Cardiolipin and mitochondrial cristae organization.
Cardiolipin and mitochondrial cristae organization.
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DOI：
10.1016/j.bbamem.2017.03.013
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发表时间：
2017-06
期刊：
影响因子：
--
通讯作者：
Ryan RO
中科院分区：
文献类型：
--
作者：
Ikon N;Ryan RO
细胞生物学中的一个基本问题是线粒体嵴的结构组织，已经研究了六十多年。长期以来，人们都知道嵴膜含有电子传递链蛋白，其完整性是建立驱动氧化磷酸化的质子梯度的关键。通过电子显微镜/断层扫描对嵴形态的可视化提供了证据，证明嵴是线粒体内膜（IM）的管状延伸，投射到基质空间中。将超微结构数据与 IM 的脂质成分相一致，为由圆顶形尖端覆盖的连续弯曲的圆柱形双层提供支持。由曲率施加的应变通过构成嵴膜的单层小叶中的磷脂的不对称分布来缓解。标志性线粒体脂质、心磷脂（IM 磷脂质量的~18%）和磷脂酰乙醇胺（34%）分离到面向嵴腔的负弯曲单层小叶，而相对的正弯曲、面向基质的单层小叶主要含有磷脂酰胆碱。与嵴相关的是许多蛋白质，它们以独特的方式发挥作用，以建立和/或维持其脂质库和结构完整性。通过将独特的脂质成分与一组蛋白质调节剂相结合，嵴膜采用并保持其特有的形态和功能特性。一旦建立，嵴超微结构对氧化磷酸化、细胞凋亡、融合/裂变以及能量代谢受损疾病有直接影响。
A fundamental question in cell biology, under investigation for over six decades, is the structural organization of mitochondrial cristae. Long known to harbor electron transport chain proteins, crista membrane integrity is key to establishment of the proton gradient that drives oxidative phosphorylation. Visualization of cristae morphology by electron microscopy / tomography has provided evidence that cristae are tube-like extensions of the mitochondrial inner membrane (IM) that project into the matrix space. Reconciling ultrastructural data with the lipid composition of the IM provides support for a continuously curved cylindrical bilayer capped by a dome-shaped tip. Strain imposed by the degree of curvature is relieved by an asymmetric distribution of phospholipids in monolayer leaflets that comprise cristae membranes. The signature mitochondrial lipid, cardiolipin (∼18 % of IM phospholipid mass), and phosphatidylethanolamine (34 %) segregate to the negatively curved monolayer leaflet facing the crista lumen while the opposing, positively curved, matrix-facing monolayer leaflet contains predominantly phosphatidylcholine. Associated with cristae are numerous proteins that function in distinctive ways to establish and/or maintain their lipid repertoire and structural integrity. By combining unique lipid components with a set of protein modulators, crista membranes adopt and maintain their characteristic morphological and functional properties. Once established, cristae ultrastructure has a direct impact on oxidative phosphorylation, apoptosis, fusion / fission as well as diseases of compromised energy metabolism.