Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950.
Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 2024 Mar 12;121(11):e2317017121. doi: 10.1073/pnas.2317017121. Epub 2024 Mar 8.
Fluorescent proteins (FPs) are ubiquitous tools in research, yet their endogenous functions in nature are poorly understood. In this work, we describe a combination of functions for FPs in a clade of intertidal sea anemones whose FPs control a genetic color polymorphism together with the ability to combat oxidative stress. Focusing on the underlying genetics of a fluorescent green "Neon" color morph, we show that allelic differences in a single FP gene generate its strong and vibrant color, by increasing both molecular brightness and FP gene expression level. Natural variation in FP sequences also produces differences in antioxidant capacity. We demonstrate that these FPs are strong antioxidants that can protect live cells against oxidative stress. Finally, based on structural modeling of the responsible amino acids, we propose a model for FP antioxidant function that is driven by molecular surface charge. Together, our findings shed light on the multifaceted functions that can co-occur within a single FP and provide a framework for studying the evolution of fluorescence as it balances spectral and physiological functions in nature.
荧光蛋白（FPs）是研究中无处不在的工具，但它们在自然界中的内源性功能却知之甚少。在这项工作中，我们描述了一组潮间带海葵的 FPs 的组合功能，它们的 FPs 控制着遗传颜色多态性，以及对抗氧化应激的能力。我们专注于一种荧光绿色“霓虹”颜色形态的基础遗传学，表明单个 FP 基因的等位基因差异通过增加分子亮度和 FP 基因表达水平来产生其强烈而充满活力的颜色。FP 序列的自然变异也产生了抗氧化能力的差异。我们证明这些 FPs 是强大的抗氧化剂，可以保护活细胞免受氧化应激。最后，基于负责氨基酸的结构建模，我们提出了一个 FP 抗氧化功能模型，该模型由分子表面电荷驱动。总之，我们的研究结果揭示了单个 FP 中可能同时存在的多方面功能，并为研究荧光作为平衡自然界中光谱和生理功能的进化提供了框架。
