Chlorophyll precursors are signals of chloroplast origin involved in light induction of nuclear heat-shock genes
Chlorophyll precursors are signals of chloroplast origin involved in light induction of nuclear heat-shock genes
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DOI：
10.1073/pnas.94.25.14168
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发表时间：
1997-12-09
影响因子：
11.1
通讯作者：
Beck, CF
中科院分区：
文献类型：
--
作者：
Kropat, J;Oster, U;Beck, CF
细胞器和细胞核的活动之间的协调需要信号的交换，利用衣原体，我们提供的证据表明，质体来源的叶绿素前体可能取代光诱导两个核热休克基因（HSP 70 A和HSP 70 B），从而有资格作为质体信号。突变体的合成缺陷的Mg-原卟啉IX不再诱导光。饲养的镁-原卟啉IX或其二甲酯的野生型或突变体细胞在黑暗中导致诱导。对对光有或没有反应的HSP 70 A启动子突变体的分析表明，这些叶绿素前体特异性地激活光信号通路。当加入原卟啉IX、原叶绿酸或叶绿酸时，未观察到基因表达的激活：表明了确定的叶绿素前体与调节核基因表达的因子的特异性相互作用。
Coordination between the activities of organelles and the nucleus requires the exchange of signals, Using Chlamydomonas, we provide evidence that plastid-derived chlorophyll precursors may replace light in the induction of two nuclear heat-shock genes (HSP70A and HSP70B) and thus qualify as plastidic signal. Mutants defective in the synthesis of Mg-protoporphyrin IX were no longer inducible by light. Feeding of Mg-protoporphyrin IX or its dimethyl ester to wild-type or mutant cells in the dark resulted in induction. The analysis of HSP70A promoter mutants that do or do not respond to light revealed that these chlorophyll precursors specifically activate the light signaling pathway. Activation of gene expression was not observed when protoporphyrin IX, protochlorphyllide, or chlorophyllide were added: A specific interaction of defined chlorophyll precursors with factor(s) that regulate nuclear gene expression is suggested.