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The inner mitochondrial membrane cristae biogenesis
Efimova, Iuliia ; Mráček, Tomáš (advisor) ; Petrů, Markéta (referee)
Invaginations of the inner mitochondrial membrane originate cristae - important structural and bioenergetic mitochondrial compartments. Long-term observations of mitochondrial ultrastructure uncovered cristae dynamics, but did not identify mechanisms of cristae formation and maintenance. This thesis summarizes results of latest research on molecular mechanisms of mitochondrial cristae biogenesis, which are conserved from fungi to mammals including human. The emphasis is put on major remodeling factors: F1Fo-ATP synthase dimers, MICOS complex, OPA1 protein and cardiolipin. Their defects lead to extensive changes on cristae level, as well as on mitochondrial, cellular and organismal levels. Various pathophysiological conditions and human mitochondrial diseases are related to these defects. More detailed research of cristae biogenesis is therefore of high significance, new findings could assist in the development of new treatments for mitochondrial disorders.
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Structural composition and functional properties of mitochondrial FoF1 ATP synthase on models of specific subunits deficiencies
Efimova, Iuliia ; Mráček, Tomáš (advisor) ; Kalous, Martin (referee)
Mitochondrial ATP synthase represents the final complex of oxidative phosphorylation (OXPHOS) system located in the inner mitochondrial membrane. Its primary role is to utilize mitochondrial membrane potential (Δψm) generated by respiratory chain complexes to produce energy in the form of ATP. Mammalian ATP synthase comprises of 17 different subunits organized into membranous Fo and matrix-oriented F1 domains. Defects of complex V and their manifestation have been studied on mitochondrial, cellular, tissue and organism levels using different models, including human cell lines and cell lines derived from patient tissues. In many cases mitochondrial diseases display threshold behaviour, when genetic defect is phenotypically manifested only bellow certain threshold in particular enzyme complex activity and/or content. This work was aimed at elucidation of functional consequences of ATP synthase deficiency in HEK293 cell lines with suppressed gene expression of γ, δ or ε subunits of ATP synthase central stalk. We have analysed range of clones with respective subunits knockdown and found varying decrease in assembled ATP synthase content, which was mirrored by the decrease in individual ATP synthase subunits. The only exception was subunit Fo-c, whose levels remained unchanged or even increased. ATP...
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The inner mitochondrial membrane cristae biogenesis
Efimova, Iuliia ; Mráček, Tomáš (advisor) ; Petrů, Markéta (referee)
Invaginations of the inner mitochondrial membrane originate cristae - important structural and bioenergetic mitochondrial compartments. Long-term observations of mitochondrial ultrastructure uncovered cristae dynamics, but did not identify mechanisms of cristae formation and maintenance. This thesis summarizes results of latest research on molecular mechanisms of mitochondrial cristae biogenesis, which are conserved from fungi to mammals including human. The emphasis is put on major remodeling factors: F1Fo-ATP synthase dimers, MICOS complex, OPA1 protein and cardiolipin. Their defects lead to extensive changes on cristae level, as well as on mitochondrial, cellular and organismal levels. Various pathophysiological conditions and human mitochondrial diseases are related to these defects. More detailed research of cristae biogenesis is therefore of high significance, new findings could assist in the development of new treatments for mitochondrial disorders.
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