OBJECTIVE: Glycine encephalopathy, also known as nonketotic hyperglycinemia (NKH), is an inherited neurometabolic disorder with variable clinical course and severity, ranging from infantile epileptic encephalopathy to psychiatric disorders. A precise phenotypic characterization and an evaluation of predictive approaches are needed. METHODS: Longitudinal clinical and biochemical data of 25 individuals with NKH from the patient registry of the International Working Group on Neurotransmitter Related Disorders were studied with in silico analyses, pathogenicity scores, and molecular modeling of GLDC and AMT variants. RESULTS: Symptom onset (p < 0.01) and diagnosis occur earlier in life in severe NKH (p < 0.01). Presenting symptoms affect the age at diagnosis. Psychiatric problems occur predominantly in attenuated NKH. Onset age ≥ 3 months (66% specificity, 100% sensitivity, area under the curve [AUC] = 0.87) and cerebrospinal fluid (CSF)/plasma glycine ratio ≤ 0.09 (57% specificity, 100% sensitivity, AUC = 0.88) are sensitive indicators for attenuated NKH, whereas CSF glycine concentration ≥ 116.5μmol/l (100% specificity, 93% sensitivity, AUC = 0.97) and CSF/plasma glycine ratio ≥ 0.15 (100% specificity, 64% sensitivity, AUC = 0.88) are specific for severe forms. A ratio threshold of 0.128 discriminates the overlapping range. We present 10 new GLDC variants. Two mild variants resulted in attenuated, whereas 2 severe variants or 1 mild and 1 severe variant led to severe phenotype. Based on clinical, biochemical, and genetic parameters, we propose a severity prediction model. INTERPRETATION: This study widens the phenotypic spectrum of attenuated NKH and expands the number of pathogenic variants. The multiparametric approach provides a promising tool to predict disease severity, helping to improve clinical management strategies. ANN NEUROL 2022;92:292-303.

• MeSH
• fenotyp MeSH
• glycin mozkomíšní mok   genetika   MeSH
• lidé MeSH
• mutace MeSH
• neketotická hyperglycinemie * diagnóza   genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Linker for activation in T cells (LAT) is a critical regulator of T-cell development and function. It organises signalling events at the plasma membrane. However, the mechanism, which controls LAT localisation at the plasma membrane, is not fully understood. Here, we studied the impact of helix-breaking amino acids, two prolines and one glycine, in the transmembrane segment on localisation and function of LAT. Using in silico analysis, confocal and super-resolution imaging and flow cytometry, we demonstrate that central proline residue destabilises transmembrane helix by inducing a kink. The helical structure and dynamics are further regulated by glycine and another proline residue in the luminal part of LAT transmembrane domain. Replacement of these residues with aliphatic amino acids reduces LAT dependence on palmitoylation for sorting to the plasma membrane. However, surface expression of these mutants is not sufficient to recover function of nonpalmitoylated LAT in stimulated T cells. These data indicate that geometry and dynamics of LAT transmembrane segment regulate its localisation and function in immune cells.

• MeSH
• adaptorové proteiny signální transdukční chemie   genetika   metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• glycin genetika   metabolismus   MeSH
• interferenční mikroskopie MeSH
• Jurkat buňky MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• membránové proteiny chemie   genetika   metabolismus   MeSH
• mutace MeSH
• prolin genetika   metabolismus   MeSH
• proteinové domény MeSH
• sekundární struktura proteinů MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• simulace molekulární dynamiky MeSH
• T-lymfocyty metabolismus   MeSH
• vápník metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND AND AIM: Osteogenesis imperfecta (OI), also called brittle bone disease, is a clinically and genetically heterogeneous disorder characterized by decreased bone density. Autosomal dominant forms result from mutations in either the COL1A1 (collagen type I alpha-1 chain) or COL1A2 (collagen type I alpha-2 chain) genes encoding the type I collagen. The aim of this study was to identify mutations and allelic variants of the COL1A1 gene in patients with osteogenesis imperfecta (OI). METHODS AND RESULTS: Molecular genetic analysis of the COL1A1 gene was performed in a cohort of 34 patients with OI. The DNA samples were analysed by PCR and Sanger sequencing. DNA changes in coding sequences of the gene were compared with Type 1 Collagen Mutation Database. Genetic variants resulting in either quantitatively or structurally defective protein production were found in 6 unrelated patients. Four identified mutations are connected to decreased protein production (Tyr47X, Arg131X, Arg415X, Gln1341X), 2 result in amino acid substitution (Cys61Phe, Pro1186Ala) and the last affects splicing (c.1057-1G>T). Further, one silent mutation (Gly794Gly) was detected. No protein analysis was performed. CONCLUSION: Of the 8 identified mutations, 5 were novel and have not been reported before. Only one causes substitution of glycine located within the Gly-X-Y triplets in the triple helical domain. Two mutations are located in major ligand binding regions (MLBR) which are important for bone strength and flexibility. Although the genotype-phenotype correlation is still unclear, our findings should contribute to elucidating this relationship in patients diagnosed with OI.

• MeSH
• dítě MeSH
• dospělí MeSH
• fenotyp MeSH
• genotyp MeSH
• glycin genetika   MeSH
• heterozygot MeSH
• kolagen typu I genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mutace genetika   MeSH
• osteogenesis imperfecta genetika   MeSH
• substituce aminokyselin genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The role of KRAS mutations in molecular targeted therapy by epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) has not been fully understood. The present investigation is aimed at an elucidation of the role of specific KRAS mutation types in predicting outcomes of patients with advanced NSCLC receiving EGFR-TKI therapy. Initially, 448 NSCLC patients were tested for the presence of KRAS mutations, to obtain frequencies of specific KRAS mutation types. Subsequently, the clinical outcome of treatment was evaluated in a subgroup of 38 KRAS-positive patients receiving EGFR-TKI therapy. KRAS mutations were detected in 69 of 448 patients (15.4%), mostly in smokers (17.86% vs. 5.8%, P = 0.0048), and appeared more frequently in adenocarcinomas than in squamous cell NSCLC or NSCLC that is not otherwise specified (21% vs. 6.99% vs. 4.4%, P = 0.0004). The most frequent type of KRAS mutation was G12C. The progression-free survival (PFS) was doubled in a group of non-G12C patients compared with that of the G12C group (9.0 wk vs. 4.3 wk, P = 0.009). The overall survival (OS) was not significantly different between non-G12C and G12C groups (12.1 wk vs. 9.3 wk, P = 0.068). The G12C KRAS mutation is a strong negative predictor for EGFR-TKI treatment, whereas other KRAS mutation types have not negatively predicted treatment efficacy compared with that for the wild-type KRAS genotype.

• MeSH
• antitumorózní látky terapeutické užití   MeSH
• biomarkery farmakologické metabolismus   MeSH
• chemorezistence genetika   MeSH
• cystein genetika   MeSH
• dospělí MeSH
• erbB receptory antagonisté a inhibitory   MeSH
• glycin genetika   MeSH
• inhibitory proteinkinas terapeutické užití   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• missense mutace fyziologie   MeSH
• nádorové biomarkery genetika   fyziologie   MeSH
• nádory plic diagnóza   farmakoterapie   genetika   MeSH
• nemalobuněčný karcinom plic diagnóza   farmakoterapie   genetika   MeSH
• prognóza MeSH
• protoonkogenní proteiny genetika   metabolismus   fyziologie   MeSH
• ras proteiny genetika   metabolismus   fyziologie   MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• substituce aminokyselin fyziologie   MeSH
• tyrosinkinasy antagonisté a inhibitory   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH

Mitochondrial processing peptidases are heterodimeric enzymes (alpha/betaMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an alpha/beta heterodimer. By contrast, and so far uniquely among eukaryotes, the Giardia processing peptidase functions as a monomer comprising a single betaMPP-like catalytic subunit. The structure and surface charge distribution of the Giardia processing peptidase predicted from a 3-D protein model appear to have co-evolved with the properties of Giardia mitosomal targeting sequences, which, unlike classic mitochondrial targeting signals, are typically short and impoverished in positively charged residues. The majority of hydrogenosomal presequences resemble those of mitosomes, but longer, positively charged mitochondrial-type presequences were also identified, consistent with the retention of the Trichomonas alphaMPP-like subunit. Our computational and experimental/functional analyses reveal that the divergent processing peptidases of Giardia mitosomes and Trichomonas hydrogenosomes evolved from the same ancestral heterodimeric alpha/betaMPP metallopeptidase as did the classic mitochondrial enzyme. The unique monomeric structure of the Giardia enzyme, and the co-evolving properties of the Giardia enzyme and substrate, provide a compelling example of the power of reductive evolution to shape parasite biology.

• MeSH
• down regulace genetika   MeSH
• fylogeneze MeSH
• genová dávka MeSH
• Giardia lamblia genetika   metabolismus   ultrastruktura   MeSH
• glycin fyziologie   genetika   chemie   MeSH
• metaloendopeptidasy genetika   chemie   metabolismus   MeSH
• mitochondrie metabolismus   MeSH
• multimerizace proteinu MeSH
• organely metabolismus   MeSH
• podjednotky proteinů genetika   MeSH
• posttranslační úpravy proteinů genetika   MeSH
• proteinové domény bohaté na prolin fyziologie   genetika   MeSH
• řízená evoluce molekul MeSH
• sekvence aminokyselin MeSH
• transport proteinů MeSH
• Trichomonas vaginalis genetika   metabolismus   ultrastruktura   MeSH
• vodík metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• srovnávací studie MeSH

OBJECTIVES: A 25-yr-old man from Prague had abnormal bleeding after several surgical operations with low fibrinogen level and hypofibrinogenemia was suspected. PATIENTS AND METHODS: The patient, 25 yr-old male had a low fibrinogen concentration as determined by the thrombin time and immunoturbidimetrical method. His 48-yr-old mother presented with normal coagulation tests, normal fibrinogen level and reported no history of bleeding. To identify the genetic mutation responsible for this hypofibrinogen, genomic DNA extracted from the blood was analyzed. Fibrin polymerization measurement, kinetics of fibrinopeptide release, fibrinogen clottability measurement, mass spectroscopy, and scanning electron microscopy were performed. RESULTS: DNA sequencing showed heterogeneous fibrinogen gammaG351S mutation in the propositus. The mutant chain was found not to be expressed to the circulation by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Scanning electron micrographs of the patient's fibrin clot as well as kinetics of fibrinopeptide release and fibrin polymerization were found to be normal. CONCLUSION: A case of hypofibrinogenemia gammaG351S was found by routine coagulation testing and was genetically identified.

• MeSH
• dospělí MeSH
• fibrinogen genetika   metabolismus   MeSH
• financování organizované MeSH
• glycin genetika   MeSH
• krev MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikroskopie elektronová rastrovací MeSH
• molekulární sekvence - údaje MeSH
• sekvence aminokyselin MeSH
• serin genetika   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH

• MeSH
• alanin genetika   MeSH
• bodová mutace MeSH
• finanční podpora výzkumu jako téma MeSH
• glycin genetika   MeSH
• Leberova atrofie zrakového nervu MeSH
• lidé MeSH
• longitudinální studie MeSH
• mitochondriální DNA genetika   MeSH
• mutační analýza DNA MeSH
• zdraví rodiny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• srovnávací studie MeSH

• MeSH
• fenotyp MeSH
• genetická terapie trendy   MeSH
• glycin genetika   MeSH
• inzerční mutageneze genetika   metody   MeSH
• letální geny MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• osteogenesis imperfecta genetika   patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• srovnávací studie MeSH

We have identified a novel CFTR missense mutation associated with a protein trafficking defect in mammalian cells but normal chloride channel properties in a Xenopus oocyte assay. The mutation, a cysteine for glycine substitution at residue 480 (G480C), was detected in a pancreatic insufficient, African-American, cystic fibrosis (CF) patient. G480C was found on one additional CF chromosome and on none of 220 normal chromosomes, including 160 chromosomes from normal African-American individuals. Western blot analysis and immunofluorescence studies revealed that, in 293T cells, the encoded mutant protein was not fully glycosylated and failed to reach the plasma membrane, suggesting that the G480C protein was subject to defective intracellular processing. However, in Xenopus oocytes, a system in which mutant CFTR proteins are less likely to experience an intracellular processing/trafficking deficit, expression of G480C CFTR was associated with a chloride conductance that exhibited a sensitivity to activation by forskolin and 3-isobutyl-1-methylxanthine (IBMX) that was similar to that of wild-type CFTR. This appears to be the first identification of a CFTR mutant with a single amino acid substitution in which the sole basis for disease is mislocalization of the protein.

• MeSH
• AMP cyklický farmakologie   metabolismus   MeSH
• bodová mutace * MeSH
• chloridové kanály fyziologie   genetika   MeSH
• cystein genetika   MeSH
• cystická fibróza * genetika   MeSH
• glycin genetika   MeSH
• imunoblotting MeSH
• kultivované buňky MeSH
• lidé MeSH
• membránové proteiny * analýza   fyziologie   genetika   MeSH
• molekulární sekvence - údaje MeSH
• oocyty fyziologie   účinky léků   MeSH
• proteinkinasy závislé na cyklickém AMP, podjednotka RIIbeta farmakologie   MeSH
• savci genetika   MeSH
• sekvence nukleotidů MeSH
• teplota MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH

• MeSH
• dítě MeSH
• glycin genetika   metabolismus   MeSH
• lidé MeSH
• nemoci centrálního nervového systému diagnóza   terapie   MeSH
• nemoci novorozenců diagnóza   terapie   MeSH
• novorozenec MeSH
• vrozené poruchy metabolismu diagnóza   terapie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• Publikační typ
• kazuistiky MeSH