More than a repair enzyme:: Aspergillus nidulans photolyase-like CryA is a regulator of sexual development
More than a repair enzyme:: Aspergillus nidulans photolyase-like CryA is a regulator of sexual development
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DOI：
10.1091/mbc.e08-01-0061
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发表时间：
2008-08-01
影响因子：
3.3
通讯作者：
Braus, Gerhard H.
中科院分区：
文献类型：
--
作者：
Bayram, Oezguer;Biesemann, Christoph;Braus, Gerhard H.
隐色素是一种蓝光受体，可能是从DNA光解酶蛋白家族进化而来的，许多生物体的基因组中都含有这两种分子的基因。这两种蛋白质结构彼此相似，这表明光控制和光保护有着共同的古老起源。然而，在丝状真菌细粒曲霉（Aspergillus nidulans）的基因组中，只鉴定出一个隐色素/光解酶编码基因，称为cryA。缺失cryA基因会在不适当的培养条件下引发性分化，并导致子实体形成调控因子的转录本上调。CryA是一种N端和c端合成的绿色荧光蛋白融合在细胞核内的蛋白。在UVA（350-370nm）光下，CryA在平板和深层培养中抑制性发育。引人注目的是，通过DNA修复缺陷大肠杆菌菌株的异源互补以及在a . nidulans uvsB Delta遗传背景中的过表达，证明了CryA具有光修复活性。这与单缺失的cryA δ菌株相反，后者对紫外线诱导的损伤没有表现出增加的敏感性。在a . nidulans中，cryA编码了一种新型的隐色素/光解酶，该酶在光依赖性发育和DNA修复活性中表现出调节功能。这代表了光分解酶和隐色素之间进化过渡的一个范例。
Cryptochromes are blue-light receptors that have presumably evolved from the DNA photolyase protein family, and the genomes of many organisms contain genes for both types of molecules. Both protein structures resemble each other, which suggests that light control and light protection share a common ancient origin. In the genome of the filamentous fungus Aspergillus nidulans, however, only one cryptochrome/photolyase-encoding gene, termed cryA, was identified. Deletion of the cryA gene triggers sexual differentiation under inappropriate culture conditions and results in upregulation of transcripts encoding regulators of fruiting body formation. CryA is a protein whose N- and C-terminal synthetic green fluorescent protein fusions localize to the nucleus. CryA represses sexual development under UVA(350-370nm) light both on plates and in submerged culture. Strikingly, CryA exhibits photorepair activity as demonstrated by heterologous complementation of a DNA repair-deficient Escherichia coli strain as well as overexpression in an A. nidulans uvsB Delta genetic background. This is in contrast to the single deletion cryA Delta strain, which does not show increased sensitivity toward UV-induced damage. In A. nidulans, cryA encodes a novel type of cryptochrome/photolyase that exhibits a regulatory function during light-dependent development and DNA repair activity. This represents a paradigm for the evolutionary transition between photolyases and cryptochromes.