Zhang Hao, Cui Peng, Lin Lu, Shen Ping, Tang Bing, Huang Yu-Ping
Wuhan University, People's Republic of China.
Extremophiles. 2009 Jul;13(4):669-78. doi: 10.1007/s00792-009-0251-5. Epub 2009 May 16.
Although ubiquitous in all haloarchaea, little is known about the transcription and regulation of the haloarchaeal hsp70. The purpose of this study is to investigate the transcription of the haloarchaeal hsp70 gene in Natrinema sp. J7 under the temperature and osmotic stress. The hsp70 gene was found to be both temperature- and osmotic-induced, while the response of hsp70 to cold shock was stronger than that to heat shock. Western blot analysis corroborated the similar results at the level of Hsp70 protein. Northern blot and primer extension analyses indicated that the hsp70 was transcribed into a monocistronic transcript and the thermal stress had no effect on the transcription initiation sites choice. The deletion analyses showed that two putative elements, TATA-box (TTTAAAA) and BRE (AGTAAC) located -27 bp upstream of the transcription initiation site played an essential role for the basal transcription of P( hsp70 ). The results suggested that there are some special regulators of hsp70 gene in Natrinema sp. J7.
尽管热休克蛋白70（Hsp70）在所有嗜盐古菌中普遍存在，但关于嗜盐古菌Hsp70的转录和调控却知之甚少。本研究的目的是调查嗜盐古菌Hsp70基因在嗜盐嗜碱嗜盐放线菌（Natrinema sp.）J7中在温度和渗透胁迫下的转录情况。发现Hsp70基因受温度和渗透压诱导，并且Hsp70对冷休克的反应强于热休克。蛋白质免疫印迹分析在Hsp70蛋白水平上证实了类似结果。Northern印迹和引物延伸分析表明，Hsp70转录成单顺反子转录本，热应激对转录起始位点的选择没有影响。缺失分析表明，位于转录起始位点上游-27 bp处的两个推定元件，即TATA盒（TTTAAAA）和BRE（AGTAAC），对P（Hsp70）的基础转录起重要作用。结果表明，嗜盐嗜碱嗜盐放线菌J7中存在一些Hsp70基因的特殊调节因子。
