PXD038123

PXD038123 is an original dataset announced via ProteomeXchange.

Title	CAMK2D recruits RNF8-MAD2 complex to RNA splicing proteins for mitotic checkpoint activation in GBM
Description	Glioblastoma (GBM) is a lethal brain tumor with remarkable intra-tumoral heterogeneity and therapeutic resistance which is linked to glioma stem cell (GSC). GSC contains unstable genome and elevated genomic instability could impair GSC self-renewal and tumorigenicity. In addition, GSC displays great dependency on BubR1, which is a key regulator of spindle assembly checkpoint (SAC) for proper chromosomal segregation. SAC prevents precocious anaphase progression in the presence of unattached kinetochores to ensure genomic integrity. To date, the regulation of SAC in GBM is still poorly understood and whether SAC could be exploited as a therapeutic target for GBM remains unknown. In our study, we revealed a previously unrecognized role of RNF8 in promoting SAC activation in GBM. GBM preferentially downregulates RNF8 in part by promoter methylation and low RNF8 expression correlates with inferior patient prognosis. Overexpression (OE) of wild-type RNF8 but not FHA and RING mutants significantly reduces GSC self-renewal, proliferation and tumorigenicity, and increases genomic instability. Mechanistically, the RING domain associates with the closed conformer of Mad2 (c-Mad2) and c-Mad2 exists as a complex with p31comet. CAMK2D binds transiently to the FHA domain via threonine 287 and this leads to RNF8 phosphorylation at serine 157. Furthermore, CAMK2D functions to recruit RNF8 to RNA splicing proteins to promote SAC activation independently of its enzymatic activity. To indirectly target RNF8-associated SAC in GBM, we exploited Connectivity Map (CMAP) and found that PLK1 inhibitor (PLK1i) could mimic RNF8-OE gene signature. Combination of PLK1i and proteostatic stressor leads to synergistic killing in GSCs. Collectively, our study unveiled an unconventional role of RNF8 in SAC regulation, dissected its molecular mechanisms and highlights the biological complexity of E3 ubiqtuitin ligases.
HostingRepository	jPOST
AnnounceDate	2023-07-21
AnnouncementXML	Submission_2023-07-21_01:54:42.008.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Radoslaw Sobota
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	S-carboxamidomethyl-L-cysteine; alpha-amino acetylated residue; TMT6plex reporter+balance reagent N-acylated residue; TMT6plex reporter+balance reagent acylated N-terminal; L-methionine sulfoxide; deamidated L-glutamine; deamidated L-asparagine
Instrument	Orbitrap Fusion

Revision	Datetime	Status	ChangeLog Entry
0	2022-11-13 19:09:51	ID requested
1	2023-07-20 20:32:16	announced
⏵ 2	2023-07-21 01:54:42	announced	2023-07-21: Updated PubMed.

Chuah YH, Tay EXY, Grinchuk OV, Yoon J, Feng J, Kannan S, Robert M, Jakhar R, Liang Y, Lee BWL, Wang LC, Lim YT, Zhao T, Sobota RM, Lu G, Low BC, Crasta KC, Verma CS, Lin Z, Ong DST, CAMK2D serves as a molecular scaffold for RNF8-MAD2 complex to induce mitotic checkpoint in glioma. Cell Death Differ, 30(8):1973-1987(2023) [pubmed]

submitter keyword: RNF8, interactome, BioID, mass spectrometry, glioblastoma

Sek Tong Derrick, Ong
lab head
Radoslaw Sobota
contact affiliation	IMCB A-STAR Singapore
dataset submitter

jPOST dataset URI

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