Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.
Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany.
Nat Commun. 2024 Jun 20;15(1):5265. doi: 10.1038/s41467-024-49611-4.
Mitochondria require an extensive proteome to maintain a variety of metabolic reactions, and changes in cellular demand depend on rapid adaptation of the mitochondrial protein composition. The TOM complex, the organellar entry gate for mitochondrial precursors in the outer membrane, is a target for cytosolic kinases to modulate protein influx. DYRK1A phosphorylation of the carrier import receptor TOM70 at Ser91 enables its efficient docking and thus transfer of precursor proteins to the TOM complex. Here, we probe TOM70 phosphorylation in molecular detail and find that TOM70 is not a CK2 target nor import receptor for MIC19 as previously suggested. Instead, we identify TOM20 as a MIC19 import receptor and show off-target inhibition of the DYRK1A-TOM70 axis with the clinically used CK2 inhibitor CX4945 which activates TOM20-dependent import pathways. Taken together, modulation of DYRK1A signalling adapts the central mitochondrial protein entry gate via synchronization of TOM70- and TOM20-dependent import pathways for metabolic rewiring. Thus, DYRK1A emerges as a cytosolic surveillance kinase to regulate and fine-tune mitochondrial protein biogenesis.
线粒体需要一个广泛的蛋白质组来维持各种代谢反应,而细胞需求的变化取决于线粒体蛋白质组成的快速适应。TOM 复合物是外膜中线粒体前体进入细胞器的入口门,是细胞溶质激酶调节蛋白流入的靶标。载体导入受体 TOM70 的 DYRK1A 磷酸化在丝氨酸 91 处使其能够有效地对接,从而将前体蛋白转移到 TOM 复合物。在这里,我们详细探究了 TOM70 的磷酸化,发现 TOM70 既不是 CK2 的靶标,也不是 MIC19 的导入受体,如先前所述。相反,我们确定 TOM20 是 MIC19 的导入受体,并显示出临床上使用的 CK2 抑制剂 CX4945 对 DYRK1A-TOM70 轴的非靶向抑制作用,该抑制剂激活依赖 TOM20 的导入途径。总之,通过同步 TOM70 和 TOM20 依赖的导入途径,调节 DYRK1A 信号传导可适应中央线粒体蛋白进入门,以进行代谢重编程。因此,DYRK1A 作为一种细胞质监视激酶出现,以调节和微调线粒体蛋白质生物发生。