Department of Biological Science, University of Tulsa, Tulsa, OK, USA.
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Universidade do Porto, Vairão, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
Curr Biol. 2022 Oct 10;32(19):4201-4214.e12. doi: 10.1016/j.cub.2022.08.013. Epub 2022 Aug 31.
Red coloration is a salient feature of the natural world. Many vertebrates produce red color by converting dietary yellow carotenoids into red ketocarotenoids via an unknown mechanism. Here, we show that two enzymes, cytochrome P450 2J19 (CYP2J19) and 3-hydroxybutyrate dehydrogenase 1-like (BDH1L), are sufficient to catalyze this conversion. In birds, both enzymes are expressed at the sites of ketocarotenoid biosynthesis (feather follicles and red cone photoreceptors), and genetic evidence implicates these enzymes in yellow/red color variation in feathers. In fish, the homologs of CYP2J19 and BDH1L are required for ketocarotenoid production, and we show that these enzymes are sufficient to produce ketocarotenoids in cell culture and when ectopically expressed in fish skin. Finally, we demonstrate that the red-cone-enriched tetratricopeptide repeat protein 39B (TTC39B) enhances ketocarotenoid production when co-expressed with CYP2J19 and BDH1L. The discovery of this mechanism of ketocarotenoid biosynthesis has major implications for understanding the evolution of color diversity in vertebrates.
红色是自然界的一个显著特征。许多脊椎动物通过一种未知的机制，将饮食中的黄色类胡萝卜素转化为红色酮类胡萝卜素来产生红色。在这里，我们表明两种酶，细胞色素 P450 2J19（CYP2J19）和 3-羟基丁酸脱氢酶 1 样（BDH1L），足以催化这种转化。在鸟类中，这两种酶都在酮类胡萝卜素生物合成的部位（羽毛滤泡和红色圆锥光感受器）表达，遗传证据表明这些酶与羽毛中的黄色/红色颜色变化有关。在鱼类中，CYP2J19 和 BDH1L 的同源物是酮类胡萝卜素产生所必需的，我们表明这些酶足以在细胞培养中和异位表达在鱼类皮肤中产生酮类胡萝卜素。最后，我们证明富含红色圆锥的四肽重复蛋白 39B（TTC39B）与 CYP2J19 和 BDH1L 共表达时会增强酮类胡萝卜素的产生。这种酮类胡萝卜素生物合成机制的发现对理解脊椎动物颜色多样性的进化具有重要意义。
