Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Despite HAART, a significant number of HIV-1-infected patients develop neurological complications. However, the presence of specific neurotropic HIV-1 strains, the extent of viral replication in the brain, and the type of cells infected remain controversial issues. To address this controversy we have analyzed different V3 loop sequences of viral isolates from four vertically HIV-1-infected children who developed HIV-1-related encephalopathy. Moreover, we have determined that some biological and molecular properties of HIV-1 might contribute to AIDS neurological dysfunctions. We detected very different HIV-1 isolates (X4 and R5) in the brain despite no great differences in clinical, pathological, or immunological parameters. In vitro, no differences in replicative competence in glial or neuroblastoma cells were observed between virus isolated from the blood of children with or without clinical neurological symptoms. The expression of both CXCR4 and CCR5 RNAs was observed in the brain independently of HIV-1 infection and viral strain predominant in this location. Our results failed to show a particular phenotypic property of the HIV-1 virus that might explain its neurovirulence and/or neurotropism.
J Mol Neurosci 2006
PMID:Lack of association of HIV-1 biological or molecular properties with neurotropism for brain cells. 1695 3

Glucose transporter type 1 deficiency syndrome (Glut1DS) is the result of autosomal-dominant loss-of-function mutation of the glucose transporter type 1 gene (GLUT1) leading to brain energy failure and epileptic encephalopathy. In this study, the protein products of the Glut1DS-associated GLUT1 missense mutations, S66F, R126C, and T295M, were characterized using the Glut1-green fluorescent protein (GFP) fusion expressed in CHO cells. Glut1-GFP expression was confirmed by Western blot and confocal microscopy. The applicability of this Glut1-GFP expression model in reporting Glut1 functional deficits was validated by re-confirming the glucose transport defects of the previously reported pathogenic mutations R126H, R126L, and R333W. While S66F, R126C, and T295M mutants were expressed and targeted to the cell membrane, these Glut1 mutants have significantly diminished membrane association and glucose transport activity (p<0.05) relative to the wild-type Glut1 protein. Consistent with the reduced Glut1 membrane association, glucose transport kinetics studies showed that S66F, R126C, and T295M mutants have significantly reduced (p<0.05) Vmax but not Km. Thus, Glut1 single amino acid substitute mutants S66F, R126C, and T295M impair glucose transport function and constitute Glut1-deficiency states in vitro. These results support the pathogenicity of Glut1 S66F, R126C, and T295M in vivo.
Mol Genet Metab 2007 Feb
PMID:Disease-associated Glut1 single amino acid substitute mutations S66F, R126C, and T295M constitute Glut1-deficiency states in vitro. 1705 34

1. Patients affected by isovaleric acidemia (IVAcidemia) suffer from acute episodes of encephalopathy. However, the mechanisms underlying the neuropathology of this disease are poorly known. The objective of the present study was to investigate the in vitro effects of the metabolites that predominantly accumulate in IVAcidemia, namely isovaleric acid (IVA), 3-hydroxyisovaleric acid (3-OHIVA) and isovalerylglycine (IVG), on important parameters of energy metabolism, such as (14)CO(2) production from acetate and the activities of the respiratory chain complexes I-IV, creatine kinase and Na(+), K(+)-ATPase in synaptic plasma membranes from cerebral cortex homogenates of 30-day-old rats. 2. We observed that 3-OHIVA acid and IVG did not affect all the parameters analyzed. Similarly, (14)CO(2) production from acetate (Krebs cycle activity), the activities of creatine kinase, and of the respiratory chain complexes was not modified by IVA. In contrast, IVA exposition to cortical homogenates provoked a marked inhibition of Na(+), K(+)-ATPase activity. However, this activity was not changed when IVA was directly exposed to purified synaptic plasma membranes, suggesting an indirect effect of this organic acid on the enzyme. Furthermore, pretreatment of cortical homogenates with alpha-tocopherol and creatine totally prevented IVA-induced inhibition on Na(+), K(+)-ATPase activity from synaptic plasma membranes, whereas glutathione (GSH) and the NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) did not alter this inhibition. 3. These data indicate that peroxide radicals were probably involved in this inhibitory effect. Since Na(+), K(+)-ATPase is a critical enzyme for normal brain development and functioning and necessary to maintain neuronal excitability, it is presumed that the inhibitory effect of IVA on this activity may be involved in the pathophysiology of the neurological dysfunction of isovaleric acidemic patients.
Cell Mol Neurobiol 2007 Jun
PMID:Isovaleric acid reduces Na+, K+-ATPase activity in synaptic membranes from cerebral cortex of young rats. 1739 58

We investigated two unrelated children with an isolated defect of mitochondrial complex III activity. The clinical picture was characterized by a progressive encephalopathy featuring early-onset developmental delay, spasticity, seizures, lactic acidosis, brain atrophy and MRI signal changes in the basal ganglia. Both children were compound heterozygotes for novel mutations in the human bc1 synthesis like (BCS1L) gene, which encodes an AAA mitochondrial protein putatively involved in both iron homeostasis and complex III assembly. The pathogenic role of the mutations was confirmed by complementation assays, using a DeltaBcs1 strain of Saccharomyces cerevisiae. By investigating complex III assembly and the structural features of the BCS1L gene product in skeletal muscle, cultured fibroblasts and lymphoblastoid cell lines from our patients, we have demonstrated, for the first time in a mammalian system, that a major function of BCS1L is to promote the maturation of complex III and, more specifically, the incorporation of the Rieske iron-sulfur protein into the nascent complex. Defective BCS1L leads to the formation of a catalytically inactive, structurally unstable complex III. We have also shown that BCS1L is contained within a high-molecular-weight supramolecular complex which is clearly distinct from complex III intermediates.
Hum Mol Genet 2007 May 15
PMID:Impaired complex III assembly associated with BCS1L gene mutations in isolated mitochondrial encephalopathy. 1740 14

We report a recessive mutation in the tyrosine hydroxylase gene (TH) promoter (c.1-71C>T), present at homozygosity in a patient with dopa-responsive encephalopathy. The change lies in a cAMP response element (CRE) and alters a binding site for the CREM transcription factor. Previous studies support that the CRE in the TH gene is essential for its transcription, suggesting that mutations within this consensus motif may cause an impairment of catecholamine biosynthesis and lead to a pathogenic phenotype.
Mol Genet Metab 2007 Nov
PMID:A homozygous tyrosine hydroxylase gene promoter mutation in a patient with dopa-responsive encephalopathy: clinical, biochemical and genetic analysis. 1769 83

In two patients who presented at late infancy with hypotonia, nystagmus and ataxia, interspersed with acute episodes of encephalopathy, we identified a mutation in a complex I assembly factor, NDUFA12L, which resulted in a marked reduction of the NDUFA12L protein and of complex I activity. The involvement of the mamillothalamic tracts, substantia nigra/medial lemniscus, medial longitudinal fasciculus, the corpus medullare and the cerebellum, with relative sparing of the cortex and subcortical white matter was distinctive and resembled the findings in the first and only known patient with mutation in the NDUFA12L gene.
Mol Genet Metab 2008 May
PMID:The unique neuroradiology of complex I deficiency due to NDUFA12L defect. 1818 Jan 88

In this study, we report the X-ray crystal structure of an N-terminally truncated variant of the bacterial serpin, tengpin (tengpinDelta42). Our data reveal that tengpinDelta42 adopts a variation of the latent conformation in which the reactive center loop is hyperinserted into the A beta-sheet and removed from the vicinity of the C-sheet. This conformational change leaves the C beta-sheet completely exposed and permits antiparallel edge-strand interactions between the exposed portion of the reactive center loop of one molecule and strand s2C of the C beta-sheet of the neighboring molecule in the crystal lattice. Our structural data thus reveal that tengpinDelta42 forms a loop C-sheet polymer in the crystal lattice. In vivo serpins have a propensity to misfold and form long-chain polymers, a process that underlies serpinopathies such as emphysema, thrombosis and dementia. Native serpins are thought to polymerize via a loop A-sheet mechanism. However, studies on plasminogen activator inhibitor 1 and the S49P variant of human neuroserpin reveal that the latent form of these molecules can also polymerize. Polymerization of latent neuroserpin may be important for the development of familial encephalopathy with neuroserpin inclusion bodies. Our structural data provide a possible mechanism for polymerization by latent serpins.
J Mol Biol 2008 Mar 07
PMID:A structural basis for loop C-sheet polymerization in serpins. 1823 18

Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is an autosomal dominant dementia that is characterized by the retention of polymers of neuroserpin as inclusions within the endoplasmic reticulum (ER) of neurons. We have developed monoclonal antibodies that detect polymerized neuroserpin and have used COS-7 cells, stably transfected PC12 cell lines and transgenic Drosophila melanogaster to characterize the cellular handling of all four mutant forms of neuroserpin that cause FENIB. We show a direct correlation between the severity of the disease-causing mutation and the accumulation of neuroserpin polymers in cell and fly models of the disease. Moreover, mutant neuroserpin causes locomotor deficits in the fly allowing us to demonstrate a direct link between polymer accumulation and neuronal toxicity.
Hum Mol Genet 2008 Jun 01
PMID:The intracellular accumulation of polymeric neuroserpin explains the severity of the dementia FENIB. 1826 59

Patients with an influenza virus infection can be complicated by acute encephalopathy and encephalitis. To investigate the immune reactions involved in the neurocomplication, mouse microglia and astrocytes were isolated, infected with human H1N1 and avian H5N1 influenza viruses, and examined for their immune responses. We observed homogeneously distributed viral receptors, sialic acid (SA)-alpha2,3-Galactose (Gal) and SA-alpha2,6-Gal, on microglia and astrocytes. Both viruses were replicative and productive in microglia and astrocytes. Virus-induced apoptosis and cytopathy in infected cells were observed at 24 h post-infection (p.i.). Expression of IL-1beta, IL-6 and TNF-alpha mRNA examined at 6 h and 24 h p.i. was up-regulated, and their expression levels were considerably higher in H5N1 infection. The amounts of secreted proinflammatory IL-1beta, IL-6 and TNF-alpha at 6 h and 24 h p.i. were also induced, with greater induction by H5N1 infection. This study is the first demonstration that both human H1N1 and avian H5N1 influenza viruses can infect mouse microglia and astrocytes and induce apoptosis, cytopathy, and proinflammatory cytokine production in them in vitro. Our results suggest that the direct cellular damage and the consequences of immunopathological injury in the CNS contribute to the influenza viral pathogenesis.
Cell Mol Immunol 2008 Apr
PMID:Apoptosis and proinflammatory cytokine responses of primary mouse microglia and astrocytes induced by human H1N1 and avian H5N1 influenza viruses. 1844 41

Adenylosuccinate lyase (ADSL) catalyzes two steps in purine nucleotide metabolism-the 8th step in the de novo pathway: conversion of succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazole carboxamide ribotide (AICAR), and conversion of adenylosuccinate (S-AMP) to adenylate (AMP) in the purine nucleotide cycle. To date, over 50 patients have been reported suffering from ADSL deficiency. We report all seven so far diagnosed Polish patients with this defect. Most of our patients shared intractable seizures and psychomotor retardation since the neonatal period and had biochemical evidence of severe (type I) deficiency. Two patients with type II suffered only from mild/moderate psychomotor retardation and showed a transientvisual contact disturbance. One patient had a fatal neonatal form of ADSL deficiency with lack of spontaneous movement, respiratory failure, severe encephalopathy and intractable seizures. Analysis of the ADSL gene showed that four apparently unrelated patients carried a R426H mutation (two homozygous and two compound heterozygous). With the exception of the latter mutation, a Y114H mutation that had been reported previously, and a novel mutation T242I, all other mutations (including D268H and three novel S23R, D215H and I351T mutations) were found only in single families in single alleles. A search for this disorder should be included in the screening program of all infants with unexplained neonatal seizures, severe infantile epileptic encephalopathy, developmental delay, hypotonia, and/or autistic features.
Mol Genet Metab 2008 Aug
PMID:Clinical, biochemical and molecular findings in seven Polish patients with adenylosuccinate lyase deficiency. 1852 58


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>