Glutamyl-tRNA mediates a switch in RNA polymerase use during chloroplast biogenesis
Glutamyl-tRNA mediates a switch in RNA polymerase use during chloroplast biogenesis
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DOI：
10.1038/sj.embor.7400411
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发表时间：
2005-06-01
期刊：
影响因子：
7.7
通讯作者：
Tanaka, K
中科院分区：
文献类型：
--
作者：
Hanaoka, M;Kanamaru, K;Tanaka, K
高等植物的叶绿体基因由两种类型的 RNA 聚合酶转录，这两种酶由核基因组（NEP（核编码质体 RNA 聚合酶））或质体（PEP（质体编码质体 RNA 聚合酶））基因组编码。 NEP 在很大程度上负责早期叶绿体发育过程中管家基因的转录。随后的光依赖性叶绿体成熟伴随着 NEP 活性的抑制和 PEP 的激活。在这里，我们发现质体编码的谷氨酸转移RNA（其表达依赖于PEP）在体外直接结合并抑制NEP的转录活性。因此，质体 tRNA(Glu) 似乎在叶绿体发育过程中介导 RNA 聚合酶使用从 NEP 到 PEP 的转换。
Chloroplast genes of higher plants are transcribed by two types of RNA polymerase that are encoded by nuclear (NEP (nuclear-encoded plastid RNA polymerase)) or plastid (PEP (plastid-encoded plastid RNA polymerase)) genomes. NEP is largely responsible for the transcription of housekeeping genes during early chloroplast development. Subsequent light-dependent chloroplast maturation is accompanied by repression of NEP activity and activation of PEP. Here, we show that the plastid-encoded transfer RNA for glutamate, the expression of which is dependent on PEP, directly binds to and inhibits the transcriptional activity of NEP in vitro. The plastid tRNA(Glu) thus seems to mediate the switch in RNA polymerase usage from NEP to PEP during chloroplast development.