PXD066779

PXD066779 is an original dataset announced via ProteomeXchange.

Title	Functional modes of Photosystem II under photomixotrophy in distinct variants of Synechocystis sp. PCC 6803
Description	The regulation of photosynthetic electron transport during photomixotrophic growth in cyanobacteria remains incompletely understood. In this study, we characterized four wild-type strains (WT1–WT4) of Synechocystis sp. PCC 6803 and observed distinct strain-specific differences in Photosystem II (PSII) function under photomixotrophic conditions. Specifically, WT1 and WT2 exhibited near-complete inhibition of electron transfer from QA⁻ to QB following approximately three days of glucose supplementation, resulting in a metabolic shift toward photoheterotrophy. Despite this inhibition, both strains showed improved growth compared to photoautotrophic conditions. Observed electron transport blockade correlated with increased accumulation of the PSII-associated protein Psb28-2, and an elevated PSII dimer-to-monomer ratio in WT1 and WT2. Computational modeling supports a role for Psb28-2 in limiting forward electron flow and stabilizing PSII dimers, potentially enhancing structural integrity and facilitating maintenance of the photosynthetic apparatus. This stabilization may be driven by a transient downregulation of linear electron transport to prevent over-reduction of the electron transport chain. In contrast, WT3 and WT4 maintained photomixotrophic growth throughout the experiment but exhibited slower growth rates than WT1 and WT2. Although glucose uptake was reduced in WT1 and WT2, both strains accumulated more glycogen than WT3 and WT4, suggesting divergent regulation of carbon allocation and storage metabolism. These findings highlight the capacity of cyanobacterial strains to deploy distinct metabolic strategies to optimize photosynthetic function, carbon assimilation, and energy storage under photomixotrophic conditions.
HostingRepository	PRIDE
AnnounceDate	2026-01-02
AnnouncementXML	Submission_2026-01-02_15:59:02.945.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Emil Sporre
SpeciesList	scientific name: Bacteria; NCBI TaxID: NCBITaxon:2; scientific name: Synechocystis sp. (strain PCC 6803 / Kazusa); NCBI TaxID: NEWT:1111708;
ModificationList	acetylated residue; iodoacetamide derivatized residue
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2025-07-30 12:00:44	ID requested
⏵ 1	2026-01-02 15:59:03	announced

Dataset with its publication pending

submitter keyword: cyanobacteria, DIA,Synechocystis PCC6803, orbitrap, photosystem, glucose

Yagut Allahverdiyeva-Rinne
contact affiliation	Molecular Plant Biology, Department of Life Technologies, University of Turku, Finland
contact email	allahve@utu.fi
lab head
Emil Sporre
contact affiliation	Royal Institute of Technology (KTH)
contact email	emil.sporre@scilifelab.se
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD066779
     1. Label: PRIDE project
     2. Name: Functional modes of Photosystem II under photomixotrophy in distinct variants of Synechocystis sp. PCC 6803