Target of rapamycin (TOR) is a protein kinase that coordinates metabolism with nutrient and energy availability in eukaryotes. TOR and its primary interactors, RAPTOR and LST8, have been remarkably evolutionarily static since they arose in the unicellular last common ancestor of plants, fungi, and animals, but the upstream regulatory mechanisms and downstream effectors of TOR signaling have evolved considerable diversity in these separate lineages. Here, I focus on the roles of exaptation and adaptation in the evolution of novel signaling axes in the TOR network in multicellular eukaryotes, concentrating especially on amino acid sensing, cell-cell signaling, and cell differentiation.

雷帕霉素靶标 (TOR) 是一种蛋白激酶，可在真核生物中协调代谢与营养和能量可用性。自从 TOR 及其主要相互作用因子 RAPTOR 和 LST8 在植物、真菌和动物的单细胞最后共同祖先中出现以来，它们在进化上一直非常稳定，但 TOR 信号的上游调节机制和下游效应因子在这些独立的细胞中进化出相当大的多样性血统。在这里，我重点关注扩展和适应在多细胞真核生物 TOR 网络中新信号轴进化中的作用，特别关注氨基酸传感、细胞间信号传导和细胞分化。