Supramolecular organization of ATP synthase and protonic energy coupling

ATP合酶的超分子组织和质子能量耦合

• 批准号: 426717114
• 负责人: Professorin Dr. Karin Busch
• 金额: --
• 依托单位: Institut für Integrative Zellbiologie und Physiologie (IIZP)
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/426717114?language=en
• 关键词: Supramolecular; organization; ATP; synthase; protonic

Mitochondrial ATP synthase is an enzyme pivotal for mitochondrial and cellular physiology. Energy derived from oxidative metabolism is stored in a proton-motive force (PMF) across the inner membrane of the organelle. The ATP synthase (CV) harness the PMF to generate ATP but also contributes to maintain the PMF under unfavourable conditions. Human ATP synthase is a complex of 29 subunits (including the regulatory protein IF1). The rotary machine consists of a membrane part (F0) and membrane-extrinsic (F1) part linked by central and peripheral stalks. Mitochondrial F1FO ATP synthase is organized in dimers that form rows along the rims of cristae. This specific supramolecular structure also contributes to the formation and stabilization of the specific cristae architecture, next to the cristae-junction related protein complexes OPA1 and the MICOS complex. Functional and physical interaction between ATP synthase and OPA1, respectively MICOS compounds were reported, suggesting a crosstalk between the cristae-shaping proteins. The dimerization of ATP synthase is promoted by subunits e and g, while the subunit DAPIT/USMG5 is likely involved in dimer-dimer stabilization. Likewise, the inhibitory factor IF1 also promotes dimer-dimer interaction in addition to its ATP synthase activity-regulating function. We recently showed that also the spatiotemporal organization of ATP synthase and its mobility in cristae membranes is determined by IF1. In the upcoming funding period, we aim to better understand the relationship between the supramolecular organization of ATP synthase and its enzyme activity. To this end, we will manipulate the oligomerization of ATP synthase via changing concentrations of the DAPIT- and IF1 subunits. The effects of decreased CV oligomerization on enzyme activity will be measured in living cells using fluorescent biosensors for pH, m, and ATP. We hypothesize that disruption of oligomeric structure leads to enzyme instability and a shift toward ATP hydrolysis, likely also involving ultrastructural changes of cristae. This could be counterbalanced by upregulation of IF1. In collaboration with P02, we will study the crosstalk of DAPIT/ATP synthase with the MICOS complex, specifically the Mic10 subunit. Our cell lines will be made available for additional studies within the consortium (P05, P06, P07) to further investigate the crosstalk between supramolecular ATP organization and MICOS.

线粒体ATP合酶是线粒体和细胞生理学的关键酶。来自氧化代谢的能量储存在跨细胞器内膜的质子动力（PMF）中。ATP合成酶（CV）利用PMF产生ATP，但也有助于在不利条件下维持PMF。人类ATP合成酶是一个由29个亚基组成的复合物（包括调节蛋白IF 1）。旋转机械由膜部分（F0）和膜外部分（F1）组成，膜外部分由中心和外围柄连接。线粒体F1 FO ATP合酶以二聚体的形式组织，形成沿嵴边缘沿着排列的行。这种特定的超分子结构也有助于特定嵴结构的形成和稳定，与嵴连接相关的蛋白复合物OPA 1和MICOS复合物相邻。报道了ATP合酶和OPA 1，分别MICOS化合物之间的功能和物理相互作用，表明嵴形成蛋白之间的串扰。ATP合酶的二聚化由亚基e和g促进，而亚基DAPIT/USMG 5可能参与二聚体-二聚体稳定。同样地，抑制因子IF 1除了其ATP合酶活性调节功能外，还促进二聚体-二聚体相互作用。我们最近表明，也ATP合酶的时空组织和它的流动性在嵴膜是由IF 1。在即将到来的资助期间，我们的目标是更好地了解ATP合酶的超分子组织与其酶活性之间的关系。为此，我们将通过改变DAPIT和IF 1亚基的浓度来操纵ATP合酶的寡聚化。CV寡聚化降低对酶活性的影响将在活细胞中使用用于pH、pH和ATP的荧光生物传感器来测量。我们推测寡聚体结构的破坏导致酶的不稳定性和向ATP水解的转变，可能还涉及嵴的超微结构变化。这可以通过IF 1的上调来抵消。与P02合作，我们将研究DAPIT/ATP合酶与MICOS复合物，特别是Mic 10亚基的串扰。我们的细胞系将可用于联盟内的其他研究（P05，P06，P07），以进一步研究超分子ATP组织和MICOS之间的串扰。