Light Control of hliA Transcription and Transcript Stability in the Cyanobacterium Synechococcus elongatus Strain PCC 7942
Light Control of hliA Transcription and Transcript Stability in the Cyanobacterium Synechococcus elongatus Strain PCC 7942
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蓝藻细长聚球藻菌株 PCC 7942 中 hliA 转录和转录稳定性的光控制
DOI：
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发表时间：
2004
影响因子：
3.2
通讯作者：
L. V. van Waasbergen
中科院分区：
文献类型：
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作者：
Kavitha Salem;L. V. van Waasbergen
摘要蓝藻的强光诱导蛋白（HLIPs）是一种保护细胞免受强光伤害的多肽。编码来自细长聚球藻菌株PCC 7942的HLIP的hliA基因响应于HL或低强度蓝光或UV-A光而表达。在这项研究中，我们通过北方分析探索了hliA基因在各种光照条件下的转录调节和转录稳定性的细节。HL或UV-A光转换后，hliA基因的转录水平急剧增加至相似水平，随后UV-A光迅速降低，但HL中没有，这与HL介导表达的早期阶段中的蓝色/UV-A光参与一致。低强度UV-A光的3分钟脉冲足以触发hliA mRNA积累，表明蓝色/UV-A光感受器参与该基因的上调。低强度的红光被发现会导致转录水平的轻微、短暂的增加（增加了红光感光细胞参与的可能性），而其他质量的光则没有明显的影响。没有证据表明HL或UV-A光诱导的hliA转录水平的波长特异性衰减。转录衰变在黑暗中有所减缓，当光合电子传递被黑暗或DCMU处理抑制时，出现了一个较小的mRNA种类，可能代表一个衰变中间体，当mRNA衰变减慢时积累。有证据表明，光对hliA的上调主要是一种转录反应，但条件是导致核糖体在转录物上停滞（例如，向黑暗的转变）可以帮助稳定hliA mRNA并影响表达水平。
ABSTRACT The high-light-inducible proteins (HLIPs) of cyanobacteria are polypeptides involved in protecting the cells from high-intensity light (HL). The hliA gene encoding the HLIP from Synechococcus elongatus strain PCC 7942 is expressed in response to HL or low-intensity blue or UV-A light. In this study, we explore via Northern analysis details of the transcriptional regulation and transcript stability of the hliA gene under various light conditions. Transcript levels of the hliA gene increased dramatically upon a shift to HL or UV-A light to similar levels, followed by a rapid decrease in UV-A light, but not in HL, consistent with blue/UV-A light involvement in early stages of HL-mediated expression. A 3-min pulse of low-intensity UV-A light was enough to trigger hliA mRNA accumulation, indicating that a blue/UV-A photoreceptor is involved in upregulation of the gene. Low-intensity red light was found to cause a slight, transient increase in transcript levels (raising the possibility of red-light photoreceptor involvement), while light of other qualities had no apparent effect. No evidence was found for wavelength-specific attenuation of hliA transcript levels induced by HL or UV-A light. Transcript decay was slowed somewhat in darkness, and when photosynthetic electron transport was inhibited by darkness or treatment with DCMU, there appeared a smaller mRNA species that may represent a decay intermediate that accumulates when mRNA decay is slowed. Evidence suggests that upregulation of hliA by light is primarily a transcriptional response but conditions that cause ribosomes to stall on the transcript (e.g., a shift to darkness) can help stabilize hliA mRNA and affect expression levels.
影响因子：
2.9
作者：
Shu-Hsing Wu;J. Lagarias
通讯作者：
Shu-Hsing Wu;J. Lagarias
lrtA mRNA 的转录和转录后控制，lrtA 是聚球藻中的光抑制转录物。
影响因子：
7.4
作者：
Samartzidou,H;Widger,WR
通讯作者：
Widger,WR