Permeability transition in human mitochondria persists in the absence of peripheral stalk subunits of ATP synthase
Permeability transition in human mitochondria persists in the absence of peripheral stalk subunits of ATP synthase
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DOI：
10.1073/pnas.1711201114
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发表时间：
2017-08-22
影响因子：
11.1
通讯作者：
Walker, John E.
中科院分区：
文献类型：
--
作者：
He, Jiuya;Carroll, Joe;Walker, John E.
钙离子可触发线粒体内膜的非特异性通道，即渗透性过渡孔（PTP）的打开，导致细胞器肿胀，破坏内膜和ATP合成，导致细胞死亡。通过亲环蛋白D介导的环孢素A可以抑制孔的打开。有人提出，孔与二聚体ATP合成酶和寡霉素敏感赋予蛋白（OSCP）有关，寡霉素敏感赋予蛋白是该酶外周柄的一个组成部分，提供了亲环蛋白D相互作用的位点。亚基b为外周茎提供了一个中心的α -螺旋结构，从酶的催化结构域的顶部附近延伸，并通过两个α -螺旋穿过酶的膜结构域。我们研究了亚基b和OSCP参与PTP的可能性，方法是产生克隆细胞hap1 - δ b和hap1 - δ OSCP，它们分别缺乏亚基b和OSCP的膜结构域，其中对应的基因ATP5F1和atp50被破坏。两种细胞系都保留了PTP的特性；因此，亚基b的膜结构域不参与PTP， OSCP不提供与亲环蛋白d相互作用的位点。膜亚基ATP6、ATP8和亚基c先前已被排除在可能参与PTP的可能性之外；因此，ATP合酶中能够参与孔形成的亚基只有e、f、g、胰岛素敏感组织中的糖尿病相关蛋白（DAPIT）和6.8 kda的蛋白脂。
The opening of a nonspecific channel, known as the permeability transition pore (PTP), in the innermembranes of mitochondria can be triggered by calcium ions, leading to swelling of the organelle, disruption of the inner membrane and ATP synthesis, and cell death. Pore opening can be inhibited by cyclosporin A mediated via cyclophilin D. It has been proposed that the pore is associated with the dimeric ATP synthase and the oligomycin sensitivity conferral protein (OSCP), a component of the enzyme's peripheral stalk, provides the site at which cyclophilin D interacts. Subunit b contributes a central alpha-helical structure to the peripheral stalk, extending from near the top of the enzyme's catalytic domain and crossing the membrane domain of the enzyme via two alpha-helices. We investigated the possible involvement of the subunit b and the OSCP in the PTP by generating clonal cells, HAP1-Delta b and HAP1-Delta OSCP, lacking the membrane domain of subunit b or the OSCP, respectively, in which the corresponding genes, ATP5F1 and ATP5O, had been disrupted. Both cell lines preserve the characteristic properties of the PTP; therefore, the membrane domain of subunit b does not contribute to the PTP, and the OSCP does not provide the site of interaction with cyclophilin D. The membrane subunits ATP6, ATP8, and subunit c have been eliminated previously from possible participation in the PTP; thus, the only subunits of ATP synthase that could participate in pore formation are e, f, g, diabetes-associated protein in insulin-sensitive tissues (DAPIT), and the 6.8-kDa proteolipid.