首页|Activation of stress-response genes by retrograde signaling-mediated destabilization of nuclear importin IMPα-9 and its interactor TPR2
Activation of stress-response genes by retrograde signaling-mediated destabilization of nuclear importin IMPα-9 and its interactor TPR2
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
万方数据
维普
Stress-induced retrograde signal transmission from the plastids to the nucleus has long puzzled plant bi-ologists.To address this,we performed a suppressor screen of the ceh1 mutant,which contains elevated 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate(MEcPP)levels,and identified the gain-of-function mutant impα-9,which shows reversed dwarfism and suppressed expression of stress-response genes in the ceh1 background despite heightened MEcPP.Subsequent genetic and biochemical analyses estab-lished that the accumulation of MEcPP initiates an upsurge in Arabidopsis SKP1-like 1(ASK1)abundance,a pivotal component in the proteasome degradation pathway.This increase in ASK1 prompts the degrada-tion of IMPα-9.Moreover,we uncovered a protein-protein interaction between IMPα-9 and TPR2,a tran-scriptional co-suppressor and found that a reduction in IMPα-9 levels coincides with a decrease in TPR2 abundance.Significantly,the interaction between IMPα-9 and TPR2 was disrupted in impα-9mutants,high-lighting the critical role of a single amino acid alteration in maintaining their association.Disruption of their interaction results in the reversal of MEcPP-associated phenotypes.Chromatin immunoprecipitation coupled with sequencing analyses revealed that TPR2 binds globally to stress-response genes and sug-gested that IMPα-9 associates with the chromatin.They function together to suppress the expression of stress-response genes under normal conditions,but this suppression is alleviated in response to stress through the degradation of the suppressing machinery.The biological relevance of our discoveries was validated under high light stress,marked by MEcPP accumulation,elevated ASK1 levels,IMPα-9 degreda-tion,reduced TPR2 abundance,and subsequent activation of a network of stress-response genes.In summary,our study collectively unveils fresh insights into plant adaptive mechanisms,highlighting intri-cate interactions among retrograde signaling,the proteasome,and nuclear transport machinery.
Department of Botany and Plant Sciences,Institute of Integrative Genome Biology,University of California,Riverside,Riverside,CA 92521,USA
School of Medicine,University of California,Riverside,Riverside,CA 92521,USA
National Institutes of HealthNational Institutes of Health(NIH)National Science FoundationNational science Foundation(NSF)Dr.John W.Leibacher and Mrs.Kathy Cookson endowed chair funds
万方数据
维普
