PXD046269-1

PXD046269 is an original dataset announced via ProteomeXchange.

Title	An integrated chemoproteomic and screening platform identifies a functional and ligandable non-catalytic cysteine in caspase-2
Description	Caspases are a highly conserved family of cysteine-aspartyl proteases known for their essential roles in regulating apoptosis, inflammation, cell differentiation and proliferation. Complementary to genetic approaches, small molecule inhibitors have emerged as useful tools for modulating caspase activity. Achieving high selectivity remains a central challenge for caspase-directed inhibitor development efforts, due to the high sequence and structure homology of all twelve human caspases. Here, using a chemoproteomic approach, we first identify a highly reactive non-catalytic cysteine that is unique to caspase-2. By combining both gel-based activity-based protein profiling (ABPP) and a TEV activation assay, we then identify covalent lead compounds that react preferentially with this cysteine and afford a complete blockade of caspase-2 activity. Inhibitory activity is restricted to the zymogen or precursor form of monomeric caspase-2, with compound treatment blocking intramolecular caspase interactions. Focused medicinal chemistry combined with chemoproteomic target engagement analysis in lysates and in cells yielded both caspase-2 selective and promiscuous caspase inhibitors, together with structurally matched inactive control compounds. Application of this focused set of tool compounds to stratify caspase contributions to activation of intrinsic apoptosis indicate likely compensatory caspase-9 activity driving etoposide-mediated cell death in the context of caspase-2 inactivation. More broadly, our study highlights the utility of targeting non-conserved and non-catalytic cysteine residues for achieving improved selectivity profiles for highly homologous families of enzymes.
HostingRepository	PRIDE
AnnounceDate	2025-01-14
AnnouncementXML	Submission_2025-01-14_13:44:38.689.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Jose Castellon
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	No PTMs are included in the dataset
Instrument	Orbitrap Eclipse

Revision	Datetime	Status	ChangeLog Entry
0	2023-10-20 12:10:30	ID requested
⏵ 1	2025-01-14 13:44:39	announced

10.1021/JACS.3C12240;

submitter keyword: FAIMS, isoTOP,LC-MSMS

Keriann Marie Backus
contact affiliation	Biological Chemistry, Chemistry and Biochemistry, UCLA,Los Angeles, California, USA
contact email	KBackus@mednet.ucla.edu
lab head
Jose Castellon
contact affiliation	UCLA
contact email	joseomar805@gmail.com
dataset submitter

Dataset FTP location NOTE: Most web browsers have now discontinued native support for FTP access within the browser window. But you can usually install another FTP app (we recommend FileZilla) and configure your browser to launch the external application when you click on this FTP link. Or otherwise, launch an app that supports FTP (like FileZilla) and use this address: ftp://ftp.pride.ebi.ac.uk/pride/data/archive/2025/01/PXD046269

PRIDE project URI

• PRIDE
  1. PXD046269
     1. Label: PRIDE project
     2. Name: An integrated chemoproteomic and screening platform identifies a functional and ligandable non-catalytic cysteine in caspase-2