Böttinger Lena, Mårtensson Christoph U, Song Jiyao, Zufall Nicole, Wiedemann Nils, Becker Thomas
Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, D-79104 Freiburg, Germany.
Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany.
Mol Biol Cell. 2018 Apr 1;29(7):776-785. doi: 10.1091/mbc.E17-09-0555.
Mitochondria are the powerhouses of eukaryotic cells. The activity of the respiratory chain complexes generates a proton gradient across the inner membrane, which is used by the FF-ATP synthase to produce ATP for cellular metabolism. In baker's yeast, , the cytochrome complex (complex III) and cytochrome oxidase (complex IV) associate in respiratory chain supercomplexes. Iron-sulfur clusters (ISC) form reactive centers of respiratory chain complexes. The assembly of ISC occurs in the mitochondrial matrix and is essential for cell viability. The cysteine desulfurase Nfs1 provides sulfur for ISC assembly and forms with partner proteins the ISC-biogenesis desulfurase complex (ISD complex). Here, we report an unexpected interaction of the active ISD complex with the cytochrome complex and cytochrome oxidase. The individual deletion of complex III or complex IV blocks the association of the ISD complex with respiratory chain components. We conclude that the ISD complex binds selectively to respiratory chain supercomplexes. We propose that this molecular link contributes to coordination of iron-sulfur cluster formation with respiratory activity.
线粒体是真核细胞的动力源。呼吸链复合物的活性在内膜上产生质子梯度，F₀F₁ - ATP合酶利用该梯度为细胞代谢产生ATP。在面包酵母中，细胞色素bc₁复合物（复合物III）和细胞色素c氧化酶（复合物IV）存在于呼吸链超复合物中。铁硫簇（ISC）构成呼吸链复合物的反应中心。ISC的组装发生在线粒体基质中，对细胞活力至关重要。半胱氨酸脱硫酶Nfs1为ISC组装提供硫，并与伙伴蛋白形成ISC生物合成脱硫酶复合物（ISD复合物）。在此，我们报道了活性ISD复合物与细胞色素bc₁复合物和细胞色素c氧化酶之间意外的相互作用。复合物III或复合物IV的单独缺失会阻断ISD复合物与呼吸链组分的结合。我们得出结论，ISD复合物选择性地结合呼吸链超复合物。我们提出，这种分子联系有助于铁硫簇形成与呼吸活性的协调。
