About: DNAJC19 is a research topic. Over the lifetime, 20 publications have been published within this topic receiving 645 citations. The topic is also known as: PAM18 & TIM14.
TL;DR: The DNAJC19 protein was previously localised to the mitochondria in cardiac myocytes, and shares sequence and organisational similarity with proteins from several species including two yeast mitochondrial inner membrane proteins, Mdj2p and Tim14, suggesting that the unique phenotype of DCMA may be the result of defective mitochondrial protein import.
Abstract: Background: A novel autosomal recessive condition, dilated cardiomyopathy with ataxia (DCMA) syndrome, has been identified in the Canadian Dariusleut Hutterite population, characterised by early onset dilated cardiomyopathy with conduction defects, non-progressive cerebellar ataxia, testicular dysgenesis, growth failure, and 3-methylglutaconic aciduria. Objective: To map DCMA syndrome and identify the mutation underlying this condition. Methods: A genome wide scan was undertaken on consanguineous Hutterite families using a homozygosity mapping approach in order to identify the DCMA associated chromosomal region. Mutation analysis was carried out on positional candidate genes in this region by sequencing. Reverse transcriptase polymerase chain reaction and bioinformatics analyses were then used to characterise the mutation and determine its effect on the protein product. Results: The association of DCMA syndrome with a 2.2 Mb region of chromosome 3q26.33 was found. A disease associated mutation was identified: IVS3-1 G→C in the DNAJC19 gene, encoding a DNAJ domain containing protein of previously unknown function (Entrez Gene ID 131118). Conclusions: The DNAJC19 protein was previously localised to the mitochondria in cardiac myocytes, and shares sequence and organisational similarity with proteins from several species including two yeast mitochondrial inner membrane proteins, Mdj2p and Tim14. Tim14 is a component of the yeast inner mitochondrial membrane presequence translocase, suggesting that the unique phenotype of DCMA may be the result of defective mitochondrial protein import. It is only the second human disorder caused by defects in this pathway that has been identified.
TL;DR: The experiments suggest that PHB/DNAJC19 membrane domains regulate cardiolipin remodeling by tafazzin and explain similar clinical symptoms in two inherited cardiomyopathies by an impaired cardiolIPin metabolism in mitochondrial membranes.
TL;DR: This is the first clinical report of DCMA syndrome, a human DNAJC19 deficiency that is related to cases of severe dilated cardiomyopathy diagnosed in Europe and causes a relatively specific finding in urinary organic acid analysis (methylglutaconic aciduria type V).
Abstract: New mutation of mitochondrial DNAJC19 causing dilated and noncompaction cardiomyopathy, anemia, ataxia, and male genital anomalies
TL;DR: 3-methylglutaconic aciduria is found quite frequently in patients suspected of a metabolic disorder, and mitochondrial dysfunction is indeed a common denominator, and it is only a discriminative feature of patients with mutations in AUH, TAZ, SERAC1, OPA3, DNAJC19 and TMEM70.
Abstract: Elevated urinary excretion of 3-methylglutaconic acid is considered rare in patients suspected of a metabolic disorder. In 3-methylglutaconyl-CoA hydratase deficiency (mutations in AUH), it derives from leucine degradation. In all other disorders with 3-methylglutaconic aciduria the origin is unknown, yet mitochondrial dysfunction is thought to be the common denominator. We investigate the biochemical, clinical and genetic data of 388 patients referred to our centre under suspicion of a metabolic disorder showing 3-methylglutaconic aciduria in routine metabolic screening. Furthermore, we investigate 591 patients with 50 different, genetically proven, mitochondrial disorders for the presence of 3-methylglutaconic aciduria. Three percent of all urine samples of the patients referred showed 3-methylglutaconic aciduria, often in correlation with disorders not reported earlier in association with 3-methylglutaconic aciduria (e.g. organic acidurias, urea cycle disorders, haematological and neuromuscular disorders). In the patient cohort with genetically proven mitochondrial disorders 11% presented 3-methylglutaconic aciduria. It was more frequently seen in ATPase related disorders, with mitochondrial DNA depletion or deletion, but not in patients with single respiratory chain complex deficiencies. Besides, it was a consistent feature of patients with mutations in TAZ, SERAC1, OPA3, DNAJC19 and TMEM70 accounting for mitochondrial membrane related pathology. 3-methylglutaconic aciduria is found quite frequently in patients suspected of a metabolic disorder, and mitochondrial dysfunction is indeed a common denominator. It is only a discriminative feature of patients with mutations in AUH, TAZ, SERAC1, OPA3, DNAJC19 TMEM70. These conditions should therefore be referred to as inborn errors of metabolism with 3-methylglutaconic aciduria as discriminative feature.
TL;DR: It is concluded that QIL1/MIC13 deficiency in human, is associated with disassembly of the MICOS complex, with the associated aberration of cristae morphology and mitochondrial respiratory dysfunction.
Abstract: The mitochondrial inner membrane possesses distinct subdomains including cristae, which are lamellar structures invaginated into the mitochondrial matrix and contain the respiratory complexes. Generation of inner membrane domains requires the complex interplay between the respiratory complexes, mitochondrial lipids and the recently identified mitochondrial contact site and cristae organizing system (MICOS) complex. Proper organization of the mitochondrial inner membrane has recently been shown to be important for respiratory function in yeast. Here we aimed at a molecular diagnosis in a brother and sister from a consanguineous family who presented with a neurodegenerative disorder accompanied by hyperlactatemia, 3-methylglutaconic aciduria, disturbed hepatocellular function with abnormal cristae morphology in liver and cerebellar and vermis atrophy, which suggest mitochondrial dysfunction. Using homozygosity mapping and exome sequencing the patients were found to be homozygous for the p.(Gly15Glufs*75) variant in the QIL1/MIC13 (C19orf70) gene. QIL1/MIC13 is a constituent of MICOS, a six subunit complex that helps to form and/or stabilize cristae junctions and determine the placement, distribution and number of cristae within mitochondria. In patient fibroblasts both MICOS subunits QIL1/MIC13 and MIC10 were absent whereas MIC60 was present in a comparable abundance to that of the control. We conclude that QIL1/MIC13 deficiency in human, is associated with disassembly of the MICOS complex, with the associated aberration of cristae morphology and mitochondrial respiratory dysfunction. 3-Methylglutaconic aciduria is associated with variants in genes encoding mitochondrial inner membrane organizing determinants, including TAZ, DNAJC19, SERAC1 and QIL1/MIC13.