Redox-shuttling between chloroplast and cytosol: integration of intra-chloroplast and extra-chloroplast metabolism

• Published in: Current opinion in plant biology Vol. 15; no. 3; pp. 252 - 260
• Main Authors: Taniguchi, Mitsutaka, Miyake, Hiroshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.06.2012; Elsevier
• Subjects: biochemical pathways; Biological and medical sciences; C4 plants; carbon; Carbon - metabolism; chloroplasts; Chloroplasts - metabolism; Citric Acid Cycle - physiology; cytosol; Cytosol - metabolism; enzymatic reactions; enzymes; Fundamental and applied biological sciences. Psychology; isozymes; leaves; Mitochondria - metabolism; Models, Biological; nitrogen; Nitrogen - metabolism; Oxidation-Reduction; Photosynthesis - physiology; Plant Leaves - cytology; Plant Leaves - metabolism; Plant Leaves - physiology; transporters; Plant biology; Oxidation reduction; Review; Metabolism; Cytosol; Chloroplast
• ISSN: 1369-5266; 1879-0356
• DOI: 10.1016/j.pbi.2012.01.014

► Two redox shuttle systems across chloroplast envelope maintain metabolic balance. ► The chloroplastic 2-oxoglutarate/malate transporter has multiple roles as malate valve and in carbon/nitrogen metabolism. ► The shuttle systems are finely controlled in response to the stromal redox state. ► In the leaves of C4 plants, the redox shuttle systems are localized cell-specifically and link to cellular metabolic pathways. Reducing equivalents produced in the chloroplast are essential for many key cellular metabolic enzyme reactions. Two redox shuttle systems transfer reductant out of the chloroplast; these systems consist of metabolite transporters, coupled with stromal and cytosolic dehydrogenase isozymes. The transporters function in the redox shuttle and also operate as key enzymes in carbon/nitrogen metabolism. To maintain adequate levels of reductant and proper metabolic balance, the shuttle systems are finely controlled. Also, in the leaves of C4 plants, cell-specific division of carbon and nitrogen assimilation includes cell-specific localization of the redox shuttle systems. The redox shuttle systems are tightly linked to cellular metabolic pathways and are essential for maintaining metabolic balance between energy and reducing equivalents.