PXD061234

PXD061234 is an original dataset announced via ProteomeXchange.

Title	Bulk delivery of a preassembled apical surface initiates epithelial lumen formation
Description	The creation of a microvilli-rich apical luminal domain is essential for epithelial tissue morphogenesis and is closely coordinated with the formation of the apical junctional complex (AJC). De novo lumenogenesis, in which epithelial cells establish apical identity by directing apical cargo to an apical membrane initiation site (AMIS), has been studied extensively. However, the mechanisms behind AMIS formation and its progression into a luminal precursor remain poorly understood. In this study, we employed super-resolution imaging, correlative light and electron microscopy, and time-resolved proximity proteomics to explore the spatial, temporal, and molecular processes involved in apical lumen initiation in MDCK-II cells. Interestingly, we discovered that, in both 2D and 3D cultures, the formation of the apical cell cortex begins with the fusion of large intracellular apical precursor organelles called vacuolar apical compartments (VACs) at developing cell-cell junctions. Our time-resolved proteomics and imaging analyses revealed a dynamic protein network that likely coordinates the exocytosis of VACs and lumen initiation with the formation and maturation of the AJC. Furthermore, we report that loss of the Crumbs complex proteins Pals1 or PatJ or inhibition of Rho/ROCK signaling impedes VAC exocytosis at the AMIS, resulting in severe defects in lumen morphogenesis. Overall, our findings define a molecular network for de novo cell polarization and highlight Pals1/PatJ as key regulators of apical domain initiation. We further propose that VACs represent a previously unrecognized transport carrier that plays a crucial role in the rapid establishment of apical domain identity.
HostingRepository	PRIDE
AnnounceDate	2026-06-08
AnnouncementXML	Submission_2026-06-08_08:46:42.383.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Eleanor Martin
SpeciesList	scientific name: Canis familiaris (Dog) (Canis lupus familiaris); NCBI TaxID: NEWT:9615;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive Plus

Revision	Datetime	Status	ChangeLog Entry
0	2025-02-26 14:09:53	ID requested
⏵ 1	2026-06-08 08:46:42	announced

Dataset with its publication pending

submitter keyword: Epithelial polarity

Gunnar Dittmar
contact affiliation	Group Leader, Proteomics of Cellular Signaling, Luxembourg Institute of Health
contact email	gunnar.dittmar@lih.lu
lab head
Eleanor Martin
contact affiliation	NTU (former)
contact email	eleanor.martin@ntu.edu.sg
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/2026/06/PXD061234

PRIDE project URI

• PRIDE
  1. PXD061234
     1. Label: PRIDE project
     2. Name: Bulk delivery of a preassembled apical surface initiates epithelial lumen formation