Deconstruction of complex crosslinking damage

Introduction

Cells are constantly challenged by complex crosslinking damage, which is caused not only by endogenous metabolites, such as reactive aldehydes, but also by various exogenous sources. While crosslinking damage to DNA has been studied extensively, almost all reactive agents act pleiotropically and also damage RNA and proteins.

Complexity of Damage

However, due to the complexity of the damage, it is difficult to determine which components of the damage are responsible for specific cellular outcomes. Therefore, it is unknown how crosslinking damage to RNA and proteins affects cellular homeostasis and how it is detected and resolved.

Proposed Approach

Here, I propose to exploit novel experimental model systems that deconstruct complex crosslinking damage into distinct toxic components. I will combine metabolic labelling with photoactivatable-crosslinking approaches to mimic aldehyde-induced RNA or protein damage in the absence of DNA damage.

Methodology

We will combine these model systems with genetic and proteomic approaches to define the molecular mechanisms that detect and resolve:

1. RNA-protein crosslinks
2. Protein-protein crosslinks

To this end, we will capitalize on preliminary work indicating the existence of an entirely uncharacterized translation-coupled quality control mechanism that ubiquitylates and degrades proteins crosslinked to mRNA.

Objectives

Ultimately, I will build on these mechanistic insights to explore the physiological role of RNA and protein damage in:

1. The response to endogenous formaldehyde generated during cellular differentiation
2. The mechanisms of action of chemotherapeutic crosslinkers

Significance of the Work

My work will provide a comprehensive view on how complex crosslinking damage affects cellular homeostasis and will challenge the current paradigm that DNA damage is solely responsible for the cytotoxicity of crosslinking agents.

Implications

As such, my work will address a major blind spot in the fields of cellular quality control and genome stability with wide-ranging implications for cancer therapy and ageing.