PXD050257-1

PXD050257 is an original dataset announced via ProteomeXchange.

Title	Absence of Flv3 results in metabolic and bioenergetic rearrangements towards mixotrophy in engineered sucrose-excreting Synechocystis sp. PCC6803
Description	In the cyanobacterium Synechocystis sp. PCC 6803, the flavodiiron protein Flv3 functions as an alternative electron acceptor from PSI and represents an interesting engineering target for reorganizing the electron and carbon fluxes in the cell. We have shown that the inactivation of Flv3 in engineered sucrose-excreting Synechocystis (S02:Δflv3) triggers sucrose reuptake from the growth medium, and leads to a transition from photoautotrophy to mixotrophy. Such an acclimation maintains optimal growth of the S02:Δflv3 strain through enhanced respiratory metabolism evidenced by extensive but gradual proteomic and metabolomic changes over the course of the nine-day experiment. In the absence of Flv3, a downregulation of photosynthetic light reactions and CO2 assimilation with concurrent upregulation of glycolytic pathways occurred before any differences in sucrose production between S02 and S02:Δflv3 strains were observed. Subsequently, the components of the respiratory pathways showed distinct upregulation in S02:Δflv3, including the plastoquinone reductase complexes NDH-11 and NDH-2, which function at the interphase between glycolytic metabolism and the electron transport pathways, and the terminal respiratory oxidases Cyd and Cox, which direct electrons to O2. Increased oxygen consumption together with lower rates of photosynthetic light reactions generating oxygen led to activation fermentative pathways in S02:Δflv3 as an alternative source of energy for the cells. Our results show that although Synechocystis cannot directly compensate for the lack of Flv3 by other alternative electron acceptors under continuous high light, high CO2 and high osmotic pressure, the cells respond to the increased electron pressure by extensive reorganization of the electron transfer pathways. While glycolytic metabolism is significantly up-regulated to provide energy for the cell, the accumulation of storage compounds and increased respiration serve as indirect electron sinks for photosynthetic electrons that would normally be consumed by the Flv1/Flv3 heterodimer.
HostingRepository	PanoramaPublic
AnnounceDate	2025-10-31
AnnouncementXML	Submission_2025-10-31_15:00:11.693.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Dorota Muth-Pawlak
SpeciesList	scientific name: Synechocystis sp. PCC 6803; NCBI TaxID: 1148;
ModificationList	Acetyl; Carbamidomethyl; Oxidation
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2024-02-29 22:49:23	ID requested
⏵ 1	2025-10-31 15:00:12	announced

Muth-Pawlak D, Kakko L, Kallio P, Aro EM, Interplay between photosynthetic electron flux and organic carbon sinks in sucrose-excreting Synechocystis sp. PCC 6803 revealed by omics approaches. Microb Cell Fact, 23(1):188(2024) [pubmed]

submitter keyword: Synechocystis, photosynthesis, respiration, sucrose production, trophic growth

Dorota Muth-Pawlak
contact affiliation	University of Turku
contact email	dorota.muth@utu.fi
lab head
Dorota Muth-Pawlak
contact affiliation	University of Turku
contact email	dorota.muth@utu.fi
dataset submitter

Panorama Public dataset URI