Gutierrez M, Huber SC, Ku SB, Kanai R, Edwards GE (1974) Intracellular location of carbon metabolism in mesophyll cells of C 4 plants. Plant Physiol 63: 821–827įurbank RT, Agostino A, Hatch MD (1990) C 4 acid decarboxylation and photosynthesis in the bundle sheath cells of NAD-malic enzyme-type C 4 plants. Plant J 6: 949–956Įdwards GE, Lilley RM, Craig S, Hatch MD (1979) Isolation of intact and functional chloroplasts from mesophyll and bundle sheath protoplasts of the C 4 plant Panicum miliaceum. Arch Biochem Biophys 202: 330–341Ĭhitty JA, Furbank RT, Marshall JS, Chen Z, Taylor WC (1994) Genetic transformation of the C 4 plant Flaveria bidentis. Biochem Biophys Res Commun 86: 1274–1280Ĭhapman KSR, Berry JA, Hatch MD (1980) Photosynthetic metabolism in the bundle sheath cells of the C 4 species Zea mays: sources of ATP and NADPH and the contribution of photosystem II. Academic Press, London, pp 39–72Ĭhapman KSR, Hatch MD (1981) Aspartate stimulation of malate decarboxylation in Zea mays bundle sheath cells: possible role in the regulation of C 4 photosynthesis. In: Lea PJ (ed) Methods in plant biochemistry, vol. Plant Physiol 24: 1–15Īshton AR, Burnell JN, Furbank RT, Jenkins CLD, Hatch MD (1990) Enzymes of C 4 photosynthesis. Annu Rev Plant Physiol 37: 93–136Īrnon DA (1949) Copper enzymes in chloroplasts. Aust J Plant Physiol 16: 279–290Īnderson JM (1986) Photoregulation of the composition, function and structure of thylakoid membranes. Possible routes of aspartate metabolism and the relationship between this metabolism and PSII activity in bundle sheath cells are considered.Īgostino A, Furbank RT, Hatch MD (1989) Maximizing photosynthetic activity and cell integrity in isolated bundle sheath cells from C 4 species. However, there was strong evidence for a rapid flux of carbon through both these pools. Time-course and pulse-chase studies following the kinetics of radiolabelling of the C-4 carboxyl of C 4 acids from 14CO 2 indicated that the photosynthetically active pool of malate was about twice the size of the aspartate pool. bidentis bundle sheath cells contained much higher activities of NADP-malate dehydrogenase and of aspartate and alanine aminotransferases. Compared with NADP-malic enzyme-type grass species, F. With bundle sheath cell preparations the maximum rates of light-dependent CO 2 fixation and malate decarboxylation to pyruvate recorded were about 1.7 μmol mg −1 Chl were recorded for cells provided with both sets of these substrates.mg −1 chlorophyll (Chl) in the light in response to adding either 3-phosphoglycerate plus HCO − 3or aspartate plus 2-oxoglutarate.Preparations of bundle sheath cells and chloroplasts isolated from these cells evolved O 2 at rates between 1.5 and 2 μmol The present studies showed that Flaveria bidentis (L.), an NADP-malic enzyme-type C 4 dicotyledon, had substantial PSII activity in bundle sheath cells and that malate and aspartate apparently contributed about equally to the transfer of CO 2 to bundle sheath cells. Massachusetts Institute of Technology.In C 4 grasses belonging to the NADP-malic enzyme-type subgroup, malate is considered to be the predominant C 4 acid metabolized during C 4 photosynthesis, and the bundle sheath cell chloroplasts contain very little photosystem-II (PSII) activity. Koch Institute for Integrative Cancer Research at MIT In addition, it also argues that commonly known metastasis indicators, including EMT genes, cell migration, or colony formation, do not always reflect metastatic capacity in vivo.ĭeficiency of malate-aspartate shuttle component SLC25A12 induces pulmonary metastasis This study highlights that certain branches of metabolism impact tumor growth and tumor metastasis differently. On the other hand, conventional in vitro metastasis assays show no indication of increased metastasis capacity of AGC1-knockdown cells. AGC1-knockdown in mouse lung carcinoma and melanoma cell lines leads to increased pulmonary metastasis following subcutaneous or intravenous injections, respectively. Low AGC1 expression correlates with worse patient prognosis in many cancers. Here, we report the impact of AGC1-knockdown on metastasis. We previously described that loss-of-aspartate glutamate carrier 1 (SLC25A12 or AGC1), an important component of the malate-aspartate shuttle, impairs cytosolic aspartate levels, NAD+/NADH ratio, mitochondrial respiration, and tumor growth. However, the impact of intracellular aspartate levels on metastasis has not been studied. Aspartate biosynthesis and its delivery to the cytosol can be crucial for tumor growth in vivo.
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