Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Lipid Metabolism and Contact Site Homologs Are Enriched at the Chloroplast Envelope-Thylakoid Interface

ABSTRACT: Biogenesis and maintenance of the photosynthetic thylakoid membrane requires transport of lipids from their site of synthesis in the chloroplast envelopes to their destination in the thylakoid. While vesicle trafficking is likely involved, we hypothesized a complementary mechanism involving direct membrane interactions. Using domain homology and proteomic profiling of chloroplast membrane fractions, we identified candidate lipid transport proteins enriched in a distinct, intermediate-density membrane population. This fraction was enriched in lipid metabolic enzymes and proteins homologous to known membrane organization factors. Several candidates, including TVP38 FAMILY PROTEIN (TVPFP), PLASMA MEMBRANE FUSION PROTEIN (PMFP), and LETM1-LIKE, localized to discrete subdomains within chloroplasts. Loss-of-function tvpfp or pmfp mutants exhibited altered chloroplast ultrastructure, including changes in thylakoid-envelope proximity, supporting their roles in maintaining membrane architecture. These findings identify a specialized chloroplast membrane region enriched in lipid-related functions and offer a foundation for elucidating the molecular architecture of these regions.

INSTRUMENT(S):

ORGANISM(S): Pisum Sativum (garden Pea)

TISSUE(S): Plant Cell, Shoot

DISEASE(S): Disease Free

SUBMITTER: Rebecca Roston

LAB HEAD: Rebecca L Roston

PROVIDER: PXD065686 | Pride | 2026-04-29

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
	20241104_RR_07_F023918.raw	Raw
	20241104_RR_07__F023918_.mzid	Mzid
	20241104_RR_07__F023918_.mzid_20241104_RR_07__F023918_.MGF	Mzid
	20241104_RR_08_F023920.raw	Raw
	20241104_RR_08__F023920_.mzid	Mzid

Items per page:

1 - 5 of 76

Similar Datasets

Lysine acetylation of chloroplast proteins 2

Project description:In photosynthesis, light is absorbed by the thylakoid embedded light harvesting pigment protein complexes (LHCs) that surround the photosynthetic reaction centers, photosystem II (PSII) and photosystem I (PSI). The distribution of light energy between the photosystems is balanced through state transitions1,2, which refer to the phosphorylation-dependent association of the loosely bound (L) LHCII antenna trimer either to PSII or PSI 3,4. Apart from phosphorylation, other mechanisms regulating state transitions have not been reported this far. In this study we demonstrate that lysine (Lys) acetylation of chloroplast proteins is a prerequisite for state transitions in Arabidopsis thaliana. Knock-out mutants lacking a chloroplast acetyltransferase NSI (At1g32070; AtNSI, SNAT) show selective decreases in the Lys acetylation status of several photosynthetic proteins including PSI, PSII and LHCII subunits. Fluorescence measurements revealed that changes in the wavelength of illumination do not cause state transitions in the nsi mutants even though their LHCII phosphorylation status is not defected. Furthermore, biochemical analyses of thylakoid proteins and protein complexes showed that nsi plants are not able to accumulate the phosphorylation dependent PSI-LHCII megacomplex. Our results manifest that Lys acetylation by NSI has an integral role in the regulation of state transitions in Arabidopsis.

2018-07-03 | PXD007630 | Pride

Conserved function of UPF0016 manganese transporter across human, plant and bacteria

Project description:The Uncharacterized Protein Family 0016 (UPF0016) is conserved throughout evolution. In humans, the member TMEM165 is a putative Golgi localized Ca2+ and/or Mn2+ transporter. Genes encoding UPF0016 proteins are also present in many bacteria, including the cyanobacteria Synechocystis (MNX/SynPAM71), where it has been described as Mn2+ exporter. In Arabidopsis, two members of this family are embedded in the chloroplast membranes; the CMT1 protein is localized in the inner envelope membrane and the PAM71 protein is localized in the thylakoid membrane, and both cooperate to transport Mn2+ to the oxygen evolving complex of photosystem II. We used the pam71 mutant of Arabidopsis as a platform to perform intra- and inter-species complementation assays. The N-terminus of PAM71 was fused in front of TMEM165, CMT1 and MNX to direct them into chloroplast membranes. We performed LC-MS/MS experiments to assess their sub-plastidial localization.

2021-04-20 | PXD022763 | Pride

Proteomic analysis of different pgr5 mutants and pgrl1ab in Arabidopsis thaliana

Project description:PGR5 is a small chloroplast protein that performs cyclic electron flow (CEF) around photosystem I and it is required for the proton gradient generation across the thylakoid membrane. The level of this protein is closely regulated by PGRL1. However, the molecular mechanism of PGR5 is still elusive. In this work, we have generated a new pgr5 mutant in Arabidopsis using CRISPR-Cas9 technology, pgr5-Cas, completely devoid of PGR5. We performed comparative proteomic analysis on pgr5-1 and pgr5-Cas lines (#1 and #2), as well as on pgrl1ab mutant.

2022-08-12 | PXD028563 | Pride

Analysis of thylakoid membrane proteome in Arabidopsis thaliana

Project description:To explore the role and target of chloroplast proteases under heat stress, thylakoid membranes were isolated from wild-type and mutant chloroplast thylakoid membrane-localized proteases after heat stress and subjected to comparative quantification by LC-MS/MS analysis using the spectral counting method.

2020-12-06 | PXD022899 | JPOST Repository

STIC2 selectively binds ribosome-nascent chain complexes in the cotranslational sorting of Arabidopsis thylakoid proteins

Project description:Chloroplast-encoded multi-span thylakoid membrane proteins are crucial for photosynthetic complexes, yet the coordination of their biogenesis remains poorly understood. To identify factors that specifically support the cotranslational biogenesis of the reaction center protein D1 of photosystem (PS) II, we generated and affinity-purified stalled ribosome-nascent chain complexes (RNCs) bearing D1 nascent chains. Stalled RNCs translating the soluble ribosomal subunit uS2c were used for comparison. Quantitative tandem-mass spectrometry of the purified RNCs identified around 140 proteins specifically associated with D1 RNCs, mainly involved in protein and cofactor biogenesis, including chlorophyll biosynthesis, and other metabolic pathways. Functional analysis of STIC2, a newly identified D1 RNC interactor, revealed its cooperation with chloroplast protein SRP54 in the de novo biogenesis and repair of D1, and potentially other cotranslationally-targeted reaction center subunits of PSII and PSI. The primary binding interface between STIC2 and the thylakoid insertase Alb3 and its homolog Alb4 was mapped to STIC2’s β-sheet region, and the conserved Motif III in the C-terminal regions of Alb3/4.

2024-08-28 | PXD042896 | Pride

LC-MS/MS of chloroplasts from WT plants and fractionated the proteins into the membrane and stroma fractions

Project description:To confirm the localization of GCSC1 to chloroplast vesicle rather than in the stroma, we purified chloroplasts from WT plants and fractionated the proteins into the membrane and stroma fractions. Quantification of proteins by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that GCSC1 was present only in the membrane fractions, co-existing with several chloroplast membrane proteins.

2024-09-26 | PXD056230 | Pride

Chloroplast nucleoid is organized by membrane association of transcribed genes [ChIP]

Project description:Chloroplasts are organelles responsible for photosynthesis. They originated form a procaryotic ancestor in the process of endosymbiosis and contain their own genomes. The chloroplast genome is packaged into a chromatin-like structure known as the nucleoid. The internal arrangement of the nucleoid, molecular mechanisms of DNA packaging and connection of the nucleoid structure to gene expression remain poorly understood. We show that Arabidopsis thaliana chloroplast nucleoids have a unique organization driven by DNA binding to the thylakoid membranes. Membrane association of specific DNA regions is correlated with high levels of transcription, high protein occupancy and reduced DNA accessibility. Genes with low levels of transcription are further away from the membranes, have lower protein occupancy and higher DNA accessibility. Gene-specific disruption of transcription in sigma factor mutants causes a corresponding reduction in membrane association, indicating that RNA polymerase activity causes DNA tethering to the membranes. We propose that transcription organizes the chloroplast nucleoid into a transcriptionally active membrane-associated core and a less active Periphery.

2023-05-10 | GSE228226 | GEO

Chloroplast nucleoid is organized by membrane association of transcribed genes [ATAC]

2023-05-10 | GSE228224 | GEO

Chloroplast nucleoid is organized by membrane association of transcribed genes [SOLINA]

2023-05-10 | GSE228229 | GEO

Chloroplast nucleoid is organized by membrane association of transcribed genes [IPOD]

2023-05-10 | GSE228228 | GEO