Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
Department of Biochemistry and Molecular Biology, Biocenter, University of Würzburg, Würzburg, 97074, Germany.
Nat Commun. 2019 Aug 9;10(1):3623. doi: 10.1038/s41467-019-11568-0.
Coordinated regulation of the lysosomal and autophagic systems ensures basal catabolism and normal cell physiology, and failure of either system causes disease. Here we describe an epigenetic rheostat orchestrated by c-MYC and histone deacetylases that inhibits lysosomal and autophagic biogenesis by concomitantly repressing the expression of the transcription factors MiT/TFE and FOXH1, and that of lysosomal and autophagy genes. Inhibition of histone deacetylases abates c-MYC binding to the promoters of lysosomal and autophagy genes, granting promoter occupancy to the MiT/TFE members, TFEB and TFE3, and/or the autophagy regulator FOXH1. In pluripotent stem cells and cancer, suppression of lysosomal and autophagic function is directly downstream of c-MYC overexpression and may represent a hallmark of malignant transformation. We propose that, by determining the fate of these catabolic systems, this hierarchical switch regulates the adaptive response of cells to pathological and physiological cues that could be exploited therapeutically.
溶酶体和自噬系统的协调调节确保了基础代谢和正常的细胞生理功能,而这两个系统的任何一个出现故障都会导致疾病。在这里,我们描述了一个由 c-MYC 和组蛋白去乙酰化酶协调的表观遗传变阻器,它通过同时抑制转录因子 MiT/TFE 和 FOXH1 的表达以及溶酶体和自噬基因的表达来抑制溶酶体和自噬的发生。组蛋白去乙酰化酶的抑制减弱了 c-MYC 与溶酶体和自噬基因启动子的结合,赋予了 MiT/TFE 成员 TFEB 和 TFE3 以及自噬调节剂 FOXH1 对启动子的占据。在多能干细胞和癌症中,溶酶体和自噬功能的抑制是 c-MYC 过表达的直接下游事件,可能代表恶性转化的一个标志。我们提出,通过决定这些分解代谢系统的命运,这种层次转换调节了细胞对病理和生理信号的适应性反应,这些反应可能具有治疗潜力。