Completed Genetics & Molecular Biology Cells, Biochemistry & Physiology

Establishing the basis for selectivity in the SUMO spray

Funder Wellcome Charity-funded
Recipient organisation University of Dundee
Funding £1.9M
Period Feb 2020 — Feb 2025

In plain English

AI plain-English summary

Every cell in the human body tags thousands of proteins with a small molecular marker called SUMO, and a class of enzymes called PIAS E3 ligases orchestrate this process by spraying SUMO onto entire groups of proteins at once. The problem is that no one understands how these enzymes pick which protein complexes to modify, or why that selectivity matters for keeping a cell in its stem-cell state. This project aims to crack that selection mechanism. The researchers will use a drug to shut down SUMO tagging globally, and deploy CRISPR and nanobody tools to remove SUMO only at specific genes or on specific protein machines. They will then track what happens to the cell’s identity, its DNA packaging, and its gene activity. They also plan to solve the first-ever 3D structure of a PIAS enzyme caught in the act of modifying a DNA-bound protein complex. This is fundamental science. There is no immediate medical or industrial application. But understanding how cells control which proteins get SUMO-tagged—and how that control goes wrong in diseases such as cancer—could eventually point toward new ways to intervene. Past work on similar molecular switches has led to drugs that now treat leukaemia and other conditions.

View original technical description
Specificity in the SUMO system appears to be achieved by modification of large groups of proteins by a PIAS E3 ligase mediated SUMO spray. Our aim is to define the mechanism by which PIAS E3 ligases select multiprotein complexes for modification. Proteomic identification of sites of SUMO modification and SUMO ChIPSeq analysis provide evidence that the SUMO spray functions in human induced pluripotent stem cells. Our objectives are to establish the role of the “SUMO spray” in maintaining pluripotency. We will deplete SUMO globally using the ML792 E1 inhibitor and will deplete SUMO locally at specific genomic loci using Cas9-SUMO protease fusions and at multiprotein complexes using nanobody-SUMO protease fusions. We will follow cell fate, changes in histone marks, chromatin accessibility, transcriptional output and the stability of multiprotein complexes. PIAS proteins can be recruited to substrates via DNA, SUMO and specific protein interactions. We will use structural, biochemical and single molecule approaches to describe PIAS mediated SUMO modification. Our ultimate goal is the structural determination of a ternary complex of DNA bound substrate, PIAS protein and SUMO loaded E2. This would be a first in its class structure and would reveal the mechanism of SUMO spray mediated substrate modification.

View the original record at the funder ↗

Researchers

Ronald Hay (EPMC Awardee)

Related Research

Grants with similar aims, by meaning.

Determining the mechanism of SUMO dependent transcriptional repression in human stem cells
Protein SUMOylation and transcriptional control in a dynamic 3D chromatin environment
Studying the role of the Sin3A/HDAC1 complex in DNA replication and Mitosis using novel therapeutic approaches
Structure and function of the SUMO specific protease SENP7
Transcriptional control mechanisms of immediate-early genes: the convergence of phosphorylation, acetylation, parylation and sumoylation regulatory events

Original classification

Investigator Award in Science

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