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          Institute: MPI für molekulare Pflanzenphysiologie     Collection: Publikationen Pflanzenphysiologie     Display Documents



ID: 127404.0, MPI für molekulare Pflanzenphysiologie / Publikationen Pflanzenphysiologie
Enzymes of glycolysis are functionally associated with the mitochondrion in Arabidopsis cells
Authors:Giege, P.; Heazlewood, J. L.; Roessner-Tunali, U.; Millar, A. H.; Fernie, A. R.; Leaver, C. J.; Sweetlove, L. J.
Date of Publication (YYYY-MM-DD):2003
Title of Journal:Plant Cell
Volume:15
Issue / Number:9
Start Page:2140
End Page:2151
Review Status:not specified
Audience:Not Specified
Abstract / Description:Mitochondria fulfill a wide range of metabolic functions in addition to the synthesis of ATP and contain a diverse array of proteins to perform these functions. Here, we present the unexpected discovery of the presence of the enzymes of glycolysis in a mitochondrial fraction of Arabidopsis cells. Proteomic analyses of this mitochondrial fraction revealed the presence of 7 of the 10 enzymes that constitute the glycolytic pathway. Four of these enzymes (glyceraldehyde-3-P dehydrogenase, aldolase, phosphoglycerate mutase, and enolase) were also identified in an intermembrane space/outer mitochondrial membrane fraction. Enzyme activity assays confirmed that the entire glycolytic pathway was present in preparations of isolated Arabidopsis mitochondria, and the sensitivity of these activities to protease treatments indicated that the glycolytic enzymes are present on the outside of the mitochondrion. The association of glycolytic enzymes with mitochondria was confirmed in vivo by the expression of enolase- and aldolase-yellow fluorescent protein fusions in Arabidopsis protoplasts. The yellow fluorescent protein fluorescence signal showed that these two fusion proteins are present throughout the cytosol but are also concentrated in punctate regions that colocalized with the mitochondrion-specific probe Mitotracker Red. Furthermore, when supplied with appropriate cofactors, isolated, intact mitochondria were capable of the metabolism of C-13-glucose to C-13-labeled intermediates of the trichloroacetic acid cycle, suggesting that the complete glycolytic sequence is present and active in this subcellular fraction. On the basis of these data, we propose that the entire glycolytic pathway is associated with plant mitochondria by attachment to the cytosolic face of the outer mitochondrial membrane and that this microcompartmentation of glycolysis allows pyruvate to be provided directly to the mitochondrion, where it is used as a respiratory substrate. [References: 67] 67
Free Keywords:Higher-plant mitochondria. Protein identification technology.
; Castor-oil seeds. Alternative oxidase. Suspension-cultures. Cytosolic
; aldolase. Electron-transport. Mass-spectrometry. Oxidative stress.
; Draft sequence.
; Plant Sciences in Current Contents(R)/Agricultural, Biology &
; Environmental Sciences
; Animal & Plant Sciences in Current Contents(R)/Life Sciences.
; 2003 week 41
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für molekulare Pflanzenphysiologie/Molekulare Physiologie/AG Willmitzer/Fernie
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