PXD059437

PXD059437 is an original dataset announced via ProteomeXchange.

Title	LC-MS/MS to identify WT, 8NQ, N91/104/309/322Q and N91/104/309/322 B7H3 interaction
Description	The specific N-glycans of glycoproteins play key roles in regulating protein localization, stability and activity. B7H3, an immune checkpoint molecule, is a highly N-glycosylated membrane protein. However, the key glycosylated asparagine (Asn) residues that mediate the function of the B7H3 protein are still unclear. Here we identify that among the four pairs of putative N-glycosylation sites, N-glycans attached to asparagine residues N91/309 and N104/322 are required for proper B7H3 protein folding in the endoplasmic reticulum (ER) and intracellular trafficking to the cell surface membrane. We demonstrate that mutations in these two pairs of N-glycosylation sites induce ER accumulation of B7H3 by blocking its ER-to-Golgi translocation and subsequently promote its degradation via the endoplasmic reticulum-associated protein degradation (ERAD) pathway. Additional evidence suggests that N-glycosylation at N91/309 and N104/322 of B7H3 is essential for its inhibition of T-cell proliferation and activation. More importantly, a monoclonal antibody, Ab-82, targeting B7H3 glycosylated at N91/309 and N104/322 is developed, which exhibits the ability to elicit cytotoxic T lymphocyte-mediated antitumor immunity via B7H3 internalization and degradation. Together, these findings provide novel insights into the functional significance of B7H3 glycosylation and offer a rationale for targeting glycosylated B7H3 as a potential strategy for immunotherapy. To compare the binding partners of WT, 8NQ, and N91/104/309/322Q and N91/104/309/322 B7H3, these B7H3 constructs were stably expressed in MDA-MB-231 cell lines. The B7H3 protein was purified using affinity capture purification, followed by immunoprecipitation and mass spectrometry to identify the B7H3 interactome. Ingenuity Pathway Analysis based on these mass spectrometry data showed that the binding to components of the endoplasmic reticulum-associated degradation (ERAD) pathway was greater for the N91/104/309/322Q and 8NQ mutants than for the N91/104/309/322 mutant and WT B7H3.
HostingRepository	PRIDE
AnnounceDate	2025-03-27
AnnouncementXML	Submission_2025-03-27_08:30:07.526.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	xiaoyu yang
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	No PTMs are included in the dataset
Instrument	LTQ

Revision	Datetime	Status	ChangeLog Entry
0	2025-01-04 05:25:04	ID requested
⏵ 1	2025-03-27 08:30:07	announced

Dataset with its publication pending

submitter keyword: LC-MS/MS, B7H3

Rong Deng
contact affiliation	State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou 510060, China (lab head)
contact email	dengrong@sysucc.org.cn
lab head
xiaoyu yang
contact affiliation	Sun Yat-sen University Cancer Center
contact email	yangxy2@sysucc.org.cn
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/2025/03/PXD059437

PRIDE project URI

• PRIDE
  1. PXD059437
     1. Label: PRIDE project
     2. Name: LC-MS/MS to identify WT, 8NQ, N91/104/309/322Q and N91/104/309/322 B7H3 interaction