Deciphering the functional interplay between mitochondrial inner membrane remodelling regulators and mitochondrial RNA granule integrity

破译线粒体内膜重塑调节剂与线粒体 RNA 颗粒完整性之间的功能相互作用

• 批准号: 465350547
• 负责人: Dr. Arun Kumar Kondadi
• 金额: --
• 依托单位: Institut für Biochemie und Molekularbiologie I
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/465350547?language=en
• 关键词: Deciphering; functional; interplay; between; mitochondrial

Mitochondria are vital double membrane-enclosed cellular organelles playing essential metabolic roles in eukaryotes. The inner membrane (IM) invaginates to form the cristae membrane (CM) and connects to the remaining IM (inner boundary membrane (IBM)) by crista junctions (CJs). CJs are roughly 25 nm slot-like structures which act as a diffusion barrier for proteins between CM and IBM. The MICOS complex enriched at the CJs comprises of seven different proteins. MIC26 and MIC27, which are part of the MICOS complex, belong to the apolipoprotein family. MIC26 and MIC27 are reciprocally regulated at the protein level i.e the levels of MIC26 increase upon depletion of MIC27 and vice versa. While studying the morphology of mitochondrial RNA granules (MRGs) using FASTKD2, we intriguingly found a total loss of FASTKD2 in the MRGs of cells specifically knocked out for both MIC26 and MIC27 (Double Knockouts (DKOs)). We also found MIC26 and MIC27 levels decreased and increased by half respectively in FASTKD2 knockouts (KOs) compared to control cells. Therefore, we would like to study the significance of such an interesting mutual regulation between MICOS apolipoproteins and FASTKD2, an MRG-associated protein. We will determine the possible mechanisms leading to such a mutual regulation. Further, we will decipher the nanoscale organisation of MIC26, MIC27 and FASTKD2 at the IM using STED super-resolution nanoscopy and mobility of the mentioned proteins in FASTKD2 KOs, MIC26 and MIC27 DKOs using FRAP technique. Last but not the least, we will determine the functional significance of the mutual regulation between MIC26, MIC27 present at the CJs on one hand and FASTKD2 associated with the MRGs on the other hand. In conclusion, we will contribute to understanding of a novel mechanism connecting mitochondrial RNA biology and IM remodelling which could plausibly explain the pathophysiology associated with these proteins.

线粒体是一种重要的双膜细胞器，在真核生物中起着重要的代谢作用。内膜（IM）内陷形成嵴膜（CM），并通过嵴连接（CJ）与剩余的IM（内界膜（IBM））连接。CJ是大约25 nm的槽状结构，其充当CM和IBM之间的蛋白质的扩散屏障。 在CJ处富集的MICOS复合物包含七种不同的蛋白质。MIC26和MIC27是MICOS复合物的一部分，属于载脂蛋白家族。MIC26和MIC27在蛋白质水平上受到调节，即MIC26的水平在MIC27耗尽时增加，反之亦然。在使用FASTKD 2研究线粒体RNA颗粒（MRG）的形态学时，我们有趣地发现，在特异性敲除MIC 26和MIC 27（双敲除（DKO））的细胞的MRG中FASTKD 2完全丢失。我们还发现，与对照细胞相比，FASTKD 2敲除（科斯）细胞的MIC 26和MIC 27水平分别降低和增加了一半。因此，我们想研究这种有趣的相互调节之间的MICOS载脂蛋白和FASTKD 2，MRG相关蛋白的意义。我们将确定导致这种相互管制的可能机制。此外，我们将使用STED超分辨率纳米显微镜在IM处破译MIC 26、MIC 27和FASTKD 2的纳米级组织，并使用FRAP技术在FASTKD 2科斯、MIC 26和MIC 27 D科斯中破译所述蛋白质的迁移率。最后但并非最不重要的是，我们将确定一方面存在于CJ的MIC 26、MIC 27与另一方面与MRG相关的FASTKD 2之间相互调节的功能意义。总之，我们将有助于理解一种新的机制，连接线粒体RNA生物学和IM重塑，这可以合理地解释与这些蛋白质相关的病理生理学。