An internal antisense RNA regulates expression of the photosynthesis gene isiA
An internal antisense RNA regulates expression of the photosynthesis gene isiA
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DOI：
10.1073/pnas.0600927103
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发表时间：
2006-05-02
影响因子：
11.1
通讯作者：
Wilde, A
中科院分区：
文献类型：
--
作者：
Dühring, U;Axmann, IM;Wilde, A
小调控非编码RNA存在于真核生物和原核生物中。这些RNA转录物中的大多数是与其靶RNA具有短且仅部分反义互补性的转编码RNA，其通过修饰mRNA稳定性和翻译来调节基因表达。相比之下，关于真细菌中顺式编码、完全互补的反义RNA功能的报道很少。蓝细菌通过表达IsiA（铁胁迫诱导蛋白A）来应对缺铁，IsiA在光系统I周围形成巨大的环状结构。在这里，我们表明，这一过程是由IsRR（铁应激抑制RNA），顺式编码的反义RNA转录的isiA非编码链。铁胁迫下IsrR的人工过表达导致IsiA-光系统I超复合物的数量大幅减少，而IsrR耗竭导致IsiA的过早表达。IsrR/isiA mRNA双链体的偶联降解似乎是一个可逆的开关，可以响应环境变化。IsrR是迄今为止已知的唯一一种调节光合作用组分的RNA。
Small regulatory noncoding RNAs exist in both eukaryotic and prokaryotic organisms. Most of these RNA transcripts are transencoded RNAs with short and only partial antisense complementarity to their target RNAs, which regulate gene expression by modifying mRNA stability and translation. In contrast, reports on the function of cis-encoded, perfectly complementary antisense RNAs in eubacteria are rare. Cyanobacteria respond to iron deficiency by expressing IsiA (iron stress-induced protein A), which forms a giant ring structure around photosystem I. Here, we show that this process is controlled by IsrR (iron stress-repressed RNA), a cis-encoded antisense RNA transcribed from the isiA noncoding strand. Artificial overexpression of IsrR under iron stress causes a strongly diminished number of IsiA-photosystem I supercomplexes, whereas IsrR depletion results in premature expression of IsiA. The coupled degradation of IsrR/isiA mRNA duplexes appears to be a reversible switch that can respond to environmental changes. IsrR is the only RNA known so far to regulate a photosynthesis component.