Roles for transcription factor RPRD proteins in mRNA synthesis and R-loop formation

Ceylan, Hurmuz (2023). Roles for transcription factor RPRD proteins in mRNA synthesis and R-loop formation. University of Birmingham. Ph.D.

Preview

Ceylan2023PhD.pdf
Text - Accepted Version
Available under License All rights reserved.
Download (6MB) | Preview

Abstract

Transcription is a process of copying DNA into RNA. The transcription pattern determines the identity of the cell, and transcriptional regulation plays an essential role in this process. The primary protein driving this process is RNA polymerase II (RNAPII), which interacts with other regulatory proteins via its C-terminal domain (CTD). The RPRD1A, RPRD1B, and RPRD2 proteins have a CTD-interacting domain (CID), although their specific roles and functions in transcriptional processes remain inadequately understood. My research demonstrates that depletion of RPRD1A, RPRD1B, and RPRD2 leads to an increase in nascent RNA levels, while their overexpression has the opposite effect. However, these proteins did not significantly affect total RNA levels. I found that deregulation of RPRD2 affects the stability of RNAs inversely with RPRD2 levels. Furthermore, RPRD protein levels correlated with the level of R-loops, and increased R-loops in RPRD up-regulated cells induced the DNA damage response. As a byproduct of transcription, the alteration in transcription rate and the ensuing DNA damage caused by the accumulation of R-loops lead to the inhibition of cell cycle progression. I analyzed the glioma dataset and found that higher expression of RPRD1B proteins increased glioma aggressiveness, while low expression of RPRD1A and RPRD2 decreased patient survival times. My results suggest that RPRD proteins negatively impact newly transcribed RNA by interacting and recruiting other transcription factors to the site. As a response, cells change the stability of existing mRNAs in order to maintain cellular homeostasis. However, cells with transcription control problems may not respond appropriately to metabolic conditions, internal or external signals, or stress, despite adjusted mRNA levels. Accumulated errors could lead to the transformation of healthy cells into cancerous ones.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):