SUMO unchained: molecular mechanisms of ubiquitin-like signal transduction in cell cycle progression

Abstract

All living organisms are made out of cells, which serve as the fundamental units of life. Protein molecules, comprised of amino acids, carry out diverse functions across various cellular compartments. Proteins are tightly controlled in their synthesis, folding, localization and degradation to ensure proper functioning. Dysregulation of protein control mechanisms within the cell can lead to cellular dysfunction, disease or eventually cell death. Post-translational modifications (PTMs) are the addition of a chemical group to an existing protein to regulate its function, localization, stability or interaction. In this thesis we will dive deeper into PTMs SUMO and ubiquitin, with the aim to understand the biochemistry of these proteins in different aspects of cellular function and human pathophysiology. An interesting aspect of the conjugation process lies in its reversibility, which is governed by specific proteases known as SENPs in the case of SUMO. However, only SENP6 and SENP7 have the ability to depolymerize SUMO2/3 chains by an insertion in their conserved catalytic domains. We delve into the promising horizon that lies ahead of a small yet profoundly impactful post-translational modifying protein. Despite its modest size, this protein wields a significant influence on fundamental cellular processes