of internal ribosome entry, while catalysis is dispensable for ribosome biogenesis. Secondly, we find that the DIMT1's RNA binding ability plays a huge role in cell biology. Our RNA-binding deficient DIMT1 model demonstrates that without DIMT1's ability to bind to RNA, RNA biogenesis is impaired, and cell viability is lost. Additionally, DIMT1 RNA binding is essential for DIMT1's ability to phase separate and localize to the nucleolus, the primary site of rRNA processing. Finally, we also provide evidence of DIMT1-mediated m26,6A modification on a species of small RNAs. Together, our data expands on the role DIMT1 plays in ribosome processing and cell function and expands on the importance of ribosome biogenesis factors, the role of phase separation, and the diversity of factors that drive phase separation. Additionally, our data provide more context for perceiving DIMT1 as an oncogene and provides evidence to support targeting DIMT1 as a treatment for a variety of cancer, including multiple hematopoietic malignancies and gastric carcinomas in particular.

Subject Added Entry-Topical Term  

Biochemistry.

Subject Added Entry-Topical Term  

Biophysics.

Subject Added Entry-Topical Term  

Molecular biology.

Index Term-Uncontrolled  

DIMT1

Index Term-Uncontrolled  

Nucleolus

Index Term-Uncontrolled  

Phase Seperation

Index Term-Uncontrolled  

Ribosome

Index Term-Uncontrolled  

Ribosome biogenesis

Index Term-Uncontrolled  

RNA modification

Index Term-Uncontrolled  

Ribosomal RNA

Added Entry-Corporate Name  

University of Pennsylvania Biochemistry and Molecular Biophysics

Host Item Entry  

Dissertations Abstracts International. 84-12B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:643397