Our long-range goals are to discover novel therapeutic strategies that advance treatment of cancer by targeting the ubiquitin-proteasome system, which is the major cellular pathway for selective degradation of proteins. Recently, we developed a new high-throughput screening assay to identify small molecule antagonists or agonists that target the catalytic activity of the Cullin-RING E3 ubiquitin ligases (CRL), which direct numerous protein substrates for degradation by the 26S proteasome. Our new technology is based on fluorescence (Frster) resonance energy transfer (FRET). It detects FRET signals that are produced by ligation of two fluorescently labeled ubiquitin (Ub) molecules, a reaction driven by CRL's core ligase complex. This assay has already been adapted for use on a robotic system to screen a large collection of small molecules, resulting in identification of a group of inhibitors with cytotoxic activity against tumor cells. Using the established methods, this project will carry out additional screens and identify a large set of small molecule modulators. We will subject these hits to a variety of biochemical, biophysical and cell-based assays to remove false positives and to classify them into distinct classes of inhibitors. Cheminformatics, structural biology, and medicinal chemical approaches will follow to refine such small molecules to increase their targeting potency. It is hopeful that this project will lead to discovery of small molecules with `drug-like' properties capable of selectively killing cancer cells.

Public Health Relevance

The goal of this project is to discover small molecule probes that modulate the catalytic activity of the Cullin- RING E3 ubiquitin ligases, which direct numerous protein substrates for degradation by the 26S proteasome. To this end we have employed fluorescence (Frster) resonance energy transfer technology and developed a powerful platform that has led to identification of inhibitory compounds with cytotoxic activity against tumor cells. We propose to use this platform to identify additional hit compounds and to perform hit-to-lead studies that will produce molecules of ?drug-like? properties with significant anti-cancer therapeutic potentials.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM122751-02
Application #
9454528
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Fabian, Miles
Project Start
2017-04-01
Project End
2020-03-31
Budget Start
2018-04-01
Budget End
2019-03-31
Support Year
2
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Icahn School of Medicine at Mount Sinai
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029