PXD063667

PXD063667 is an original dataset announced via ProteomeXchange.

Title	Microtubule anchoring and coupling of CD20 to the RhoA/Rock1 pathway (PKCdelta KO SILAC phosphoproteomics)
Description	CD20 is a B cell-specific four-helix transmembrane protein and a prominent target of successful therapeutic anti-CD20 antibodies such as rituximab (RTX) and GA101. We have recently described that CD20 is localized within a membrane nanocluster harboring the IgD class B cell antigen receptor (IgD-BCR) where it functions as a gatekeeper for the resting state of naïve human B lymphocytes. Loss of CD20 results in the remodeling of the IgD-BCR nanocluster and B cell activation. How CD20 exerts its gatekeeper function was not known so far. Using the Ramos B cell system and human peripheral blood B cells, we show here that another B cell gatekeeper, the serine/threonine kinase PKCδ, constitutively phosphorylates specific serine residues at the N- and C-terminal cytosolic tails of CD20. The phosphorylated CD20 becomes a target for 14-3-3 adaptor proteins that link CD20 to the RhoA GDP/GTP exchange factor GEF-H1 (ARHG2). The autoinhibited form of GEF-H1 couples CD20 to the microtubule network that controls the stability of the IgD-BCR nanocluster on resting B cells. Binding of anti-CD20 antibodies results in microtubule disassembly and the replacement of the GEF-H1/CD20 complex by a RhoA-GTP/ROCK1/CD20 complex, which drives actomyosin assembly and translocation of CD20 and the coreceptor CD19 to the IgM-BCR. The effect of anti-CD20 antibodies can be mimicked by exposing B cells to microtubule destabilizing drugs such as nocodazole (Noc) whereas microtubule stabilizing drugs such as Taxol (Tax) prevent the IgD-BCR nanocluster dissociation a finding that may alter therapeutic protocols of anti-CD20 treatments. Taken together, our study suggests that CD20 not only maintains the resting state, but also orchestrates the microtubule-actin switch in active B lymphocytes.
HostingRepository	PRIDE
AnnounceDate	2026-04-17
AnnouncementXML	Submission_2026-04-17_08:47:18.253.xml
DigitalObjectIdentifier	https://doi.org/10.6019/PXD063667
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Julian Bender
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: NEWT:9606;
ModificationList	iodoacetamide derivatized residue
Instrument	Q Exactive Plus

Revision	Datetime	Status	ChangeLog Entry
0	2025-05-06 09:49:07	ID requested
⏵ 1	2026-04-17 08:47:18	announced

10.6019/PXD063667;

10.1038/S44318-026-00781-5;

submitter keyword: microtubule network, PKCδ, RhoA/Rock1 pathway, mass spectrometry, SILAC,B lymphocyte

CD20, phosphoproteomics, microtubule-to-actin switch

Bettina Warscheid
contact affiliation	Chair of Biochemistry II, Theodor Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
contact email	bettina.warscheid@uni-wuerzburg.de
lab head
Julian Bender
contact affiliation	University of Wuerzburg Chair of Biochemistry II Am Hubland 97074 Würzburg
contact email	julian.bender@uni-wuerzburg.de
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/2026/04/PXD063667

PRIDE project URI

• PRIDE
  1. PXD063667
     1. Label: PRIDE project
     2. Name: Microtubule anchoring and coupling of CD20 to the RhoA/Rock1 pathway (PKCdelta KO SILAC phosphoproteomics)