FERRITIN GENE-TRANSCRIPTION IS REGULATED BY IRON IN SOYBEAN CELL-CULTURES
FERRITIN GENE-TRANSCRIPTION IS REGULATED BY IRON IN SOYBEAN CELL-CULTURES
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DOI：
10.1073/pnas.88.18.8222
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发表时间：
1991-09-01
影响因子：
11.1
通讯作者：
BRIAT, JF
中科院分区：
文献类型：
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作者：
LESCURE, AM;PROUDHON, D;BRIAT, JF
铁调节的铁蛋白在动物中的合成主要由翻译控制存储的mRNA;铁诱导的铁蛋白基因的转录，当它发生时，改变铁蛋白mRNA和蛋白质的亚基组成，并耦合到翻译控制。基于蛋白质序列的相似性，植物和动物中的铁蛋白从共同的祖先进化而来;然而，在C末端发生序列分歧;结构预测表明植物铁蛋白具有E-螺旋，其在马铁蛋白中在四聚体界面处形成大通道。在当代植物中，转运肽由铁蛋白mRNA编码以将蛋白质靶向质体。铁调节合成的铁蛋白在植物和动物似乎是非常不同的，因为铁蛋白的50- 60倍的增加，以前观察到诱导培养的大豆细胞中的铁，伴随着一个等效的积累杂交铁蛋白mRNA和增加铁蛋白基因的转录。铁诱导细胞的铁蛋白mRNA与大豆下胚轴的组成型铁蛋白mRNA是相同的。铁诱导的蛋白质正常转运到质体。动物铁蛋白结构的差异与各种铁储存功能（铁蛋白储备和解毒）相一致。相比之下，恒定的大豆铁蛋白，铁诱导的和组成的结构，再加上在植物中过量的铁的液泡存储的潜力表明，从存储的铁蛋白mRNA的铁蛋白的快速合成可能不需要在植物中的铁解毒。
Iron-regulated ferritin synthesis in animals is dominated by translational control of stored mRNA; iron-induced transcription of ferritin genes, when it occurs, changes the subunit composition of ferritin mRNA and protein and is coupled to translational control. Ferritins in plants and animals have evolved from a common progenitor, based on the similarity of protein sequence; however, sequence divergence occurs in the C termini; structure prediction suggests that plant ferritin has the E-helix, which, in horse ferritin, forms a large channel at the tetrameric interface. In contemporary plants, a transit peptide is encoded by ferritin mRNA to target the protein to plastids. Iron-regulated synthesis of ferritin in plants and animals appears to be very different since the 50- to 60-fold increases of ferritin protein, previously observed to be induced by iron in cultured soybean cells, is accompanied by an equivalent accumulation of hybridizable ferritin mRNA and by increased transcription of ferritin genes. Ferritin mRNA from iron-induced cells and the constitutive ferritin mRNA from soybean hypocotyls are identical. The iron-induced protein is translocated normally to plastids. Differences in animal ferritin structure coincide with the various iron storage functions (reserve for iron proteins and detoxification). In contrast, the constancy of structure of soybean ferritin, iron-induced and constitutive, coupled with the potential for vacuolar storage of excess iron in plants suggest that rapid synthesis of ferritin from a stored ferritin mRNA may not be needed in plants for detoxification of iron.