The Acyl-CoA-binding domain-containing protein (ACBD3) plays multiple roles across the cell. Although generally associated with the Golgi apparatus, it operates also in mitochondria. In steroidogenic cells, ACBD3 is an important part of a multiprotein complex transporting cholesterol into mitochondria. Balance in mitochondrial cholesterol is essential for proper mitochondrial protein biosynthesis, among others. We generated ACBD3 knock-out (ACBD3-KO) HEK293 and HeLa cells and characterized the impact of protein absence on mitochondria, Golgi, and lipid profile. In ACBD3-KO cells, cholesterol level and mitochondrial structure and functions are not altered, demonstrating that an alternative pathway of cholesterol transport into mitochondria exists. However, ACBD3-KO cells exhibit enlarged Golgi area with absence of stacks and ribbon-like formation, confirming the importance of ACBD3 in Golgi stacking. The glycosylation of the LAMP2 glycoprotein was not affected by the altered Golgi structure. Moreover, decreased sphingomyelins together with normal ceramides and sphingomyelin synthase activity reveal the importance of ACBD3 in ceramide transport from ER to Golgi.

• Klíčová slova
• ACBD3, Golgi, OXPHOS, cholesterol, knock-out, mitochondria,
• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• biologický transport fyziologie   MeSH
• ceramidy metabolismus   MeSH
• cholesterol metabolismus   MeSH
• glykosylace MeSH
• Golgiho aparát metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• lidé MeSH
• membránové proteiny metabolismus   MeSH
• membránový protein 2 asociovaný s lyzozomy metabolismus   MeSH
• mitochondrie metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• transferasy pro jiné substituované fosfátové skupiny metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ACBD3 protein, human MeSH Prohlížeč
• adaptorové proteiny signální transdukční MeSH
• ceramidy MeSH
• cholesterol MeSH
• membránové proteiny MeSH
• membránový protein 2 asociovaný s lyzozomy MeSH
• phosphatidylcholine-ceramide phosphocholine transferase MeSH Prohlížeč
• transferasy pro jiné substituované fosfátové skupiny MeSH

At the end of the mammalian intra-uterine foetal development, a rapid switch from glycolytic to oxidative metabolism must proceed. Using microarray techniques, qPCR, enzyme activities and coenzyme Q content measurements, we describe perinatal mitochondrial metabolism acceleration in rat liver and skeletal muscle during the perinatal period and correlate the results with those in humans. Out of 1546 mitochondrial genes, we found significant changes in expression in 1119 and 827 genes in rat liver and skeletal muscle, respectively. The most remarkable expression shift occurred in the rat liver at least two days before birth. Coenzyme Q-based evaluation in both the rat model and human tissues showed the same trend: the total CoQ content is low prenatally, significantly increasing after birth in both the liver and skeletal muscle. We propose that an important regulator of rat coenzyme Q biosynthesis might be COQ8A, an atypical kinase involved in the biosynthesis of coenzyme Q. Our microarray data, a total of 16,557 RefSeq (Entrez) genes, have been deposited in NCBI's Gene Expression Omnibus and are freely available to the broad scientific community. Our microarray data could serve as a suitable background for finding key factors regulating mitochondrial metabolism and the preparation of the foetus for the transition to extra-uterine conditions.

• Klíčová slova
• coenzyme Q, human, microarray, mitochondria, prenatal, qPCR, rat, ubiquinone,
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Mitochondrial disorders (MD) may manifest in neonates, but early diagnosis is difficult. In this study, clinical and laboratory data were analyzed in 129 patients with neonatal onset of MD to identify any association between specific mitochondrial diseases and their symptoms with the aim of optimizing diagnosis. MATERIALS AND METHODS: Retrospective clinical and laboratory data were evaluated in 461 patients (331 families) with confirmed MD. RESULTS: The neonatal onset of MD was reported in 28% of the patients. Prematurity, intrauterine growth retardation and hypotonia necessitating ventilatory support were present in one-third, cardiomyopathy in 40%, neonatal seizures in 16%, Leigh syndrome in 15%, and elevated lactate level in 87%. Hyperammonemia was observed in 22 out of 52 neonates. Complex I deficiency was identified in 15, complex III in one, complex IV in 23, complex V in 31, combined deficiency of several complexes in 53, and PDH complex deficiency was identified in six patients. Molecular diagnosis was confirmed in 49 cases, including a newborn with a 9134A>G mutation in the MTATP6 gene, which has not been described previously. CONCLUSION: The most significant finding is the high incidence of neonatal cardiomyopathy and hyperammonemia. Based on our experience, we propose a diagnostic flowchart applicable to critically ill neonates suspicious for MD. This tool will allow for the use of direct molecular genetic analyses without the need for muscle biopsies in neonates with Alpers, Barth, MILS and Pearson syndromes, SCO1, SCO2, TMEM70, ATP5E, SUCLG1 gene mutations and PDH complex deficiency.

• MeSH
• hyperamonemie diagnóza   genetika   MeSH
• kardiomyopatie diagnóza   genetika   MeSH
• Leighova nemoc krev   diagnóza   genetika   MeSH
• lidé MeSH
• mitochondriální nemoci krev   diagnóza   genetika   MeSH
• mutace MeSH
• novorozenec nedonošený MeSH
• novorozenec MeSH
• retrospektivní studie MeSH
• růstová retardace plodu krev   diagnóza   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mitochondrial ATPases associated with diverse cellular activities (AAA) proteases are involved in the quality control and processing of inner-membrane proteins. Here we investigate the cellular activities of YME1L, the human orthologue of the Yme1 subunit of the yeast i-AAA complex, using stable short hairpin RNA knockdown and expression experiments. Human YME1L is shown to be an integral membrane protein that exposes its carboxy-terminus to the intermembrane space and exists in several complexes of 600-1100 kDa. The stable knockdown of YME1L in human embryonic kidney 293 cells led to impaired cell proliferation and apoptotic resistance, altered cristae morphology, diminished rotenone-sensitive respiration, and increased susceptibility to mitochondrial membrane protein carbonylation. Depletion of YME1L led to excessive accumulation of nonassembled respiratory chain subunits (Ndufb6, ND1, and Cox4) in the inner membrane. This was due to a lack of YME1L proteolytic activity, since the excessive accumulation of subunits was reversed by overexpression of wild-type YME1L but not a proteolytically inactive YME1L variant. Similarly, the expression of wild-type YME1L restored the lamellar cristae morphology of YME1L-deficient mitochondria. Our results demonstrate the importance of mitochondrial inner-membrane proteostasis to both mitochondrial and cellular function and integrity and reveal a novel role for YME1L in the proteolytic regulation of respiratory chain biogenesis.

• MeSH
• apoptóza MeSH
• ATPázy spojené s různými buněčnými aktivitami MeSH
• genový knockdown MeSH
• GTP-fosfohydrolasy metabolismus   MeSH
• lidé MeSH
• metaloendopeptidasy metabolismus   MeSH
• mitochondriální membrány metabolismus   MeSH
• mitochondriální proteiny MeSH
• mitochondrie metabolismus   MeSH
• NADH, NADPH oxidoreduktasy metabolismus   MeSH
• proliferace buněk * MeSH
• proteasy závislé na ATP metabolismus   MeSH
• proteasy metabolismus   MeSH
• protein - isoformy metabolismus   MeSH
• respirační komplex I MeSH
• respirační komplex IV metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny metabolismus   MeSH
• Saccharomyces cerevisiae cytologie   metabolismus   MeSH
• transport elektronů * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ATPázy spojené s různými buněčnými aktivitami MeSH
• GTP-fosfohydrolasy MeSH
• metaloendopeptidasy MeSH
• mitochondriální proteiny MeSH
• NADH, NADPH oxidoreduktasy MeSH
• NDUFB6 protein, human MeSH Prohlížeč
• OPA1 protein, human MeSH Prohlížeč
• proteasy závislé na ATP MeSH
• proteasy MeSH
• protein - isoformy MeSH
• respirační komplex I MeSH
• respirační komplex IV MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• YME1 protein, S cerevisiae MeSH Prohlížeč
• YME1L1 protein, human MeSH Prohlížeč