H2020Индивидуална стипендия2021–2023

CRIMIPRIM · The relationship between cristae shape and mitochondrial protein import in mitochondrial disease models

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-02-01 → 2023-01-31
Финансиране от ЕС: 171 473 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Връзката между формата на митохондриалните гънки и начина, по който протеините влизат в тях, се анализира чрез промени в протеина OPA1. Това помага да се разбере как структурните дефекти в митохондриите водят до заболявания, често срещани в европейското население.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

The relationship between cristae shape and mitochondrial protein import in mitochondrial disease models

The main aim of the project was to find a link between the mitochondrial protein import machinery and the cristae architecture regulated by the GTPase, OPA1. This is important because regulation of cristae architecture impacts the function of mitochondrial respiratory complexes and their assembly into supercomplexes, which in turn control the mitochondrial membrane potential and the generation of ATP. Both, membrane potential and ATP, are essential for mitochondrial biogenesis, i.e. the import of protein into the mitochondrion. The importance of mitochondria is testified by the set of diseases related to their altered function. Furthermore, abnormalities in the function of respiratory chain complexes or their assembly into supercomplexes causes a heterogeneous group of diseases with particularly high incidence in the European population. I used MEF KO for OPA1, with or without re-expression of the WT OPA1 protein, as well as one cell line expressing an OPA1 version (tetraCys OPA1) that cannot be proteolytically processed (only the long form (L-OPA1) of the protein is present). In line with the expected outcome of the project’s milestones, morphometric analysis of mitochondria in TetraCys OPA1 and OPA1 KO cells showed reduced juxtaposition between the outer (OM) and inner (IM) membrane of mitochondria. These ultrastructural changes were paralleled by defects in MICOS, MIB and the TIM23 import complex. This import pathway accounts for the import of most matrix proteins and is essential for mitochondrial biogenesis and respiration. Indeed, growth and respiration of cells lacking processed OPA1 were impaired. Our data indicate a role for OPA1 processing in the stability of the mitochondrial protein import complex TIM23, linking the core mitochondrial dynamics machinery to mitochondrial biogenesis. The latter is important because it opens the possibility for therapeutic targets, but also for understanding the dynamic response of mitochondria. In this fashion, tools to monitor the changes in the distance between the OM and the IM are being developed by us, to correlate those changes with the cellular response to different metabolic states and redox conditions, such changes are similar to the ones the cells face under several disease conditions, like mitochondrial diseases.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

The majority of mitochondrial proteins are imported from the cytosol into the organelle. The main mitochondrial protein import pathways account for the import of mitochondrial matrix and mitochondrial inner membrane (IM) proteins, e.g. the subunits of the respiratory chain complexes (RCC). This import process is facilitated by mitochondrial IM and outer membrane (OM) contact sites. Furthermore, the aforementioned pathways depend on the IM elechtrochemical gradient and ATP to take place. The host lab showed that mild overexpression of the dynamin-related protein optic atrophy 1 (OPA1) protects against IM proton electrochemical gradient lost upon complex III inhibition. OPA1 is involved in RCC stabilisation and cristae remodeling, but also in mitochondrial IM and outer membrane contacts. Recently, lower levels of mitochondrial import receptor and channels proteins were linked to Parkinson disease. The hypothesis of this proposal is that OPA1 directly influences TIM23 and TIM22 protein import pathways. This fellowship will follow three main aims; a) define the relationship between OPA1 and protein import in models of Leigh syndrome, b) determine cristae integrity in TOM20, TIM23 and TIM22 deficient cells and c) define protein import machinery molecular partners of OPA1. I will use classical biochemistry and BN-PAGE gels to determine the integrity of TIM23 and TIM22 and to assess the mitochondrial import capacity in the mouse models. Next, I will measure by electron microscopy the shape of the cristae and perform detailed morphometric analyses to determine if the protein import plays a role in cristae biogenesis. Finally, using complexomic analysis, I will aim to identify potential import pathway partners of Opa1 and establish their role by their deletion by CrispR/Cas9 in Opa1tg cells. This research will open the possibility to target the import machinery to remodel cristae in mitochondria in an OPA1-dependant manner as an alternative to treat mitochondrial disorders.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITA DEGLI STUDI DI PADOVA · PadovaКоординаторИталия