PMID:19293385

Citation	Lee, JR, Lee, SS, Jang, HH, Lee, YM, Park, JH, Park, SC, Moon, JC, Park, SK, Kim, SY, Lee, SY, Chae, HB, Jung, YJ, Kim, WY, Shin, MR, Cheong, GW, Kim, MG, Kang, KR, Lee, KO, Yun, DJ and Lee, SY (2009) Heat-shock dependent oligomeric status alters the function of a plant-specific thioredoxin-like protein, AtTDX. Proc. Natl. Acad. Sci. U.S.A. 106:5978-83
Abstract	We found that Arabidopsis AtTDX, a heat-stable and plant-specific thioredoxin (Trx)-like protein, exhibits multiple functions, acting as a disulfide reductase, foldase chaperone, and holdase chaperone. The activity of AtTDX, which contains 3 tetratricopeptide repeat (TPR) domains and a Trx motif, depends on its oligomeric status. The disulfide reductase and foldase chaperone functions predominate when AtTDX occurs in the low molecular weight (LMW) form, whereas the holdase chaperone function predominates in the high molecular weight (HMW) complexes. Because deletion of the TPR domains results in a significant enhancement of AtTDX disulfide reductase activity and complete loss of the holdase chaperone function, our data suggest that the TPR domains of AtTDX block the active site of Trx and play a critical role in promoting the holdase chaperone function. The oligomerization status of AtTDX is reversibly regulated by heat shock, which causes a transition from LMW to HMW complexes with concomitant functional switching from a disulfide reductase and foldase chaperone to a holdase chaperone. Overexpression of AtTDX in Arabidopsis conferred enhanced heat shock resistance to plants, primarily via its holdase chaperone activity.
Links	PubMed PMC2667072 Online version:10.1073/pnas.0811231106
Keywords	Arabidopsis Proteins/physiology; Dimerization; Heat-Shock Response/genetics; Molecular Chaperones; Molecular Weight; NADH, NADPH Oxidoreductases; Thioredoxins/physiology
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ARATH:TDX	involved_in	GO:0010286: heat acclimation	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
ARATH:TDX	enables	GO:0016671: oxidoreductase activity, acting on a sulfur group of donors, disulfide as acceptor	ECO:0000314: direct assay evidence used in manual assertion		F		Seeded From UniProt	complete
ARATH:TDX	involved_in	GO:0006457: protein folding	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete
ARATH:TDX	involved_in	GO:0051259: protein complex oligomerization	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete
ARATH:TDX	enables	GO:0042802: identical protein binding	ECO:0000353: physical interaction evidence used in manual assertion	UniProtKB:Q8VWG7	F		Seeded From UniProt	complete

References

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