PXD073316

PXD073316 is an original dataset announced via ProteomeXchange.

Title	GUN5 confers cold stress tolerance by coordinating the assembly of the GluTR complex to sustain tetrapyrrole biosynthesis
Description	Chloroplast biogenesis during cold acclimation requires the precise coordination of tetrapyrrole biosynthesis (TPB) to prevent photo-oxidative damage while maintaining photosynthetic capacity. Here, we report that the H-subunit (CHLH, also named GENOMES UNCOUPLED5, GUN5) of Mg-chelatase is essential for the cold adaptation. We identified the gun5-1 mutant, (an allele from the previous gun5 mutant) which exhibits a severe chlorotic phenotype with a metabolic hindrance in chloroplasts under cold stress. We demonstrate that cold stress-incubated wild-type seedlings post-translationally stabilize CHLH/GUN5 in an assembled high-molecular-weight complex with GUN4, NADPH:protochlorophyllide oxidoreductase (POR), and glutamyl-tRNA reductase (GluTR), the rate-limiting enzyme of TPB pathway. In gun5-1, the disruption of this multienzymatic complex leads to the sequestration of the mutant GUN5 protein in the stroma and the accumulation of GluTR in inactive aggregates, resulting in a cessation of the TPB metabolic pathway. Our findings reveal a regulatory mechanism in which GUN5 goes beyond its catalytic role as a structural component and physically couples upstream and downstream enzymatic steps to optimize chlorophyll biosynthesis under cold stress.
HostingRepository	iProX
AnnounceDate	2026-01-20
AnnouncementXML	Submission_2026-01-20_23:42:10.765.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Liping Feng
SpeciesList	scientific name: Arabidopsis thaliana; NCBI TaxID: 3702;
ModificationList	No PTMs are included in the dataset
Instrument	LTQ

Revision	Datetime	Status	ChangeLog Entry
0	2026-01-20 23:35:38	ID requested
⏵ 1	2026-01-20 23:42:11	announced

Dataset with its publication pending

submitter keyword: chlorophyll biosynthesis, GUN5, GluTR, cold

Guozhang Wu
contact affiliation	Shanghai Jiaotong University
contact email	gzwu@sjtu.edu.cn
lab head
Liping Feng
contact affiliation	Shanghai Jiao Tong University
contact email	lipingfeng@sjtu.edu.cn
dataset submitter

iProX dataset URI