Navarro E, Ruiz-Pérez V L, Torres-Martínez S
Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain.
Eur J Biochem. 2000 Feb;267(3):800-7. doi: 10.1046/j.1432-1327.2000.01058.x.
This work describes the isolation and characterization of crgA, a Mucor circinelloides gene, which has a dominant-positive effect on light-regulated carotenogenesis. The crgA gene was originally identified in a transformation experiment as a 3'-truncated open reading frame which caused carotenoid overaccumulation in the dark. The complete cloning and sequencing of crgA revealed that its putative product presented several recognizable structural domains: a RING-finger zinc binding domain near the N-terminus, a putative nuclear localization signal, two stretches of acidic amino acids, glutamine-rich regions and a putative isoprenylation motif. The expression of exogenous copies of the complete crgA gene or two different 3'-truncated versions, produced a similar dominant-positive effect on the light-inducible carotenogenesis of M. circinelloides. The presence of these exogenous sequences also caused a missregulation of the endogenous crgA gene, resulting in its overexpression. Collectively, these observations suggest that crgA is involved in the regulation of carotenoid biosynthesis by light.
这项工作描述了卷枝毛霉基因crgA的分离和特性，该基因对光调节的类胡萝卜素生成具有显性正向作用。crgA基因最初是在一项转化实验中作为一个3'端截短的开放阅读框被鉴定出来的，它在黑暗中导致类胡萝卜素过度积累。crgA的完整克隆和测序表明，其推定产物具有几个可识别的结构域：靠近N端的一个环状锌结合结构域、一个推定的核定位信号、两段酸性氨基酸序列、富含谷氨酰胺的区域以及一个推定的异戊二烯化基序。完整的crgA基因或两个不同的3'端截短版本的外源拷贝的表达，对卷枝毛霉的光诱导类胡萝卜素生成产生了类似的显性正向作用。这些外源序列的存在还导致了内源性crgA基因的失调，导致其过度表达。总的来说，这些观察结果表明crgA参与了光对类胡萝卜素生物合成的调节。
