In Vivo Dissection of the Intrinsically Disordered Receptor Domain of Tim23
In Vivo Dissection of the Intrinsically Disordered Receptor Domain of Tim23
复制标题
DOI：
10.1016/j.jmb.2020.03.031
复制
发表时间：
2020-05-01
影响因子：
5.6
通讯作者：
Mokranjac, Dejana
中科院分区：
文献类型：
--
作者：
Guensel, Umut;Paz, Eyal;Mokranjac, Dejana
在线粒体的膜间隙（IMS）中，Tim23的受体结构域在数百种不同蛋白质分别通过外膜和内膜中的TOM和TIM23复合物从胞质溶胶易位期间具有重要作用。这种本质上无序的结构域，甚至可以延伸到胞质溶胶中，被证明，主要是在体外，与TOM和TIM 23复合物的几个亚基相互作用。为了从分子水平上了解IMS中的组织中心，我们在体内解剖了Tim23的IMS结构域。我们发现，Tim23与Tim50的相互作用表面比以前认为的更大，并揭示了一个意想不到的相互作用的Tim23与Pam17在IMS中，损害的影响，他们在矩阵中的相互作用。此外，突变的两个保守的带负电荷的残基的Tim23，靠近内膜，阻止二聚化的Tim23。同样的突变增加了Tim23在线粒体表面的暴露，而膜电位的耗散降低了它。我们的研究结果揭示了一个复杂的网络Tim23在IMS中的相互作用，其影响是跨两个线粒体膜转导，确保有效的蛋白质易位到线粒体。(C)2020作者（S）出版社：Elsevier Ltd
In the intermembrane space (IMS) of mitochondria, the receptor domain of Tim23 has an essential role during translocation of hundreds of different proteins from the cytosol via the TOM and TIM23 complexes in the outer and inner membranes, respectively. This intrinsically disordered domain, which can even extend into the cytosol, was shown, mostly in vitro, to interact with several subunits of the TOM and TIM23 complexes. To obtain molecular understanding of this organizational hub in the IMS, we dissected the IMS domain of Tim23 in vivo. We show that the interaction surface of Tim23 with Tim50 is larger than previously thought and reveal an unexpected interaction of Tim23 with Pam17 in the IMS, impairment of which influences their interaction in the matrix. Furthermore, mutations of two conserved negatively charged residues of Tim23, close to the inner membrane, prevented dimerization of Tim23. The same mutations increased exposure of Tim23 on the mitochondrial surface, whereas dissipation of membrane potential decreased it. Our results reveal an intricate network of Tim23 interactions in the IMS, whose influence is transduced across two mitochondrial membranes, ensuring efficient translocation of proteins into mitochondria. (C) 2020 The Author(s). Published by Elsevier Ltd.