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

Congenital disorders of glycosylation (CDG) are caused by autosomal recessive mutations in genes affecting N-glycan biosynthesis. Mutations in the PMM2 gene, which encodes the enzyme phosphomannomutase (mannose 6-phosphate <--> mannose 1-phosphate), give rise to the most common form: CDG-Ia. These patients typically present with dysmorphic features and neurological abnormalities, cerebellar hypoplasia, ataxia, hypotonia, and coagulopathy, in addition to feeding problems. However, the clinical symptoms vary greatly. The great majority of known CDG-Ia patients are of European descent where the most common mutant alleles originated. This ethnic bias can also be explained by lack of global awareness of the disorder. Here we report an Asian patient with prominent systemic features that we diagnosed with CDG-Ia resulting from two new mutations in the PMM2 gene (310C --> G resulting in L104V and an intronic mutation IVS1-1G --> A). The latter mutation seems to result in lower mRNA levels, and the L104V has been functionally analyzed in a yeast expression system together with known mutations. The Filipino and Cambodian origins of the parents show that CDG-Ia mutations occur in these ethnic groups as well as in Caucasians.
Mol Genet Metab 2001 May
PMID:Functional analysis of novel mutations in a congenital disorder of glycosylation Ia patient with mixed Asian ancestry. 1135 Jan 85

The oxidative stress resulting from the neurogenic ataxia retinitis pigmentosa (NARP) mutation in the mitochondrial ATPase 6 gene was investigated in cultured skin fibroblasts from two patients presenting an isolated complex V deficiency. Taken as an index for superoxide overproduction, a huge induction of the superoxide dismutase (SOD) activity was observed in these fibroblasts harboring >90% of mutant mitochondrial DNA. The oxidative stress denoted by the high SOD activity was associated with increased cell death. In glucose-rich medium, apoptosis appeared as the main cell death process associated with complex V deficiency. Complex V-deficient fibroblasts, which showed a high SOD induction and stained positive for all studied apoptosis markers, were successfully rescued by perfluoro-tris-phenyl nitrone, an antioxidant spin-trap molecule. This established that the superoxide production associated with the ATPase deficiency triggered by the NARP mutation could be sufficient to override cell antioxidant defenses and to result in cell commitment to die. The potential participation of superoxides and/or their derivatives in the pathogenic mechanism of specific respiratory chain disorders makes them a promising target for therapy.
Hum Mol Genet 2001 May 15
PMID:Superoxide-induced massive apoptosis in cultured skin fibroblasts harboring the neurogenic ataxia retinitis pigmentosa (NARP) mutation in the ATPase-6 gene of the mitochondrial DNA. 1137 15

Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation.
Cell Mol Biol (Noisy-le-grand) 2001 May
PMID:Response of avian embryonic brain to spatially segmented x-ray microbeams. 1144 56

Genetic etiologies of at least 20% of autosomal dominant cerebellar ataxias (ADCAs) have yet to be clarified. We identified a novel spinocerebellar ataxia (SCA) form in four Japanese pedigrees which is caused by an abnormal CAG expansion in the TATA-binding protein (TBP) gene, a general transcription initiation factor. Consequently, it has been added to the group of polyglutamine diseases. This abnormal expansion of glutamine tracts in TBP bears 47--55 repeats, whereas the normal repeat number ranges from 29 to 42. Immunocytochemical examination of a postmortem brain which carried 48 CAG repeats detected neuronal intranuclear inclusion bodies that stained with anti-ubiquitin antibody, anti-TBP antibody and with the 1C2 antibody that recognizes specifically expanded pathological polyglutamine tracts. We therefore propose that this new disease be called SCA17 (TBP disease).
Hum Mol Genet 2001 Jul 01
PMID:SCA17, a novel autosomal dominant cerebellar ataxia caused by an expanded polyglutamine in TATA-binding protein. 1144 35

Diisopropyl phosphorofluoridate (DFP) is a type I organophosphorus compound and produces delayed neurotoxicity (OPIDN) in adult hens. A single dose of DFP (1.7 mg/kg, s.c.) produces mild ataxia in hens in 7-14 days, which develops into severe ataxia or paralysis as the disease progresses. We have previously shown altered expression of several proteins (e.g. Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) alpha-subunit, tau, tubulin, neurofilament protein (NF), vimentin, GFAP) and an immediate early gene (e.g. c-fos) in DFP-treated hens. Here we show an increase in protein kinase A (PKA) protein level and activity in the spinal cord at 1-day and 5-days time periods after DFP administration. We also determined the protein levels of protein kinase C (PKC), CaM kinase II and several phosphatases (i.e. phosphatase 1 (PP1), phosphatase 2A (PP2A), phosphatase 2B (PP2B) in the spinal cord of DFP-treated hens after 1, 5, 10, and 20 days). There was increase in CaM kinase II alpha subunit level after 10 and 20 days of treatment, and decrease in PKC level at 1-day and 20-days time periods in spinal cord mitochondria. In contrast, the cerebrum, which is resistant to DFP-induced axonal degeneration, did not show change in PKA and CaM Kinase II levels at any time period DFP post-administration. No alteration was found in the protein levels of PP1, PP2A, and PP2B at any time period. An early induction in PKA, which is an important protein kinase in signal transduction, followed by that of CaM kinase might be contributing towards the development of OPIDN in DFP-treated hens.
Mol Cell Biochem 2001 Apr
PMID:Enhanced activity and level of protein kinase A in the spinal cord supernatant of diisopropyl phosphorofluoridate (DFP)-treated hens. Distribution of protein kinases and phosphatases in spinal cord subcellular fractions. 1145 76

Loss-of-function mutations in the cystatin B (Cstb) gene cause a neurological disorder known as Unverricht-Lundborg disease (EPM1) in human patients. Mice that lack Cstb provide a mammalian model for EPM1 by displaying progressive ataxia and myoclonic seizures. We analyzed RNAs from brains of Cstb-deficient mice by using modified differential display, oligonucleotide microarray hybridization and quantitative reverse transcriptase polymerase chain reaction to examine the molecular consequences of the lack of Cstb. We identified seven genes that have consistently increased transcript levels in neurological tissues from the knockout mice. These genes are cathepsin S, C1q B-chain of complement (C1qB), beta2-microglobulin, glial fibrillary acidic protein (Gfap), apolipoprotein D, fibronectin 1 and metallothionein II, which are expected to be involved in increased proteolysis, apoptosis and glial activation. The molecular changes in Cstb-deficient mice are consistent with the pathology found in the mouse model and may provide clues towards the identification of therapeutic points of intervention for EPM1 patients.
Hum Mol Genet 2001 Sep 01
PMID:Cystatin B-deficient mice have increased expression of apoptosis and glial activation genes. 1155 22

Altered function of the ubiquitin pathway has been implicated in the etiology of neurodegeneration. For example, gracile axonal dystrophy (gad) mutant mice, which harbor a deletion within the gene encoding ubiquitin C-terminal hydrolase L1 (Uch-L1), display sensory ataxia followed by posterior paralysis and lethality. We previously showed that mice homozygous for a targeted deletion of the related Uch-L3 gene are indistinguishable from wild-type. To assess whether the two hydrolases have redundant function, we generated mice homozygous for both Uch-L1gad and Uch-L3Delta3-7. The double homozygotes weigh 30% less than single homozygotes and display an earlier onset of lethality, possibly due to dysphagia, a progressive loss in the ability to swallow food. This is consistent with histological analysis that revealed axonal degeneration of the nucleus tractus solitarius (NTS) and area postrema (AP) of the medulla. The NTS is essential for central nervous system control of swallowing. The double homozygotes also display a more severe axonal degeneration of the gracile tract of the medulla and spinal cord than had been observed in Uch-L1gad single homozygotes. In addition, degeneration of dorsal root ganglia cell bodies was detected in both the double homozygotes and Uch-L3Delta3-7 single homozygotes. Given that both Uch-L1gad and Uch-L3Delta3-7 single homozygotes display distinct degenerative defects that are exacerbated in the double homozygotes, we conclude that Uch-L1 and Uch-L3 have both separate and overlapping functions in the maintenance of neurons of the gracile tract, NTS and AP. This study is the first to successfully document dysphagia in the mouse and is a potentially valuable resource for understanding human neurodegenerative disorders that cause swallowing defects.
Hum Mol Genet 2001 Sep 01
PMID:Loss of Uch-L1 and Uch-L3 leads to neurodegeneration, posterior paralysis and dysphagia. 1155 33

The beta isoforms of phospholipase C (PLCbetas) are thought to mediate signals from metabotropic glutamate receptor subtype 1 (mGluR1) that is crucial for the modulation of synaptic transmission and plasticity. Among four PLCbeta isoforms, PLCbeta4 is one of the two major isoforms expressed in cerebellar Purkinje cells. The authors have studied the roles of PLCbeta4 by analyzing PLCbeta4 knockout mice, which are viable, but exhibit locomotor ataxia. Their cerebellar histology, parallel fiber synapse formation, and basic electrophysiology appear normal. However, developmental elimination of multiple climbing fiber innervation is clearly impaired in the rostral portion of the cerebellar vermis, where PLCbeta4 mRNA is predominantly expressed in the wild-type mice. In the adult, long-term depression is deficient at parallel fiber to Purkinje cell synapses in the rostral cerebellum of the PLCbeta4 knockout mice. The impairment of climbing fiber synapse elimination and the loss of long-term depression are similar to those seen in mice defective in mGluR1, Galphaq, or protein kinase C. Thus, the authors' results strongly suggest that PLCbeta4 is part of a signaling pathway, including the mGluR1, Galphaq and protein kinase C, which is crucial for both climbing fiber synapse elimination in the developing cerebellum and long-term depression induction in the mature cerebellum.
Mol Neurobiol 2001 Feb
PMID:Roles of phospholipase Cbeta4 in synapse elimination and plasticity in developing and mature cerebellum. 1164 44

Multiple system atrophy is an adult onset neurodegenerative disease, featuring parkinsonism, ataxia, and autonomic failure, in any combination. The condition is relentlessly progressive and responds poorly to treatment. Death occurs on average six to seven years after the onset of symptoms. No familial cases of multiple system atrophy have been reported, and no environmental factors have been robustly implicated as aetiological factors. However, analytical epidemiological studies are hampered because the condition is relatively rare. The discovery of the glial cytoplasmic inclusion (GCI) in 1989 helped to define multiple system atrophy as a clinicopathological entity, and drew attention to the prominent, if not primary, role played by the oligodendrocyte in the pathogenesis of the condition. Subsequently, GCIs were shown to be positive for alpha-synuclein, with immunostaining for this protein indicating that white matter pathology was more widespread than had previously been recognised. The presence of alpha-synuclein in GCIs provides a link with Parkinson's disease, dementia with Lewy bodies, and neurodegeneration with brain iron accumulation, type 1 (or Hallervorden-Spatz syndrome), in which alpha-synuclein is also found within Lewy bodies. This has led to the term "synucleinopathy" to embrace this group of conditions. The GCIs of multiple system atrophy contain a range of other cytoskeletal proteins. It is unknown how fibrillogenesis occurs, and whether there is primary oligodendrocytic dysfunction, which then disrupts the neurone/axon as a consequence of the glial pathology, or whether the oligodendrocytic changes merely represent an epiphenomenon. Further research into this devastating condition is urgently needed to improve our understanding of the pathogenesis, and also to produce new treatment approaches.
Mol Pathol 2001 Dec
PMID:Multiple system atrophy: cellular and molecular pathology. 1172 18

Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disorder characterized by ataxia and selective neuronal cell loss caused by the expansion of a translated CAG repeat encoding a polyglutamine tract in ataxin-7, the SCA7 gene product. To gain insight into ataxin-7 function and to decipher the molecular mechanisms of neurodegeneration in SCA7, a two-hybrid assay was performed to identify ataxin-7 interacting proteins. Herein, we show that ataxin-7 interacts with the ATPase subunit S4 of the proteasomal 19S regulatory complex. The ataxin-7/S4 association is modulated by the length of the polyglutamine tract whereby S4 shows a stronger association with the wild-type allele of ataxin-7. We demonstrate that endogenous ataxin-7 localizes to discrete nuclear foci that also contain additional components of the proteasomal complex. Immunohistochemical analyses suggest alterations either of the distribution or the levels of S4 immunoreactivity in neurons that degenerate in SCA7 brains. Immunoblot analyses demonstrate reduced levels of S4 in SCA7 cerebella without evident alterations in the levels of other proteasome subunits. These results suggest a role for S4 and ubiquitin-mediated proteasomal proteolysis in the molecular pathogenesis of SCA7.
Hum Mol Genet 2001 Nov 15
PMID:Association of ataxin-7 with the proteasome subunit S4 of the 19S regulatory complex. 1173 47


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