PXD036103-1

PXD036103 is an original dataset announced via ProteomeXchange.

Title	Function of ERphagy receptors is regulated via phosphorylation-dependent ubiquitination pathways
Description	Selective autophagy of the ER (ERphagy) is an important regulator of ER remodeling and critical to maintain cellular homeostasis upon environmental changes. ERphagy receptors link the ER with autophagic membrane thus regulating ERphagy flux. We recently showed that members of the FAM134 family play overlapping and distinct roles during stress-induced ERphagy. Yet the mechanisms on how they are activated remain largely unknown. In this study we analyzed mTOR-mediated dynamic phosphorylation of FAM134 as a trigger of FAM134-driven ERphagy. An unbiased screen of kinase inhibitors revealed CK2 to be essential for FAM134B- and FAM134C-driven ERphagy upon mTOR inhibition. Identified dynamic phosphorylation sites on FAM134C in cells were fitting with predicted CK2 targeting sites, indicating a direct regulatory role of CK2 in FAM134-driven ERphagy. Using super-resolution microscopy, we showed that activity of CK2 is essential for the formation of high-density clusters of FAM134B and FAM134C. Consistently, FAM134B and FAM134C proteins carrying point mutations of selected Serin residues, within their reticulon homology domain, are unable to form high-density clusters. In addition, we provide evidence that the ubiquitination machinery is required for ERphagy and that FAM134B and FAM134C clustering is activated by phospho-dependent ubiquitination. Treatment with CK2 inhibitor SGC-CK2-1 prevents Torin1-induced ERphagy flux as well as ubiquitination of FAM134 proteins and consistently, treatment with E1 inhibitor suppresses Torin1-induced ERphagy flux. Therefore, we propose CK2 dependent phosphorylation of ERphagy receptors precedes ubiquitin-dependent ERphagy flux activation.
HostingRepository	PRIDE
AnnounceDate	2022-08-17
AnnouncementXML	Submission_2022-08-17_02:08:38.232.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Petra Beli
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	phosphorylated residue; iodoacetamide derivatized residue
Instrument	Q Exactive Plus

Revision	Datetime	Status	ChangeLog Entry
0	2022-08-16 13:43:18	ID requested
⏵ 1	2022-08-17 02:08:38	announced

Dataset with its publication pending

submitter keyword: endoplasmic reticulum, selective autophagy, FAM134B, FAM134C, lysosomal degradation, ER remodeling, ER fragmentation, ER homeostasis, stress response, ATM, ATR, CHEK1, CK2, mTOR, ubiquitination

Petra Beli
contact affiliation	Institute of Molecular Biology, D-55118 Mainz, Germany
contact email	p.beli@imb-mainz.de
lab head
Petra Beli
contact affiliation	Institute of Molecular Biology (IMB), Mainz, Germany
contact email	p.beli@imb-mainz.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD036103
     1. Label: PRIDE project
     2. Name: Function of ERphagy receptors is regulated via phosphorylation-dependent ubiquitination pathways