PXD055870-1

PXD055870 is an original dataset announced via ProteomeXchange.

Title	Identification of post translational modifications of human Topoiosmerase 1 in the presence of camptothecin and CHK1 inhibitor SCH900776.
Description	Topisomerase 1 (TOP1), an essential enzyme in humans, plays a critical role in relaxation of DNA supercoils during replication and transcription. The TOP1 reaction cycle involves an obligate TOP1-DNA covalent complex intermediate (TOP1cc), which is stabilized by TOP1 poisons like camptothecin. While cellular responses to potentially genotoxic TOP1ccs are widely studied, the regulation of TOP1 catalytic cycle itself inside the cell in poorly understood. In the current study, we have demonstrated a regulatory role of the master checkpoint kinase CHK1 in regulating the TOP1 catalytic cycle inside cells. We performed an in silico prediction of CHK1 cognate sites on TOP1. In order to validate the same, we isolated catalytically engaged TOP1 from human genomic DNA, and performed mass spectrometric analysis. Our analysis revealed one previously unreported putative CHK1 cognate site to be phosphorylated on TOP1 inside cells. We further employed site directed mutagenesis, molecular and cellular assays to establish the role played by CHK1 in regulating TOP1 catalysis.
HostingRepository	PRIDE
AnnounceDate	2026-03-16
AnnouncementXML	Submission_2026-03-16_08:45:35.815.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Birija Patro
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: NEWT:9606;
ModificationList	phosphorylated residue; acetylated residue; monohydroxylated residue; iodoacetamide derivatized residue
Instrument	Orbitrap Eclipse

Revision	Datetime	Status	ChangeLog Entry
0	2024-09-15 02:44:11	ID requested
⏵ 1	2026-03-16 08:45:36	announced

Dataset with its publication pending

submitter keyword: Topoisomerase 1, MK-8776, CHK1, SCH900776, camptothecin

Dr. Birija Sankar Patro
contact affiliation	Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
contact email	bisank@barc.gov.in
lab head
Birija Patro
contact affiliation	Head, Bio-Organic Division Mod. Lab, Bio-Organic Division, Trombay, Mumbai-400085
contact email	bisank@barc.gov.in
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/2026/03/PXD055870

PRIDE project URI

• PRIDE
  1. PXD055870
     1. Label: PRIDE project
     2. Name: Identification of post translational modifications of human Topoiosmerase 1 in the presence of camptothecin and CHK1 inhibitor SCH900776.