The cullin-RING ubiquitin ligase (CRL) family contains upwards of 240 ubiquitin ligases that regulate a broad range of cellular and organismal processes. Consistent with their critical roles in regulatory biology, CRLs have been intimately linked to human disease pathogenesis and therapy: mutations in CRL subunits underlie the development of several human cancers and CRL4CRBN has been implicated as the target of the anti- myeloma agent Thalomid. CRL pathways are regulated by multiple mechanisms, including dynamic cycles of CRL assembly/disassembly and post-translational modification of the cullin subunit by the ubiquitin-like protein Nedd8. CSN is a Nedd8 isopeptidase that regulates CRLs by removing the Nedd8 modification. Removal of Nedd8 from a CRL results in its deactivation and renders its substrate receptor susceptible to disassembly by the exchange factor, Cand1. Although the isopeptidase activity of CSN inhibits CRL activity, genetic studies indicate that CSN is a positive regulator of CRLs, which suggests that periodic deactivation and disassembly of CRLs is required to sustain CRL activity. Recently, the Nedd8 conjugation pathway has emerged as a drug target for cancer chemotherapy and the active site subunit of Csn5 has been implicated in sustaining tumorigenicity in a Myc-driven cancer model. Together, these data point to dynamic cycling of CRLs as being critical for cancer cell proliferation. The over-arching hypotheses that animate this project are that CSN plays a critical role in regulating the activity of CRL enzymes and architecture of the CRL network, and that perturbation of CSN activity is toxic to cancer cells. We plan to explore these topics in three Specific Aims.
In Aim 1 we will use quantitative multidimensional mass spectrometry to characterize the architecture and dynamics of the CRL proteome.
In Aim 2, we will characterize a novel non-enzymatic CRL-inhibitory activity of CSN.
In Aim 3, we will generate a CSN isopeptidase inhibitor to use as a research tool and to evaluate whether CSN is a promising target for chemotherapy of cancer.

Public Health Relevance

The CRL regulator NeddS is the target of an anti-cancer drug that is in clinical trials and a particular CRL is the target of the successful anti-myeloma drugs thalidomide and lenalidomide. Recent work suggests that the CRL regulator CSN is a promising drug target for therapy of cancers that are caused by oncogenic KRAS or over expression of MYC. The work proposed here aims to build a foundation of knowledge and reagents that will facilitate future efforts to target CSN for therapy of cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
4R01CA164803-04
Application #
8970688
Study Section
Membrane Biology and Protein Processing (MBPP)
Program Officer
Knowlton, John R
Project Start
2013-01-01
Project End
2017-12-31
Budget Start
2016-01-01
Budget End
2016-12-31
Support Year
4
Fiscal Year
2016
Total Cost
$294,954
Indirect Cost
$82,461
Name
California Institute of Technology
Department
Type
Schools of Arts and Sciences
DUNS #
009584210
City
Pasadena
State
CA
Country
United States
Zip Code
91125
Li, Jing; Zhang, Yaru; Da Silva Sil Dos Santos, Bruno et al. (2018) Epidithiodiketopiperazines Inhibit Protein Degradation by Targeting Proteasome Deubiquitinase Rpn11. Cell Chem Biol 25:1350-1358.e9
Chen, Allie Y; Adamek, Rebecca N; Dick, Benjamin L et al. (2018) Targeting Metalloenzymes for Therapeutic Intervention. Chem Rev :
Perez, Christian; Li, Jing; Parlati, Francesco et al. (2017) Correction to Discovery of an Inhibitor of the Proteasome Subunit Rpn11. J Med Chem 60:3217
Skrott, Zdenek; Mistrik, Martin; Andersen, Klaus Kaae et al. (2017) Alcohol-abuse drug disulfiram targets cancer via p97 segregase adaptor NPL4. Nature 552:194-199
Li, Jing; Yakushi, Tanya; Parlati, Francesco et al. (2017) Capzimin is a potent and specific inhibitor of proteasome isopeptidase Rpn11. Nat Chem Biol 13:486-493
Cohen, Seth M (2017) A Bioinorganic Approach to Fragment-Based Drug Discovery Targeting Metalloenzymes. Acc Chem Res 50:2007-2016
Lauinger, Linda; Li, Jing; Shostak, Anton et al. (2017) Thiolutin is a zinc chelator that inhibits the Rpn11 and other JAMM metalloproteases. Nat Chem Biol 13:709-714
Perez, Christian; Li, Jing; Parlati, Francesco et al. (2017) Discovery of an Inhibitor of the Proteasome Subunit Rpn11. J Med Chem 60:1343-1361
Mosadeghi, Ruzbeh; Reichermeier, Kurt M; Winkler, Martin et al. (2016) Structural and kinetic analysis of the COP9-Signalosome activation and the cullin-RING ubiquitin ligase deneddylation cycle. Elife 5:
Pulvino, Mary; Chen, Luojing; Oleksyn, David et al. (2015) Inhibition of COP9-signalosome (CSN) deneddylating activity and tumor growth of diffuse large B-cell lymphomas by doxycycline. Oncotarget 6:14796-813

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