Biochemical characteristics of cyclobutane pyrimidine dimer photolyase and UV-B protecting mechanisms of mice (Oryza sativa L.)

环丁烷嘧啶二聚体光解酶的生化特性及小鼠UV-B防护机制（Oryza sativa L.）

基本信息

批准号：
12480154
负责人：
KUMAGAI Tadashi
金额：
$ 7.68万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

We made several new findings in the period of 2000 and 2002.1:UV-sensitive nice Norin 1 is deficient in photorepair of cyclobutane pyrimidine diners (CPDs). Using a photoflash approach, we showed that the deficiency in photorepair in vivo resulted from a structure/function alteration photolyase. These results were confirmed by studies with extracts, which showed that the Norin 1 photolyase-dimer complex was highly thermolabile relative to the UV-resistant Sasanishiki photolyase.2:CPD photolyase gene from Sasanishiki and Norin 1 were cloned and sequenced. They were found to encode an ORF for 506 amino acid residues. Amino acid at position 126 was glutamine in Sasanishiki, but was arginine in Norin 1.3:GST-fusion rice CPD photolyase was purified from E. coli KY20, and we determined FAD as one of the two chromophores.4:Dark-grown etiolated rice seedlings did hardly have CPD photolyase activity. The induction of CPD photolyase in dark-grown seedlings was under photocontrol of phytochrome, and the expression of photolyase gene was under photocontrol of phytochrome and/or cryptochrome.5:We started to produce a transgenic rice plant into which CPD photolyase gene was transformed using the Agrobacterium transformation system.6:The growth of near-isogenic line (NIL) of rice for purple leaf gene pl of rice with a genetic background of Taichung 65 (T-65) was significantly decreased relative to T-65 in the elevated UV-B during culture regardless of higher accumulation of UV-absorbing compounds and anthocyanins than T-65. The steady-state CPD levels in the NIL was also higher than that in T-65. We showed that the growth stunting and increase in CPD levels under chronic UV-B irradiated with visible light might be due to the difference in the screening effects of UV-B effective for producing CPD levels and blue/UV-A effective for CPD photolyase activity.

我们在2000年和2002.1期间做出了几个新发现：对紫外线敏感的NOTIN 1缺乏环丁烷嘧啶食客（CPDS）的照相板。使用Photoflash方法，我们表明了体内光pair的缺陷是由结构/功能改变光溶解酶引起的。通过提取物的研究证实了这些结果，这表明相对于耐紫外线的Sasanishiki光溶解酶，Norin 1光溶酶二聚体复合物是高度热的。发现它们用于506个氨基酸残基的ORF。位于126位的氨基酸是Sasanishiki中的谷氨酰胺，但在Norin 1.3中是精氨酸：GST融合米CPD光溶解酶从大肠杆菌Ky20纯化，我们确定了两种发色团之一的时尚。4：深层生长的稻草。确实没有CPD光溶解酶活性。在深色生长幼苗中CPD光溶解酶的诱导在植物色素的光能下，光溶基基因的表达在植物色素和/或加密色素的光能下。农业转化系统。6：含有泰顿65（T-65）遗传背景的紫色叶基因PL（T-65）的紫色叶基因PL的近乎异源线（NIL）的生长显着降低了相对于高架紫外线的T-65 -b在培养过程中，不论紫外线吸收化合物和花色苷的积累高于T-65。 NIL中的稳态CPD水平也高于T-65中的CPD水平。我们表明，在用可见光照射的慢性UV-B下，CPD水平的生长发育迟缓和增加的CPD水平增加可能是由于UV-B有效产生CPD水平的筛选效应的差异以及对CPD光解活动有效的蓝色/UV-A 。