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PXD073461

PXD073461 is an original dataset announced via ProteomeXchange.

Dataset Summary
TitleCharacterization of Protein Phosphatase 1b substrate specificity
DescriptionPhosphoprotein phosphatase 1 (PP1) is a heterodimeric holoenzyme consisting of a catalytic subunit (PP1c) and one of over 200 regulatory subunits (PP1R). The interaction between catalytic and regulatory subunits is mediated by short linear motifs (SLiMs). The human genome encodes four highly conserved PP1c isoforms, PP1ca, PP1cb, and splice variants PP1cc1 and PP1cc2. Using affinity purification mass spectrometry (AP-MS), we identify PP1c isoform-specific interactors and confirm that myosin phosphatase N-terminal element (MyPhoNE) motif-containing PP1R are significantly enriched in binding to the PP1cb compared to the PP1ca and PP1cc isoforms. To uncover the key binding determinants of PP1cb binding to MyPhoNE-containing PP1Rs, we created chimeric mutants of PP1cb and PP1cc. We employed CRISPR-Cas9-mediated editing of the PP1cb locus to generate a Thr197Gln mutant that mimics the amino acid found in PP1cc. We find that the Thr197 residue, as well as carboxyl-terminal residues of PP1cb, coordinate binding to MyPhoNE-PP1Rs. Additionally, quantitative phosphoproteomics of the homozygous knock-in PP1cb Thr197Gln cells identifies a phosphorylation site in the activation loop of Polo-like kinase 1 (PLK1) as a potential PP1cb substrate. We validate this finding by immunofluorescence and add to the current understanding of the critical role of the PP1cb-MYPT1 holoenzyme in controlling PLK1 activity in early mitosis.
HostingRepositoryMassIVE
AnnounceDate2026-08-20
AnnouncementXMLSubmission_2026-08-20_14:06:46.095.xml
DigitalObjectIdentifier
ReviewLevelNon peer-reviewed dataset
DatasetOriginOriginal dataset
RepositorySupportSupported dataset by repository
PrimarySubmitterArminja Nadine Kettenbach
SpeciesList scientific name: Homo sapiens; common name: human; NCBI TaxID: 9606;
ModificationListPhospho
InstrumentOrbitrap Fusion; Orbitrap Fusion Lumos; Q Exactive Plus
Dataset History
RevisionDatetimeStatusChangeLog Entry
02026-01-23 09:02:07ID requested
12026-08-20 14:06:46announced
Publication List
no publication
Keyword List
submitter keyword: phosphoprotein phosphatase 1 (PP1), substrate specificity, MyPhoNE motif, protein chimera, phosphorylation, phosphoproteomics, mitosis, DatasetType:Proteomics
Contact List
Arminja Kettenbach
contact affiliationThe Geisel School of Medicine at Dartmouth
contact emailarminja.n.kettenbach@dartmouth.edu
lab head
Arminja Nadine Kettenbach
contact affiliationDartmouth
contact emailArminja.N.Kettenbach@Dartmouth.edu
dataset submitter
Full Dataset Link List
MassIVE dataset URI
Dataset FTP location
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