The mu-opioid receptor (MOR) regulates the neuronal pathways involved in pain, reward, and respiration. To increase our understanding of MOR's roles in these pathways, there is a need to detect opioids at cellular resolution. Here, we engineered an improved opioid-sensor, called M-SPOTIT2, which is 11x brighter than our previously engineered M-SPOTIT1.1. We engineered M-SPOTIT2 by adding the amino acids YNSH, located near the fluorophore of the enhanced green fluorescent protein, to the circular permuted green fluorescent protein in M-SPOTIT2. M-SPOTIT2 is 11x brighter than our previously engineered M-SPOTIT1.1 in HEK293T cell culture and 2.7x brighter in neuronal culture. M-SPOTIT2 will potentially be useful for the detection of opioids in cell culture for drug screening and the detection of opioids at cellular resolution in animal tissues. By using M-SPOTIT2, researchers can gain more understanding about the mechanisms of addiction, respiratory suppression, and pain-modulation involved in opioid signaling.

中文翻译：

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一种具有改进的荧光强度的基因编码传感器，用于以细胞分辨率检测阿片类药物

μ-阿片受体 (MOR) 调节参与疼痛、奖赏和呼吸的神经通路。为了增加我们对 MOR 在这些途径中的作用的理解，需要以细胞分辨率检测阿片类药物。在这里，我们设计了一种改进的阿片类药物传感器，称为 M-SPOTIT2，它比我们之前设计的 M-SPOTIT1.1 亮 11 倍。我们通过将位于增强型绿色荧光蛋白荧光团附近的氨基酸 YNSH 添加到 M-SPOTIT2 中的圆形置换绿色荧光蛋白来设计 M-SPOTIT2。M-SPOTIT2 在 HEK293T 细胞培养中比我们之前设计的 M-SPOTIT1.1 亮 11 倍，在神经元培养中亮 2.7 倍。M-SPOTIT2 将可能用于检测细胞培养物中的阿片类药物以进行药物筛选，以及在动物组织中以细胞分辨率检测阿片类药物。