VTC1与CSN5B的互作影响拟南芥VC含量及氧化胁迫反应
|
摘要
维生素C(VC)是普遍存在于植物和真核藻类体内的高丰度水溶性小分子抗氧化物质,在植物的生长发育、非生物胁迫和生物胁迫应答中具有重要的生物学功能。已有证据表明植物体内存在多条VC合成途径,包括L-半乳糖途径、古洛糖途径、糖醛酸途径和肌醇途径。其中L-半乳糖途径把VC的生物合成融入碳水化合物的主要代谢过程并与多糖合成及蛋白质糖基化联系起来,已被公认为植物中VC合成的最主要途径。研究表明,拟南芥GDP-甘露糖焦磷酸化酶(GMPase)是此途径中的一个关键酶,编码该酶的基因命名为VTC1。VTC1点突变体vtc1-1并没有改变VTC1的转录表达,只是降低了35%酶活以及70%VC含量(仅为野生型VC含量的25-30%),导致对臭氧、UV-B、SO2、高光强、盐、H2O2的敏感性。
光是影响植物体内VC含量的一个重要环境因子,且VC在光保护中起重要作用。光合作用、光呼吸和其它氧化胁迫产生的活性氧(ROS)都可以通过VC清除。拟南芥L-半乳糖途径的几个重要酶均在转录水平上受到光调控,VTC1、GPP、GalLDH、VTC2在持续光照下基因表达升高,持续暗处理下基因表达降低。但是目前光调控VC合成的机制尤其是在蛋白水平上还不是很清楚。
以AtVTC1为诱饵通过酵母双杂技术筛选拟南芥三天黄化苗的cDNA文库,得到三个与其互作的蛋白质因子。其中一个即为CSN5B,CSN5B是与“组成型光形态建成”密切相关的COP9信号复合体(COP9 signalosome,CSN)的一个亚基,CSN由8个亚基组成,依次为CSN1—8,此复合物可以通过泛素降解途径调节植物对光信号的应答,从而使植物体完成从光形态建成到暗生长的转换。CSN是通过对SCF型E3-泛素连接酶的去NEDD化来调控泛素降解系统的,CSN5对于整个复合体而言具有相对独立性,CSN5的单个亚基突变就能引起CSN突变体所有表型的出现,CSN5对植物的生长发育具有重要的调控作用。
通过酵母双杂交、BiFC、pull-down和CoIP等实验验证了AtVTC1与AtCSN5B确实存在相互作用。为了进一步探讨CSN5B对VTC1的调控作用,我们从植物体VC含量和对氧化胁迫耐受性方面考察了它们之间的相互作用。CSN5B缺失突变体csn5b的生长发育与野生型并无明显差异,但检测到其VC含量比野生型要高20%左右,而过表达CSN5B后VC含量比野生型低;同时过表达CSN5B后其活性氧含量比野生型有所增加。从蛋白水平上看,拟南芥VTC1过表达植株与CSN5B过表达植株杂交后VTC1的蛋白含量比杂交前明显降低。
以上结果表明,拟南芥中CSN5B通过调控VTC1的降解而影响植物体内的VC含量,并进而引起植物对氧化胁迫耐受性的变化。
Vitamin C (VC), the most abundant water-soluble small molecular antioxidant in plants and eukaryotic algae, plays roles in plant development and response to abiotic and biotic stresses. It has been verified that there are several pathways of VC biosynthesis in plants, including L-galactose pathway, Gulose pathway, Uronic acid pathway, and myo-inositol pathway. The L-galactose pathway integrates VC biosynthesis to carbohydrate metabolism, amylase synthesis and protein glycosylation, which makes it to be the major route of VC synthesis in plants. VTC1 encodes one key enzyme GDP-D-Mannose pyrophosphorylase (GMPase). VC-reduced Arabidopsis thaliana mutant vtc1-1 habors a mis-sense mutation, resulting in the enzyme activity reduction by 35% compared with that of wild type without any changes of VTC1 transcripts. And the VC contents in the mutant decrease to 25-30% of that in wild type, consequently increasing the sensitivity to ozone, UV-B, SO2, high light, salt stress and H2O2.
Light intensity is the major environmental factor affecting leaf VC contents, meanwhile VC plays a role in preventing plants from light-induced damage. The reactive oxygen species (ROS) produced in photosynthesis, photorespiration and oxidative stresses could be scavenged through VC transformation from reduced to oxidized status. The key enzymes of L-galactose pathway in A. thaliana are light-regulated in transcript level, and expression of VTC1、GPP、GalLDH、VTC2 increase in constant light-acclimated leaves and decrease under constant darkness. However, the mechanism that how light regulates VC synthesis, especially in post-translation level, is still not clear.
In this work, we used the yeast two-hybrid system to isolate proteins able to interact with AtVTC1. By the system, we have isolated 3 putative proteins that might interact with AtVTC1, screened from a 3 day-old etiolated Arabidopsis seedling cDNA library. One of the proteins is CSN5B known as a subunit of COP9 signalosome (CSN), which is consist of 8 subunits named CSN1-8. The CSN complex plays a part in promoting an alternative developmental program (skotomorphogenesis to photomorphogenesis) through ubiquitin degradation pathway in response to a changing light environment. By monitoring the derubylation status of SCF E3 ubiquitin ligases, CSN participates in ubiquitin degradation system, CSN5 is relatively independent to the whole complex, the single mutated CSN5 would results in the phenotypes of all CSN mutants, and CSN5 has a crucial modulation in plant development.
After identification of the interaction between AtVTC1 and AtCSN5B by way of yeast two hybrid, BiFC, pull-down and CoIP, we then detected plants VC content and tolerance to oxidative stress. The VC content in csn5b mutant, complete lack of the CSN5B transcripts, was 20% more than that in wild type, although seedlings did not show obvious different phenotypes between wild type and csn5b. The transgenic lines overexpressing CSN5B decreased VC content, compared to that of wild type, which resulted in the ROS in OECSN5B increased. And AtVTC1 protein quantities in OEVTC1/OECSN5B were apparently less than that in OEVTC1.
The results above indicate that CSN5B plays an important role in modulation of plant VC synthesis and in influence of plant response to oxidative stress in A. thaliana, as a result of the degradation of VTC1 protein by CSN5B.
光是影响植物体内VC含量的一个重要环境因子,且VC在光保护中起重要作用。光合作用、光呼吸和其它氧化胁迫产生的活性氧(ROS)都可以通过VC清除。拟南芥L-半乳糖途径的几个重要酶均在转录水平上受到光调控,VTC1、GPP、GalLDH、VTC2在持续光照下基因表达升高,持续暗处理下基因表达降低。但是目前光调控VC合成的机制尤其是在蛋白水平上还不是很清楚。
以AtVTC1为诱饵通过酵母双杂技术筛选拟南芥三天黄化苗的cDNA文库,得到三个与其互作的蛋白质因子。其中一个即为CSN5B,CSN5B是与“组成型光形态建成”密切相关的COP9信号复合体(COP9 signalosome,CSN)的一个亚基,CSN由8个亚基组成,依次为CSN1—8,此复合物可以通过泛素降解途径调节植物对光信号的应答,从而使植物体完成从光形态建成到暗生长的转换。CSN是通过对SCF型E3-泛素连接酶的去NEDD化来调控泛素降解系统的,CSN5对于整个复合体而言具有相对独立性,CSN5的单个亚基突变就能引起CSN突变体所有表型的出现,CSN5对植物的生长发育具有重要的调控作用。
通过酵母双杂交、BiFC、pull-down和CoIP等实验验证了AtVTC1与AtCSN5B确实存在相互作用。为了进一步探讨CSN5B对VTC1的调控作用,我们从植物体VC含量和对氧化胁迫耐受性方面考察了它们之间的相互作用。CSN5B缺失突变体csn5b的生长发育与野生型并无明显差异,但检测到其VC含量比野生型要高20%左右,而过表达CSN5B后VC含量比野生型低;同时过表达CSN5B后其活性氧含量比野生型有所增加。从蛋白水平上看,拟南芥VTC1过表达植株与CSN5B过表达植株杂交后VTC1的蛋白含量比杂交前明显降低。
以上结果表明,拟南芥中CSN5B通过调控VTC1的降解而影响植物体内的VC含量,并进而引起植物对氧化胁迫耐受性的变化。
Vitamin C (VC), the most abundant water-soluble small molecular antioxidant in plants and eukaryotic algae, plays roles in plant development and response to abiotic and biotic stresses. It has been verified that there are several pathways of VC biosynthesis in plants, including L-galactose pathway, Gulose pathway, Uronic acid pathway, and myo-inositol pathway. The L-galactose pathway integrates VC biosynthesis to carbohydrate metabolism, amylase synthesis and protein glycosylation, which makes it to be the major route of VC synthesis in plants. VTC1 encodes one key enzyme GDP-D-Mannose pyrophosphorylase (GMPase). VC-reduced Arabidopsis thaliana mutant vtc1-1 habors a mis-sense mutation, resulting in the enzyme activity reduction by 35% compared with that of wild type without any changes of VTC1 transcripts. And the VC contents in the mutant decrease to 25-30% of that in wild type, consequently increasing the sensitivity to ozone, UV-B, SO2, high light, salt stress and H2O2.
Light intensity is the major environmental factor affecting leaf VC contents, meanwhile VC plays a role in preventing plants from light-induced damage. The reactive oxygen species (ROS) produced in photosynthesis, photorespiration and oxidative stresses could be scavenged through VC transformation from reduced to oxidized status. The key enzymes of L-galactose pathway in A. thaliana are light-regulated in transcript level, and expression of VTC1、GPP、GalLDH、VTC2 increase in constant light-acclimated leaves and decrease under constant darkness. However, the mechanism that how light regulates VC synthesis, especially in post-translation level, is still not clear.
In this work, we used the yeast two-hybrid system to isolate proteins able to interact with AtVTC1. By the system, we have isolated 3 putative proteins that might interact with AtVTC1, screened from a 3 day-old etiolated Arabidopsis seedling cDNA library. One of the proteins is CSN5B known as a subunit of COP9 signalosome (CSN), which is consist of 8 subunits named CSN1-8. The CSN complex plays a part in promoting an alternative developmental program (skotomorphogenesis to photomorphogenesis) through ubiquitin degradation pathway in response to a changing light environment. By monitoring the derubylation status of SCF E3 ubiquitin ligases, CSN participates in ubiquitin degradation system, CSN5 is relatively independent to the whole complex, the single mutated CSN5 would results in the phenotypes of all CSN mutants, and CSN5 has a crucial modulation in plant development.
After identification of the interaction between AtVTC1 and AtCSN5B by way of yeast two hybrid, BiFC, pull-down and CoIP, we then detected plants VC content and tolerance to oxidative stress. The VC content in csn5b mutant, complete lack of the CSN5B transcripts, was 20% more than that in wild type, although seedlings did not show obvious different phenotypes between wild type and csn5b. The transgenic lines overexpressing CSN5B decreased VC content, compared to that of wild type, which resulted in the ROS in OECSN5B increased. And AtVTC1 protein quantities in OEVTC1/OECSN5B were apparently less than that in OEVTC1.
The results above indicate that CSN5B plays an important role in modulation of plant VC synthesis and in influence of plant response to oxidative stress in A. thaliana, as a result of the degradation of VTC1 protein by CSN5B.
引文
1. Agius F, G.-L., CaballeroJL,Munoz-Blanco J, BotellaMA,ValpuestaV. (2003). Engineeringincreased vitamin C levels in plants by overexpression of a D-galacturonic acidreductase. Nat Biotechnol 21, 177-181.
2. Arrigoni, O. (1994). Ascorbate system in plant development. J Bioenerg Biomembr 26, 407-419.
3. Barth, C., De Tullio, M., and Conklin, P.L. (2006). The role of ascorbic acid in the control of flowering time and the onset of senescence. J Exp Bot 57, 1657-1665.
4. Bartoli, C.G., Yu, J., Gomez, F., Fernandez, L., McIntosh, L., and Foyer, C.H. (2006). Inter-relationships between light and respiration in the control of ascorbic acid synthesis and accumulation in Arabidopsis thaliana leaves. J Exp Bot 57, 1621-1631.
5. Brunhuber, N.M., Mort, J.L., Christoffersen, R.E., and Reich, N.O. (2000). Steady-state kinetic mechanism of recombinant avocado ACC oxidase: initial velocity and inhibitor studies. Biochemistry 39, 10730-10738.
6. Burger-Kentischer, A., Finkelmeier, D., Thiele, M., Schmucker, J., Geiger, G., Tovar, G.E., and Bernhagen, J. (2005). Binding of JAB1/CSN5 to MIF is mediated by the MPN domain but is independent of the JAMM motif. FEBS Lett 579, 1693-1701.
7. Chamovitz, D.A., Wei, N., Osterlund, M.T., von Arnim, A.G., Staub, J.M., Matsui, M., and Deng, X.W. (1996). The COP9 complex, a novel multisubunit nuclear regulator involved in light control of a plant developmental switch. Cell 86, 115-121.
8. Chatterjee, I.B. (1973). Evolution and the biosynthesis of ascorbic acid. Science 182, 1271-1272.
9. Chen, Z., and Gallie, D.R. (2004). The ascorbic acid redox state controls guard cell signaling and stomatal movement. Plant Cell 16, 1143-1162.
10. Chen, Z., Young, T.E., Ling, J., Chang, S.C., and Gallie, D.R. (2003). Increasing vitamin C content of plants through enhanced ascorbate recycling. Proc Natl Acad Sci U S A 100, 3525-3530.
11. Conklin, P.L. (2004). Ascorbic acid, a familiar small molecule intertwined in the response of plants to ozone, pathogens, and the onset of senescence. Plant Cell and Environment 27, 959-960.
12. Conklin, P.L., Norris, S.R., Wheeler, G.L., Williams, E.H., Smirnoff, N., and Last, R.L. (1999). Genetic evidence for the role of GDP-mannose in plant ascorbic acid (vitamin C) biosynthesis. Proc Natl Acad Sci U S A 96, 4198-4203.
13. Cope, G.A., Suh, G.S., Aravind, L., Schwarz, S.E., Zipursky, S.L., Koonin, E.V., and Deshaies, R.J. (2002). Role of predicted metalloprotease motif of Jab1/Csn5 in cleavage of Nedd8 from Cul1. Science 298, 608-611.
14. Damoc, E., Fraser, C.S., Zhou, M., Videler, H., Mayeur, G.L., Hershey, J.W., Doudna, J.A., Robinson, C.V., and Leary, J.A. (2007). Structural characterization of the human eukaryotic initiation factor 3 protein complex by mass spectrometry. Mol Cell Proteomics 6, 1135-1146.
15. Daniel, A.C. (2009). Revisiting the COP9 signalosome as a transcriptional regulator. EMBO J 10,352-358.
16. DeBolt, S., Cook, D.R., and Ford, C.M. (2006). L-tartaric acid synthesis from vitamin C in higher plants. Proc Natl Acad Sci U S A 103, 5608-5613.
17. Deshaies, R.J., and Meyerowitz, E. (2000). COP1 patrols the night beat. Nat Cell Biol 2, E102-104.
18. Dohmann, E.M., Kuhnle, C., and Schwechheimer, C. (2005). Loss of the CONSTITUTIVE PHOTOMORPHOGENIC9 signalosome subunit 5 is sufficient to cause the cop/det/fus mutant phenotype in Arabidopsis. Plant Cell 17, 1967-1978.
19. Dowdle, J., Ishikawa, T., Gatzek, S., Rolinski, S., and Smirnoff, N. (2007). Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability. Plant J 52, 673-689.
20. Dutilleul, C., Garmier, M., Noctor, G., Mathieu, C., Chetrit, P., Foyer, C.H., and de Paepe, R. (2003). Leaf mitochondria modulate whole cell redox homeostasis, set antioxidant capacity, and determine stress resistance through altered signaling and diurnal regulation. Plant Cell 15, 1212-1226.
21. Fukumoto, A., Tomoda, K., Kubota, M., Kato, J.Y., and Yoneda-Kato, N. (2005). Small Jab1-containing subcomplex is regulated in an anchorage- and cell cycle-dependent manner, which is abrogated by ras transformation. FEBS Lett 579, 1047-1054.
22. Fukunaga, K., Fujikawa, Y., and Esaka, M. (2010). Light Regulation of Ascorbic Acid Biosynthesis in Rice via Light Responsive cis-Elements in Genes Encoding Ascorbic Acid Biosynthetic Enzymes. Biosci Biotechnol Biochem 74, 90929-90921-90924.
23. Gatzek, S., Wheeler, G.L., and Smirnoff, N. (2002). Antisense suppression of l-galactose dehydrogenase in Arabidopsis thaliana provides evidence for its role in ascorbate synthesis and reveals light modulated l-galactose synthesis. Plant J 30, 541-553.
24. Grace, S.C., and Logan, B.A. (1996). Acclimation of Foliar Antioxidant Systems to Growth Irradiance in Three Broad-Leaved Evergreen Species. Plant Physiol 112, 1631-1640.
25. Green, M.A., and Fry, S.C. (2005). Vitamin C degradation in plant cells via enzymatic hydrolysis of 4-O-oxalyl-L-threonate. Nature 433, 83-87.
26. Gusmaroli, G., Feng, S., and Deng, X.W. (2004). The Arabidopsis CSN5A and CSN5B subunits are present in distinct COP9 signalosome complexes, and mutations in their JAMM domains exhibit differential dominant negative effects on development. Plant Cell 16, 2984-3001.
27. Hancock, R.D.V., R. (2005). Biosynthesis and Catabolism of L-Ascorbic Acid in Plants. Critical Reviews in Plant Scienced 24, 167-188.
28. Hemavathi, Upadhyaya, C.P., Akula, N., Young, K.E., Chun, S.C., Kim, D.H., and Park, S.W. (2010). Enhanced ascorbic acid accumulation in transgenic potato confers tolerance to various abiotic stresses. Biotechnol Lett 32, 321-330.
29. Hieta, R., and Myllyharju, J. (2002). Cloning and characterization of a low molecular weight prolyl 4-hydroxylase from Arabidopsis thaliana. Effective hydroxylation of proline-rich, collagen-like, and hypoxia-inducible transcription factor alpha-like peptides. J Biol Chem 277, 23965-23971.
30. Horemans, N., Foyer, C.H., and Asard, H. (2000). Transport and action of ascorbate at the plantplasma membrane. Trends Plant Sci 5, 263-267.
31. Imai, T., Karita, S., Shiratori, G., Hattori, M., Nunome, T., Oba, K., and Hirai, M. (1998). L-galactono-gamma-lactone dehydrogenase from sweet potato: purification and cDNA sequence analysis. Plant Cell Physiol 39, 1350-1358.
32. Ioannidi, E., Kalamaki, M.S., Engineer, C., Pateraki, I., Alexandrou, D., Mellidou, I., Giovannonni, J., and Kanellis, A.K. (2009). Expression profiling of ascorbic acid-related genes during tomato fruit development and ripening and in response to stress conditions. J Exp Bot 60, 663-678.
33. Ishikawa, T., and Shigeoka, S. (2008). Recent advances in ascorbate biosynthesis and the physiological significance of ascorbate peroxidase in photosynthesizing organisms. Biosci Biotechnol Biochem 72, 1143-1154.
34. Kato, J.Y., and Yoneda-Kato, N. (2009). Mammalian COP9 signalosome. Genes Cells 14, 1209-1225.
35. Keller, R., Renz, F.S., and Kossmann, J. (1999). Antisense inhibition of the GDP-mannose pyrophosphorylase reduces the ascorbate content in transgenic plants leading to developmental changes during senescence. Plant J 19, 131-141.
36. Kwok, S.F., Solano, R., Tsuge, T., Chamovitz, D.A., Ecker, J.R., Matsui, M., and Deng, X.W. (1998). Arabidopsis homologs of a c-Jun coactivator are present both in monomeric form and in the COP9 complex, and their abundance is differentially affected by the pleiotropic cop/det/fus mutations. Plant Cell 10, 1779-1790.
37. Laing, W.A., Bulley, S., Wright, M., Cooney, J., Jensen, D., Barraclough, D., and MacRae, E. (2004). A highly specific L-galactose-1-phosphate phosphatase on the path to ascorbate biosynthesis. Proc Natl Acad Sci U S A 101, 16976-16981.
38. Laing, W.A., Wright, M.A., Cooney, J., and Bulley, S.M. (2007). The missing step of the L-galactose pathway of ascorbate biosynthesis in plants, an L-galactose guanyltransferase, increases leaf ascorbate content. Proc Natl Acad Sci U S A 104, 9534-9539.
39. Li, L., and Deng, X.W. (2003). The COP9 signalosome: an alternative lid for the 26S proteasome? Trends Cell Biol 13, 507-509.
40. Lin, L.S., and Varner, J.E. (1991). Expression of Ascorbic Acid Oxidase in Zucchini Squash (Cucurbita pepo L.). Plant Physiol 96, 159-165.
41. Liu, Y., Shah, S.V., Xiang, X., Wang, J., Deng, Z.B., Liu, C., Zhang, L., Wu, J., Edmonds, T., Jambor, C., et al. (2009). COP9-associated CSN5 regulates exosomal protein deubiquitination and sorting. Am J Pathol 174, 1415-1425.
42. Loewus, F.A. (1999). Biosynthesis and metabolism of ascorbic acid in plants and of analogs of ascorbic acid in fungi. Phytochemistry 52, 193-210.
43. Lorence, A., Chevone, B.I., Mendes, P., and Nessler, C.L. (2004). myo-inositol oxygenase offers a possible entry point into plant ascorbate biosynthesis. Plant Physiol 134, 1200-1205.
44. Lukowitz, W., Nickle, T.C., Meinke, D.W., Last, R.L., Conklin, P.L., and Somerville, C.R. (2001). Arabidopsis cyt1 mutants are deficient in a mannose-1-phosphate guanylyltransferase and point to arequirement of N-linked glycosylation for cellulose biosynthesis. Proc Natl Acad Sci U S A 98, 2262-2267.
45. Maruta, T., Yonemitsu, M., Yabuta, Y., Tamoi, M., Ishikawa, T., and Shigeoka, S. (2008). Arabidopsis phosphomannose isomerase 1, but not phosphomannose isomerase 2, is essential for ascorbic acid biosynthesis. J Biol Chem 283, 28842-28851.
46. Muller, P., Li, X.P., and Niyogi, K.K. (2001). Non-photochemical quenching. A response to excess light energy. Plant Physiol 125, 1558-1566.
47. Mundt, K.E., Liu, C., and Carr, A.M. (2002). Deletion mutants in COP9/signalosome subunits in fission yeast Schizosaccharomyces pombe display distinct phenotypes. Mol Biol Cell 13, 493-502.
48. Naumann M , B.-O.D., Huang X,Ferrell K,Dubiel W (1999). COP9 signalosome-directed c-Jun activation/stabilization is independent of JNK. J Biol Chem 274, 35297-35300.
49. Ning Wei, G.S.a.X.-W.D. (2008). The COP9 signalosome: more than a protease. Trends in Biochemical Sciences 33, 592-600.
50. Noctor, G., and Foyer, C.H. (1998). ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under Control. Annu Rev Plant Physiol Plant Mol Biol 49, 249-279.
51. Oh, W., Lee, E.W., Sung, Y.H., Yang, M.R., Ghim, J., Lee, H.W., and Song, J. (2006). Jab1 induces the cytoplasmic localization and degradation of p53 in coordination with Hdm2. J Biol Chem 281, 17457-17465.
52. Oron, E., Mannervik, M., Rencus, S., Harari-Steinberg, O., Neuman-Silberberg, S., Segal, D., and Chamovitz, D.A. (2002). COP9 signalosome subunits 4 and 5 regulate multiple pleiotropic pathways in Drosophila melanogaster. Development 129, 4399-4409.
53. Pastori, G.M., Kiddle, G., Antoniw, J., Bernard, S., Veljovic-Jovanovic, S., Verrier, P.J., Noctor, G., and Foyer, C.H. (2003). Leaf vitamin C contents modulate plant defense transcripts and regulate genes that control development through hormone signaling. Plant Cell 15, 939-951.
54. Peth, A., Berndt, C., Henke, W., and Dubiel, W. (2007). Downregulation of COP9 signalosome subunits differentially affects the CSN complex and target protein stability. BMC Biochem 8, 27.
55. Pignocchi, C., Fletcher, J.M., Wilkinson, J.E., Barnes, J.D., and Foyer, C.H. (2003). The function of ascorbate oxidase in tobacco. Plant Physiol 132, 1631-1641.
56. Pignocchi, C., and Foyer, C.H. (2003). Apoplastic ascorbate metabolism and its role in the regulation of cell signalling. Curr Opin Plant Biol 6, 379-389.
57. Richardson, A.C. (2004). High growing temperatures reduce fruit carbohydrate and vitamin C in kiwifruit. Plant Cell and Environment 27, 423-435.
58. Sharon, M., Mao, H., Boeri Erba, E., Stephens, E., Zheng, N., and Robinson, C.V. (2009). Symmetrical modularity of the COP9 signalosome complex suggests its multifunctionality. Structure 17, 31-40.
59. Smirnoff, N. (2000). Ascorbate biosynthesis and function in photoprotection. Philos Trans R Soc Lond B Biol Sci 355, 1455-1464.
60. Smirnoff, N., and Pallanca, J.E. (1996). Ascorbate metabolism in relation to oxidative stress.Biochem Soc Trans 24, 472-478.
61. Tabata, K., Oba, K., Suzuki, K., and Esaka, M. (2001). Generation and properties of ascorbic acid-deficient transgenic tobacco cells expressing antisense RNA for L-galactono-1,4-lactone dehydrogenase. Plant J 27, 139-148.
62. Tabata, K., Takaoka, T., and Esaka, M. (2002). Gene expression of ascorbic acid-related enzymes in tobacco. Phytochemistry 61, 631-635.
63. Tamaoki, M. (2003). Light-controlled expression of a gene encoding L-galactono-lactone dehydrogenase which affects ascorbate pool size in Arabidopsis thaliana. Plant Sci 16, 1111-1117.
64. Tanguy, G., Drevillon, L., Arous, N., Hasnain, A., Hinzpeter, A., Fritsch, J., Goossens, M., and Fanen, P. (2008). CSN5 binds to misfolded CFTR and promotes its degradation. Biochim Biophys Acta 1783, 1189-1199.
65. Tomoda, K., Kato, J.Y., Tatsumi, E., Takahashi, T., Matsuo, Y., and Yoneda-Kato, N. (2005). The Jab1/COP9 signalosome subcomplex is a downstream mediator of Bcr-Abl kinase activity and facilitates cell-cycle progression. Blood 105, 775-783.
66. Wang, X., Li, W., Piqueras, R., Cao, K., Deng, X.W., and Wei, N. (2009). Regulation of COP1 nuclear localization by the COP9 signalosome via direct interaction with CSN1. Plant J 58, 655-667.
67. Wang, Z., Xiao, Y., Chen, W., Tang, K., and Zhang, L. (2010). Increased vitamin C content accompanied by an enhanced recycling pathway confers oxidative stress tolerance in Arabidopsis. J Integr Plant Biol 52, 400-409.
68. Wei, N., and Deng, X.W. (1992). COP9: a new genetic locus involved in light-regulated development and gene expression in arabidopsis. Plant Cell 4, 1507-1518.
69. Wei, N., and Deng, X.W. (2003). The COP9 signalosome. Annu Rev Cell Dev Biol 19, 261-286.
70. Wheeler, G.L., Jones, M.A., and Smirnoff, N. (1998). The biosynthetic pathway of vitamin C in higher plants. Nature 393, 365-369.
71. Wolucka, B.A., and Van Montagu, M. (2003). GDP-mannose 3',5'-epimerase forms GDP-L-gulose, a putative intermediate for the de novo biosynthesis of vitamin C in plants. J Biol Chem 278, 47483-47490.
72. Yabuta, Y., Mieda, T., Rapolu, M., Nakamura, A., Motoki, T., Maruta, T., Yoshimura, K., Ishikawa, T., and Shigeoka, S. (2007). Light regulation of ascorbate biosynthesis is dependent on the photosynthetic electron transport chain but independent of sugars in Arabidopsis. J Exp Bot 58, 2661-2671.
73. Yahalom, A., Kim, T.H., Roy, B., Singer, R., von Arnim, A.G., and Chamovitz, D.A. (2008). Arabidopsis eIF3e is regulated by the COP9 signalosome and has an impact on development and protein translation. Plant J 53, 300-311.
74. Yin, L., Wang, S., Eltayeb, A.E., Uddin, M.I., Yamamoto, Y., Tsuji, W., Takeuchi, Y., and Tanaka, K. (2010). Overexpression of dehydroascorbate reductase, but not monodehydroascorbate reductase, confers tolerance to aluminum stress in transgenic tobacco. Planta 231, 609-621.
2. Arrigoni, O. (1994). Ascorbate system in plant development. J Bioenerg Biomembr 26, 407-419.
3. Barth, C., De Tullio, M., and Conklin, P.L. (2006). The role of ascorbic acid in the control of flowering time and the onset of senescence. J Exp Bot 57, 1657-1665.
4. Bartoli, C.G., Yu, J., Gomez, F., Fernandez, L., McIntosh, L., and Foyer, C.H. (2006). Inter-relationships between light and respiration in the control of ascorbic acid synthesis and accumulation in Arabidopsis thaliana leaves. J Exp Bot 57, 1621-1631.
5. Brunhuber, N.M., Mort, J.L., Christoffersen, R.E., and Reich, N.O. (2000). Steady-state kinetic mechanism of recombinant avocado ACC oxidase: initial velocity and inhibitor studies. Biochemistry 39, 10730-10738.
6. Burger-Kentischer, A., Finkelmeier, D., Thiele, M., Schmucker, J., Geiger, G., Tovar, G.E., and Bernhagen, J. (2005). Binding of JAB1/CSN5 to MIF is mediated by the MPN domain but is independent of the JAMM motif. FEBS Lett 579, 1693-1701.
7. Chamovitz, D.A., Wei, N., Osterlund, M.T., von Arnim, A.G., Staub, J.M., Matsui, M., and Deng, X.W. (1996). The COP9 complex, a novel multisubunit nuclear regulator involved in light control of a plant developmental switch. Cell 86, 115-121.
8. Chatterjee, I.B. (1973). Evolution and the biosynthesis of ascorbic acid. Science 182, 1271-1272.
9. Chen, Z., and Gallie, D.R. (2004). The ascorbic acid redox state controls guard cell signaling and stomatal movement. Plant Cell 16, 1143-1162.
10. Chen, Z., Young, T.E., Ling, J., Chang, S.C., and Gallie, D.R. (2003). Increasing vitamin C content of plants through enhanced ascorbate recycling. Proc Natl Acad Sci U S A 100, 3525-3530.
11. Conklin, P.L. (2004). Ascorbic acid, a familiar small molecule intertwined in the response of plants to ozone, pathogens, and the onset of senescence. Plant Cell and Environment 27, 959-960.
12. Conklin, P.L., Norris, S.R., Wheeler, G.L., Williams, E.H., Smirnoff, N., and Last, R.L. (1999). Genetic evidence for the role of GDP-mannose in plant ascorbic acid (vitamin C) biosynthesis. Proc Natl Acad Sci U S A 96, 4198-4203.
13. Cope, G.A., Suh, G.S., Aravind, L., Schwarz, S.E., Zipursky, S.L., Koonin, E.V., and Deshaies, R.J. (2002). Role of predicted metalloprotease motif of Jab1/Csn5 in cleavage of Nedd8 from Cul1. Science 298, 608-611.
14. Damoc, E., Fraser, C.S., Zhou, M., Videler, H., Mayeur, G.L., Hershey, J.W., Doudna, J.A., Robinson, C.V., and Leary, J.A. (2007). Structural characterization of the human eukaryotic initiation factor 3 protein complex by mass spectrometry. Mol Cell Proteomics 6, 1135-1146.
15. Daniel, A.C. (2009). Revisiting the COP9 signalosome as a transcriptional regulator. EMBO J 10,352-358.
16. DeBolt, S., Cook, D.R., and Ford, C.M. (2006). L-tartaric acid synthesis from vitamin C in higher plants. Proc Natl Acad Sci U S A 103, 5608-5613.
17. Deshaies, R.J., and Meyerowitz, E. (2000). COP1 patrols the night beat. Nat Cell Biol 2, E102-104.
18. Dohmann, E.M., Kuhnle, C., and Schwechheimer, C. (2005). Loss of the CONSTITUTIVE PHOTOMORPHOGENIC9 signalosome subunit 5 is sufficient to cause the cop/det/fus mutant phenotype in Arabidopsis. Plant Cell 17, 1967-1978.
19. Dowdle, J., Ishikawa, T., Gatzek, S., Rolinski, S., and Smirnoff, N. (2007). Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability. Plant J 52, 673-689.
20. Dutilleul, C., Garmier, M., Noctor, G., Mathieu, C., Chetrit, P., Foyer, C.H., and de Paepe, R. (2003). Leaf mitochondria modulate whole cell redox homeostasis, set antioxidant capacity, and determine stress resistance through altered signaling and diurnal regulation. Plant Cell 15, 1212-1226.
21. Fukumoto, A., Tomoda, K., Kubota, M., Kato, J.Y., and Yoneda-Kato, N. (2005). Small Jab1-containing subcomplex is regulated in an anchorage- and cell cycle-dependent manner, which is abrogated by ras transformation. FEBS Lett 579, 1047-1054.
22. Fukunaga, K., Fujikawa, Y., and Esaka, M. (2010). Light Regulation of Ascorbic Acid Biosynthesis in Rice via Light Responsive cis-Elements in Genes Encoding Ascorbic Acid Biosynthetic Enzymes. Biosci Biotechnol Biochem 74, 90929-90921-90924.
23. Gatzek, S., Wheeler, G.L., and Smirnoff, N. (2002). Antisense suppression of l-galactose dehydrogenase in Arabidopsis thaliana provides evidence for its role in ascorbate synthesis and reveals light modulated l-galactose synthesis. Plant J 30, 541-553.
24. Grace, S.C., and Logan, B.A. (1996). Acclimation of Foliar Antioxidant Systems to Growth Irradiance in Three Broad-Leaved Evergreen Species. Plant Physiol 112, 1631-1640.
25. Green, M.A., and Fry, S.C. (2005). Vitamin C degradation in plant cells via enzymatic hydrolysis of 4-O-oxalyl-L-threonate. Nature 433, 83-87.
26. Gusmaroli, G., Feng, S., and Deng, X.W. (2004). The Arabidopsis CSN5A and CSN5B subunits are present in distinct COP9 signalosome complexes, and mutations in their JAMM domains exhibit differential dominant negative effects on development. Plant Cell 16, 2984-3001.
27. Hancock, R.D.V., R. (2005). Biosynthesis and Catabolism of L-Ascorbic Acid in Plants. Critical Reviews in Plant Scienced 24, 167-188.
28. Hemavathi, Upadhyaya, C.P., Akula, N., Young, K.E., Chun, S.C., Kim, D.H., and Park, S.W. (2010). Enhanced ascorbic acid accumulation in transgenic potato confers tolerance to various abiotic stresses. Biotechnol Lett 32, 321-330.
29. Hieta, R., and Myllyharju, J. (2002). Cloning and characterization of a low molecular weight prolyl 4-hydroxylase from Arabidopsis thaliana. Effective hydroxylation of proline-rich, collagen-like, and hypoxia-inducible transcription factor alpha-like peptides. J Biol Chem 277, 23965-23971.
30. Horemans, N., Foyer, C.H., and Asard, H. (2000). Transport and action of ascorbate at the plantplasma membrane. Trends Plant Sci 5, 263-267.
31. Imai, T., Karita, S., Shiratori, G., Hattori, M., Nunome, T., Oba, K., and Hirai, M. (1998). L-galactono-gamma-lactone dehydrogenase from sweet potato: purification and cDNA sequence analysis. Plant Cell Physiol 39, 1350-1358.
32. Ioannidi, E., Kalamaki, M.S., Engineer, C., Pateraki, I., Alexandrou, D., Mellidou, I., Giovannonni, J., and Kanellis, A.K. (2009). Expression profiling of ascorbic acid-related genes during tomato fruit development and ripening and in response to stress conditions. J Exp Bot 60, 663-678.
33. Ishikawa, T., and Shigeoka, S. (2008). Recent advances in ascorbate biosynthesis and the physiological significance of ascorbate peroxidase in photosynthesizing organisms. Biosci Biotechnol Biochem 72, 1143-1154.
34. Kato, J.Y., and Yoneda-Kato, N. (2009). Mammalian COP9 signalosome. Genes Cells 14, 1209-1225.
35. Keller, R., Renz, F.S., and Kossmann, J. (1999). Antisense inhibition of the GDP-mannose pyrophosphorylase reduces the ascorbate content in transgenic plants leading to developmental changes during senescence. Plant J 19, 131-141.
36. Kwok, S.F., Solano, R., Tsuge, T., Chamovitz, D.A., Ecker, J.R., Matsui, M., and Deng, X.W. (1998). Arabidopsis homologs of a c-Jun coactivator are present both in monomeric form and in the COP9 complex, and their abundance is differentially affected by the pleiotropic cop/det/fus mutations. Plant Cell 10, 1779-1790.
37. Laing, W.A., Bulley, S., Wright, M., Cooney, J., Jensen, D., Barraclough, D., and MacRae, E. (2004). A highly specific L-galactose-1-phosphate phosphatase on the path to ascorbate biosynthesis. Proc Natl Acad Sci U S A 101, 16976-16981.
38. Laing, W.A., Wright, M.A., Cooney, J., and Bulley, S.M. (2007). The missing step of the L-galactose pathway of ascorbate biosynthesis in plants, an L-galactose guanyltransferase, increases leaf ascorbate content. Proc Natl Acad Sci U S A 104, 9534-9539.
39. Li, L., and Deng, X.W. (2003). The COP9 signalosome: an alternative lid for the 26S proteasome? Trends Cell Biol 13, 507-509.
40. Lin, L.S., and Varner, J.E. (1991). Expression of Ascorbic Acid Oxidase in Zucchini Squash (Cucurbita pepo L.). Plant Physiol 96, 159-165.
41. Liu, Y., Shah, S.V., Xiang, X., Wang, J., Deng, Z.B., Liu, C., Zhang, L., Wu, J., Edmonds, T., Jambor, C., et al. (2009). COP9-associated CSN5 regulates exosomal protein deubiquitination and sorting. Am J Pathol 174, 1415-1425.
42. Loewus, F.A. (1999). Biosynthesis and metabolism of ascorbic acid in plants and of analogs of ascorbic acid in fungi. Phytochemistry 52, 193-210.
43. Lorence, A., Chevone, B.I., Mendes, P., and Nessler, C.L. (2004). myo-inositol oxygenase offers a possible entry point into plant ascorbate biosynthesis. Plant Physiol 134, 1200-1205.
44. Lukowitz, W., Nickle, T.C., Meinke, D.W., Last, R.L., Conklin, P.L., and Somerville, C.R. (2001). Arabidopsis cyt1 mutants are deficient in a mannose-1-phosphate guanylyltransferase and point to arequirement of N-linked glycosylation for cellulose biosynthesis. Proc Natl Acad Sci U S A 98, 2262-2267.
45. Maruta, T., Yonemitsu, M., Yabuta, Y., Tamoi, M., Ishikawa, T., and Shigeoka, S. (2008). Arabidopsis phosphomannose isomerase 1, but not phosphomannose isomerase 2, is essential for ascorbic acid biosynthesis. J Biol Chem 283, 28842-28851.
46. Muller, P., Li, X.P., and Niyogi, K.K. (2001). Non-photochemical quenching. A response to excess light energy. Plant Physiol 125, 1558-1566.
47. Mundt, K.E., Liu, C., and Carr, A.M. (2002). Deletion mutants in COP9/signalosome subunits in fission yeast Schizosaccharomyces pombe display distinct phenotypes. Mol Biol Cell 13, 493-502.
48. Naumann M , B.-O.D., Huang X,Ferrell K,Dubiel W (1999). COP9 signalosome-directed c-Jun activation/stabilization is independent of JNK. J Biol Chem 274, 35297-35300.
49. Ning Wei, G.S.a.X.-W.D. (2008). The COP9 signalosome: more than a protease. Trends in Biochemical Sciences 33, 592-600.
50. Noctor, G., and Foyer, C.H. (1998). ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under Control. Annu Rev Plant Physiol Plant Mol Biol 49, 249-279.
51. Oh, W., Lee, E.W., Sung, Y.H., Yang, M.R., Ghim, J., Lee, H.W., and Song, J. (2006). Jab1 induces the cytoplasmic localization and degradation of p53 in coordination with Hdm2. J Biol Chem 281, 17457-17465.
52. Oron, E., Mannervik, M., Rencus, S., Harari-Steinberg, O., Neuman-Silberberg, S., Segal, D., and Chamovitz, D.A. (2002). COP9 signalosome subunits 4 and 5 regulate multiple pleiotropic pathways in Drosophila melanogaster. Development 129, 4399-4409.
53. Pastori, G.M., Kiddle, G., Antoniw, J., Bernard, S., Veljovic-Jovanovic, S., Verrier, P.J., Noctor, G., and Foyer, C.H. (2003). Leaf vitamin C contents modulate plant defense transcripts and regulate genes that control development through hormone signaling. Plant Cell 15, 939-951.
54. Peth, A., Berndt, C., Henke, W., and Dubiel, W. (2007). Downregulation of COP9 signalosome subunits differentially affects the CSN complex and target protein stability. BMC Biochem 8, 27.
55. Pignocchi, C., Fletcher, J.M., Wilkinson, J.E., Barnes, J.D., and Foyer, C.H. (2003). The function of ascorbate oxidase in tobacco. Plant Physiol 132, 1631-1641.
56. Pignocchi, C., and Foyer, C.H. (2003). Apoplastic ascorbate metabolism and its role in the regulation of cell signalling. Curr Opin Plant Biol 6, 379-389.
57. Richardson, A.C. (2004). High growing temperatures reduce fruit carbohydrate and vitamin C in kiwifruit. Plant Cell and Environment 27, 423-435.
58. Sharon, M., Mao, H., Boeri Erba, E., Stephens, E., Zheng, N., and Robinson, C.V. (2009). Symmetrical modularity of the COP9 signalosome complex suggests its multifunctionality. Structure 17, 31-40.
59. Smirnoff, N. (2000). Ascorbate biosynthesis and function in photoprotection. Philos Trans R Soc Lond B Biol Sci 355, 1455-1464.
60. Smirnoff, N., and Pallanca, J.E. (1996). Ascorbate metabolism in relation to oxidative stress.Biochem Soc Trans 24, 472-478.
61. Tabata, K., Oba, K., Suzuki, K., and Esaka, M. (2001). Generation and properties of ascorbic acid-deficient transgenic tobacco cells expressing antisense RNA for L-galactono-1,4-lactone dehydrogenase. Plant J 27, 139-148.
62. Tabata, K., Takaoka, T., and Esaka, M. (2002). Gene expression of ascorbic acid-related enzymes in tobacco. Phytochemistry 61, 631-635.
63. Tamaoki, M. (2003). Light-controlled expression of a gene encoding L-galactono-lactone dehydrogenase which affects ascorbate pool size in Arabidopsis thaliana. Plant Sci 16, 1111-1117.
64. Tanguy, G., Drevillon, L., Arous, N., Hasnain, A., Hinzpeter, A., Fritsch, J., Goossens, M., and Fanen, P. (2008). CSN5 binds to misfolded CFTR and promotes its degradation. Biochim Biophys Acta 1783, 1189-1199.
65. Tomoda, K., Kato, J.Y., Tatsumi, E., Takahashi, T., Matsuo, Y., and Yoneda-Kato, N. (2005). The Jab1/COP9 signalosome subcomplex is a downstream mediator of Bcr-Abl kinase activity and facilitates cell-cycle progression. Blood 105, 775-783.
66. Wang, X., Li, W., Piqueras, R., Cao, K., Deng, X.W., and Wei, N. (2009). Regulation of COP1 nuclear localization by the COP9 signalosome via direct interaction with CSN1. Plant J 58, 655-667.
67. Wang, Z., Xiao, Y., Chen, W., Tang, K., and Zhang, L. (2010). Increased vitamin C content accompanied by an enhanced recycling pathway confers oxidative stress tolerance in Arabidopsis. J Integr Plant Biol 52, 400-409.
68. Wei, N., and Deng, X.W. (1992). COP9: a new genetic locus involved in light-regulated development and gene expression in arabidopsis. Plant Cell 4, 1507-1518.
69. Wei, N., and Deng, X.W. (2003). The COP9 signalosome. Annu Rev Cell Dev Biol 19, 261-286.
70. Wheeler, G.L., Jones, M.A., and Smirnoff, N. (1998). The biosynthetic pathway of vitamin C in higher plants. Nature 393, 365-369.
71. Wolucka, B.A., and Van Montagu, M. (2003). GDP-mannose 3',5'-epimerase forms GDP-L-gulose, a putative intermediate for the de novo biosynthesis of vitamin C in plants. J Biol Chem 278, 47483-47490.
72. Yabuta, Y., Mieda, T., Rapolu, M., Nakamura, A., Motoki, T., Maruta, T., Yoshimura, K., Ishikawa, T., and Shigeoka, S. (2007). Light regulation of ascorbate biosynthesis is dependent on the photosynthetic electron transport chain but independent of sugars in Arabidopsis. J Exp Bot 58, 2661-2671.
73. Yahalom, A., Kim, T.H., Roy, B., Singer, R., von Arnim, A.G., and Chamovitz, D.A. (2008). Arabidopsis eIF3e is regulated by the COP9 signalosome and has an impact on development and protein translation. Plant J 53, 300-311.
74. Yin, L., Wang, S., Eltayeb, A.E., Uddin, M.I., Yamamoto, Y., Tsuji, W., Takeuchi, Y., and Tanaka, K. (2010). Overexpression of dehydroascorbate reductase, but not monodehydroascorbate reductase, confers tolerance to aluminum stress in transgenic tobacco. Planta 231, 609-621.