PXD028527

PXD028527 is an original dataset announced via ProteomeXchange.

Title	The Paulinella chromatophore N-terminome
Description	The cercozoan amoeba Paulinella chromatophora contains photosynthetic organelles - termed chromatophores - that evolved from a cyanobacterium ~100 million years ago, independently from plastids in plants and algae. Despite its more recent origin, at least one third of the chromatophore proteome consists of nucleus-encoded proteins that are imported by an unknown mechanism across the chromatophore double envelope membranes. Chromatophore-targeted proteins fall into two classes. Proteins exceeding 250 amino acids carry a conserved N-terminal sequence extension, termed the ‘chromatophore transit peptide’ (crTP), that is presumably involved in guiding these proteins into the chromatophore. Short imported proteins do not carry discernable targeting signals. To explore whether the import of protein is accompanied by their N-terminal processing, here we used a mass spectrometry-based approach to determine protein N-termini in Paulinella chromatophora and identified N-termini of 208 chromatophore-localized proteins. Our study revealed extensive N-terminal modifications by acetylation and proteolytic processing in both, the nucleus and chromatophore-encoded fraction of the chromatophore proteome. Mature N-termini of 37 crTP-carrying proteins were identified, of which 30 were cleaved in a common processing region. Our results imply that the crTP mediates trafficking through the Golgi, is bipartite and surprisingly only the N-terminal third (‘part 1’) becomes cleaved upon import, whereas the rest (‘part 2’) remains at the mature proteins. In contrast, short imported proteins remain largely unprocessed. Finally, this work sheds light on N-terminal processing of proteins encoded in an evolutionary-early-stage photosynthetic organelle and suggests host-derived post-translationally acting factors involved in dynamic regulation of the chromatophore-encoded chromatophore proteome.
HostingRepository	PRIDE
AnnounceDate	2023-11-14
AnnouncementXML	Submission_2023-11-14_07:45:33.933.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Pitter Huesgen
SpeciesList	scientific name: Arabidopsis thaliana (Mouse-ear cress); NCBI TaxID: 3702;
ModificationList	No PTMs are included in the dataset
Instrument	maXis

Revision	Datetime	Status	ChangeLog Entry
0	2021-09-16 06:41:32	ID requested
1	2023-04-06 06:32:26	announced
⏵ 2	2023-11-14 07:45:38	announced	2023-11-14: Updated project metadata.

Oberleitner L, Perrar A, Macorano L, Huesgen PF, Nowack ECM, A bipartite chromatophore transit peptide and N-terminal protein processing in the Paulinella chromatophore. Plant Physiol, 189(1):152-164(2022) [pubmed]

submitter keyword: protein import,chromatophore, Paulinella chromatophore

Pitter Huesgen
contact affiliation	ZEA-3 Analytics, Forschungszentrum Juelich
contact email	p.huesgen@fz-juelich.de
lab head
Pitter Huesgen
contact affiliation	University of Freiburg
contact email	p.huesgen@fz-juelich.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/2023/04/PXD028527

PRIDE project URI

• PRIDE
  1. PXD028527
     1. Label: PRIDE project
     2. Name: The Paulinella chromatophore N-terminome