PXD018717-2

PXD018717 is an original dataset announced via ProteomeXchange.

Title	An evolutionarily distinct chaperone is required for 20S proteasome α-ring assembly in Arabidopsis
Description	26S proteasomes direct the degradation of many short-lived regulatory proteins and dysfunctional polypeptides, and thus are essential effectors of eukaryotic proteostasis. Proteolysis by this multi-subunit complex occurs inside a barrel-shaped 20S core protease (CP) whose quaternary structure is conserved across all domains of life, and comprises four co-axially stacked heptameric rings formed by structurally related α- and β-subunits in an αββα configuration. CP biogenesis typically begins with the assembly of the α-rings, which then serve as templates for β-subunit integration, three of which present a peptidase active site within the central β-ring chamber. In eukaryotes, α-ring assembly is partially mediated by two hetero-dimeric chaperones, termed Pba1-Pba2 and Pba3-Pba4 in yeast (or PAC1-PAC2 and PAC3-PAC4 in mammals). Pba1-Pba2 initially promotes orderly recruitment of the α-subunits through interactions between their C-terminal HbYX/HbF motifs and shallow pockets at the α5-α6 and α6-α7 interfaces. Here, we identify PBAC5 as a fifth α-ring assembly chaperone in Arabidopsis that directly associates with the Pba1 homolog PBAC1 to form a trimeric PBAC5-PBAC1-PBAC2 complex that can functionally replace the yeast Pba1-Pba2 pair. PBAC5 contains a HbYX motif that likely docks with the pocket formed between the α4 and α5 subunits during α-ring formation. Arabidopsis missing PBAC5, PBAC1, and/or PBAC2 are hypersensitive to proteotoxic, salt and osmotic stress, and display proteasome assembly defects, consistent with a role in CP assembly. Remarkably, while PBAC5 is evolutionarily conserved in plants, it is also present in other kingdoms, with homologs evident in a limited array of fungal, metazoan, and oomycete species.
HostingRepository	PRIDE
AnnounceDate	2024-10-22
AnnouncementXML	Submission_2024-10-22_05:03:59.022.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Fionn McLoughlin
SpeciesList	scientific name: Arabidopsis thaliana (Mouse-ear cress); NCBI TaxID: 3702;
ModificationList	monohydroxylated residue; acetylated residue; iodoacetamide derivatized residue
Instrument	Q Exactive

Revision	Datetime	Status	ChangeLog Entry
0	2020-04-21 09:05:29	ID requested
1	2020-05-18 05:24:12	announced
⏵ 2	2024-10-22 05:03:59	announced	2024-10-22: Updated project metadata.

Dataset with its publication pending

submitter keyword: Arabidopsis,Proteasome assembly

Richard David Vierstra
contact affiliation	Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
contact email	rdvierstra@wustl.edu
lab head
Fionn McLoughlin
contact affiliation	Washington University in Saint Louis
contact email	fmcloughlin@wustl.edu
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/2020/05/PXD018717

PRIDE project URI

• PRIDE
  1. PXD018717
     1. Label: PRIDE project
     2. Name: An evolutionarily distinct chaperone is required for 20S proteasome α-ring assembly in Arabidopsis