Disorders of ATP synthase, the key enzyme of mitochondrial energy provision belong to the most severe metabolic diseases presenting mostly as early-onset mitochondrial encephalo-cardio-myopathies. Mutations in four nuclear genes can result in isolated deficiency of ATP synthase, all sharing a similar biochemical phenotype - pronounced decrease in the content of fully assembled and functional ATP synthase complex. The thesis summarises studies on two distinct causes of ATP synthase deficiency. First is TMEM70 protein, a novel ancillary factor of ATP synthase, which represents most frequent determinant of severe inborn deficiency of ATP synthase. TMEM70 is a 21 kDa protein of the inner mitochondrial membrane, facilitating the biogenesis of mitochondrial ATP synthase, possibly through TMEM70 protein region exposed to the mitochondrial matrix, but the proper regulatory mechanism remains to be elucidated. In TMEM70-lacking patient fibroblasts the low content of ATP synthase induces compensatory adaptive upregulation of mitochondrial respiratory chain complexes III and IV, interestingly by a posttranscriptional mechanisms. The second type of ATP synthase deficiency studied was mtDNA m.9205delTA mutation affecting maturation of MT-ATP8/MT-ATP6/MT-CO3 mRNA and thus biosynthesis of Atp6 (subunit a) and Cox3...

Disorders of ATP synthase, the key enzyme of mitochondrial energy provision belong to the most severe metabolic diseases presenting mostly as early-onset mitochondrial encephalo-cardio-myopathies. Mutations in four nuclear genes can result in isolated deficiency of ATP synthase, all sharing a similar biochemical phenotype - pronounced decrease in the content of fully assembled and functional ATP synthase complex. The thesis summarises studies on two distinct causes of ATP synthase deficiency. First is TMEM70 protein, a novel ancillary factor of ATP synthase, which represents most frequent determinant of severe inborn deficiency of ATP synthase. TMEM70 is a 21 kDa protein of the inner mitochondrial membrane, facilitating the biogenesis of mitochondrial ATP synthase, possibly through TMEM70 protein region exposed to the mitochondrial matrix, but the proper regulatory mechanism remains to be elucidated. In TMEM70-lacking patient fibroblasts the low content of ATP synthase induces compensatory adaptive upregulation of mitochondrial respiratory chain complexes III and IV, interestingly by a posttranscriptional mechanisms. The second type of ATP synthase deficiency studied was mtDNA m.9205delTA mutation affecting maturation of MT-ATP8/MT-ATP6/MT-CO3 mRNA and thus biosynthesis of Atp6 (subunit a) and Cox3...

Rare diseases represent a clinically and genetically heterogeneous group of diseases affecting various organs and presenting at different ages. Identification and functional characterization of genetic defects causing individual rare diseases represent unique opportunity to understand biological functions of human genes and gene products as well as to basic pathogenetic mechanisms of individual diseases. This knowledge is prerequisite for their effective diagnosis, specific treatment and prevention and it also opens up an avenue for better understanding of complex diseases. My thesis documents basic conceptual and methodological developments of biochemical genetics, functional cloning, genetic mapping, positional cloning, DNA microarrays and genomic sequencing, which have provided a universal framework for effective characterization of the genetic architecture of almost all human diseases. This conceptual and technological developments are demonstrated on several cases of rare genetic diseases - adenylosuccinate lyase deficiency, mucopolysacharidosis type IIIC, Rotor syndrome, deficiency of ATP synthase, neuronal ceroid lipofuscinosis, GAPO syndrome and X -linked restrictive cardiomyopathy, which genetic and molecular basis I have helped to elucidate.

The study of rare genetic diseases presents unique opportunity to uncover the genetic and molecular basis of human traits and greatly helped to the identification of genes, to the elucidation of their function and to the characterization of metabolic pathways and cellular processes. Over the past decades, linkage analysis has been appropriate approach to search for the genes causing Mendelian diseases and contributed to the identification of many genes, but the genetic cause of many diseases remains unknown. New methods of studying the human genome, microarray technology and massively parallel sequencing (next generation sequencing), represent a way to efficiently identify the cause of genetically determined diseases, based on direct observation of mutations in the genome of affected individuals. These techniques replaced the traditional method of disease gene identification represented by linkage analysis and sequencing of candidate genes and have become the standard approach to elucidate the molecular basis of diseases. In this work, i describe the the results achieved by using these methods - identification of the genes underlying mucopolysacharidosis type IIIC, isolated defect of ATP synthase, Rotor syndrome, autosomal dominat ANCL and GAPO syndrome.

The study of rare genetic diseases presents unique opportunity to uncover the genetic and molecular basis of human traits and greatly helped to the identification of genes, to the elucidation of their function and to the characterization of metabolic pathways and cellular processes. Over the past decades, linkage analysis has been appropriate approach to search for the genes causing Mendelian diseases and contributed to the identification of many genes, but the genetic cause of many diseases remains unknown. New methods of studying the human genome, microarray technology and massively parallel sequencing (next generation sequencing), represent a way to efficiently identify the cause of genetically determined diseases, based on direct observation of mutations in the genome of affected individuals. These techniques replaced the traditional method of disease gene identification represented by linkage analysis and sequencing of candidate genes and have become the standard approach to elucidate the molecular basis of diseases. In this work, i describe the the results achieved by using these methods - identification of the genes underlying mucopolysacharidosis type IIIC, isolated defect of ATP synthase, Rotor syndrome, autosomal dominat ANCL and GAPO syndrome.