Cristae are invaginations of the mitochondrial inner membrane that are crucial for cellular energy metabolism. The formation of cristae requires the presence of a protein complex known as MICOS, which is conserved across eukaryotic species. One of the subunits of this complex, MIC10, is a transmembrane protein that supports cristae formation by oligomerization. In Drosophila melanogaster, three MIC10-like proteins with different tissue-specific expression patterns exist. We demonstrate that CG41128/MINOS1b/DmMIC10b is the major MIC10 orthologue in flies. Its loss destabilizes MICOS, disturbs cristae architecture, and reduces the life span and fertility of flies. We show that DmMIC10b has a unique ability to polymerize into bundles of filaments, which can remodel mitochondrial crista membranes. The formation of these filaments relies on conserved glycine and cysteine residues, and can be suppressed by the co-expression of other Drosophila MICOS proteins. These findings provide new insights into the regulation of MICOS in flies, and suggest potential mechanisms for the maintenance of mitochondrial ultrastructure.

中文翻译：

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果蝇 MIC10b 可以聚合成嵴形状的细丝。

嵴是线粒体内膜的内陷，对于细胞能量代谢至关重要。嵴的形成需要一种称为 MICOS 的蛋白质复合物的存在，该蛋白质复合物在真核物种中是保守的。该复合物的亚基之一 MIC10 是一种跨膜蛋白，通过寡聚化支持嵴形成。在果蝇中，存在三种具有不同组织特异性表达模式的 MIC10 样蛋白。我们证明 CG41128/MINOS1b/DmMIC10b 是果蝇中主要的 MIC10 直系同源物。它的丧失会破坏 MICOS 的稳定性，扰乱嵴结构，并缩短果蝇的寿命和生育能力。我们证明 DmMIC10b 具有聚合成丝束的独特能力，可以重塑线粒体嵴膜。这些丝的形成依赖于保守的甘氨酸和半胱氨酸残基，并且可以通过其他果蝇MICOS 蛋白的共表达来抑制。这些发现为果蝇中 MICOS 的调节提供了新的见解，并提出了维持线粒体超微结构的潜在机制。