Optogenetic tools (OTs) operating in the far‐red and near‐infrared (NIR) region offer advantages for light‐controlling biological processes in deep tissues and spectral multiplexing with fluorescent probes and OTs acting in the visible range. However, many NIR OTs suffer from background activation in darkness. Through shortening linkers, we engineered a novel NIR OT, iLight2, which exhibits a significantly reduced background activity in darkness, thereby increasing the light‐to‐dark activation contrast. The resultant optimal configuration of iLight2 components suggests a molecular mechanism of iLight2 action. Using a biliverdin reductase knock‐out mouse model, we show that iLight2 exhibits advanced performance in mouse primary cells and deep tissues in vivo. Efficient light‐controlled cell migration in wound healing cellular model demonstrates the possibility of using iLight2 in therapy and, overall, positions it as a valuable addition to the NIR OT toolkit for gene transcription applications.

中文翻译：

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iLight2：一种用于低背景激活基因转录的近红外光遗传学工具

在远红和近红外 (NIR) 区域工作的光遗传学工具 (OT) 为深层组织中的光控制生物过程以及荧光探针和在可见光范围内作用的 OT 的光谱复用提供了优势。然而，许多 NIR OT 在黑暗中会受到背景激活的影响。通过缩短连接子，我们设计了一种新型近红外OT，即iLight2，它在黑暗中表现出显着降低的背景活性，从而增加了明暗激活对比度。由此产生的 iLight2 组件的最佳配置表明了 iLight2 作用的分子机制。使用胆绿素还原酶敲除小鼠模型，我们证明 iLight2 在小鼠原代细胞和深层组织中表现出先进的性能体内。伤口愈合细胞模型中高效的光控细胞迁移证明了在治疗中使用 iLight2 的可能性，并且总体而言，将其定位为基因转录应用的 NIR OT 工具包的有价值的补充。