Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.4.37 (CNPase)
539 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Copper deficiency induced by a low copper diet in three generations of rats was associated with substantial reductions in the yield of myelin (56%), brain weight (11%), and body weight (43%) in F2 generation rat pups nursed by their own copper-deficient mothers. The composition of the purified myelin was not different from that of controls in the content of individual proteins, lipids, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity, or GM1 ganglioside. The major myelin-associated glycoprotein (mGP) was consistently shifted slightly toward higher apparent molecular weight in the copper-deficient animals. Postnatal copper replacement by a foster mother produced a normal yield of myelin per gram of brain tissue, but failed to reverse the deficiency of brain and body growth. After copper replacement in a copper-deficient mother's diet prior to conception, a subsequent litter showed correction of all abnormalities found in her previous litters. The results suggest that copper is essential for myelin formation and general growth during critical periods in development.
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PMID:Hypomyelination in copper-deficient rats. Prenatal and postnatal copper replacement. 125 45

We have isolated and characterized coated vesicles from bovine white matter and compared them to those isolated from gray matter. The virtual absence of synaptic vesicle antigens in the white matter coated vesicles indicates they are distinct from those found in gray matter and from vesicles derived from synaptic membranes. The white matter coated vesicles also lack compact myelin components, e.g., the myelin proteolipid, galactocerebroside, and sulfatides, as well as the periaxolemmal myelin marker myelin-associated glycoprotein. On the other hand, these vesicles contain 2',3'-cyclic nucleotide phosphohydrolase. The vesicles also contain high levels of plasmolipin, a protein present in myelin and oligodendrocytes. Plasmolipin was found to be four to five times higher in white matter coated vesicles than in gray matter coated vesicles. Based on western blot quantitation, the concentration of plasmolipin in white matter coated vesicles is 3-4% of the vesicle bilayer protein. These studies indicate that a significant proportion of coated vesicles from white matter may be derived from unique membrane domains of the myelin complex or oligodendroglial membrane, which are enriched in plasmolipin.
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PMID:Identification of plasmolipin as a major constituent of white matter clathrin-coated vesicles. 154 72

A monoclonal antibody (8-18C5) directed against myelin/oligodendrocyte glycoprotein (MOG) induced demyelination in aggregating brain cell cultures. With increasing doses of anti-MOG antibody in the presence of complement, myelin basic protein (MBP) concentration decreased in a dose-related manner. A similar, albeit less pronounced, effect was observed on specific activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase. In the absence of complement, anti-MOG antibody did not induce detectable demyelination. In contrast to the effect of anti-MOG antibody and as expected, anti-MBP antibody did not demyelinate aggregating brain cell cultures in the presence of complement. These results provide additional support to the suggestion that MOG, a quantitatively minor myelin component located on the external side of the myelin membrane, is a good target antigen for antibody-induced demyelination. Indeed, they show that a purified anti-MOG antibody directed against a single epitope on the glycoprotein can produce demyelination, not only in vivo as previously shown, but also in cultures. Such an observation has not been made with polyclonal antisera raised against purified myelin proteins like MBP and proteolipid protein, the major protein components of the myelin membrane, or myelin-associated glycoprotein. These observations may have important implications regarding the possible role of anti-MOG antibodies in demyelinating diseases.
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PMID:Demyelination induced in aggregating brain cell cultures by a monoclonal antibody against myelin/oligodendrocyte glycoprotein. 169 40

Using an immunoblotting technique, we investigated changes in the concentrations of microtubule-associated protein 2, 200-kDa neurofilament, tubulin, myelin-associated glycoprotein, and 2':3'-cyclic nucleotide 3'-phosphodiesterase in the brains of 40 rats following occlusion of the left middle cerebral artery or sham operation. Compared with those 4 hours after surgery, concentrations of all proteins decreased significantly in the left hemisphere 3 days after surgery (p less than 0.01). Microtubule-associated protein 2 was the most susceptible to ischemia, and its mean +/- SEM concentration decreased to 23 +/- 9.4% of that in concurrent sham-operated controls. Degradation products of microtubule-associated protein 2 and myelin-associated glycoprotein were detected on the blots. Furthermore, in the contralateral hemisphere (where calpain might be activated), concentrations of these two proteins decreased to 57 +/- 12.0% and 83 +/- 4.3% of those in concurrent sham-operated controls, respectively, 3 days after surgery. Changes in the concentrations of cerebral proteins in the contralateral hemisphere are important for understanding clinical symptoms not attributable solely to the ipsilateral lesion following a focal cerebral stroke.
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PMID:Changes in the concentrations of cerebral proteins following occlusion of the middle cerebral artery in rats. 211 75

The myelin-associated glycoprotein (MAG) was quantitated in the CNS and PNS of quaking mice and the levels compared to the levels of myelin basic protein (MBP) and 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) activity. In the brainstems of 36-day-old quaking mice, MBP, MAG, and CNPase were reduced to 12, 16, and 29% of control levels, respectively. In the sciatic nerves of the 36-day-old quaking mice, MBP and CNPase were 38 and 75% of control levels, respectively, whereas the concentration of MAG was unchanged or slightly increased. Similar quantitative results were obtained for the sciatic nerves and spinal roots of 7-month-old quaking mice. Immunoblots showed that the principal MAG band from the brainstems, sciatic nerves, and spinal roots of the quaking mice had a higher than normal apparent Mr. In addition, there was a minor component reacting with anti-MAG antiserum in the brainstems of the quaking mice that had a slightly lower Mr than control MAG and was not detected in the normal mice. The results for the quaking mice are compared with those from similar studies on other mutants with dysmyelination of the CNS and PNS.
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PMID:Myelin-associated glycoprotein in the central and peripheral nervous system of quaking mice. 243 56

In order to study the biosynthesis of myelin-associated proteins in Schwann cells, we have induced proliferation of cultured Schwann cells from neonatal rat sciatic nerve by transformation with Simian Virus 40 (SV40). Homogeneous transformed Schwann cell lines were established by single cell cloning. The transformed phenotype of these Schwann cell lines was determined by both integration of SV40 viral DNA sequences into the cellular genome and active synthesis of the large T antigen of SV40. In addition, similar transformations with SV40 virus containing a temperature-sensitive mutation in the large T gene yielded Schwann cell lines with transformed phenotype which were temperature-sensitive. In this report, we demonstrate that these SV40-transformed Schwann cells actively synthesize myelin-specific sulfatide, myelin-associated glycoprotein (MAG) and the glial cell marker 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). Despite the expression of MAG and CNPase, these Schwann cells did not synthesize PO the major protein of peripheral myelin. Since a substantial amount of normal size PO mRNA was present in these transformed Schwann cells, the lack of PO synthesis was apparently not the result of a deficiency of transcription. These results are consistent with the possibility that the regulation of PO synthesis differs from that of MAG and CNPase synthesis and that PO synthesis may be controlled at the post-transcriptional level.
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PMID:Biosynthesis of myelin-associated proteins in simian virus 40 (SV40)-transformed rat Schwann cell lines. 244

We have analyzed the effects of genetic and epigenetic factors on the steady-state levels of myelin basic protein mRNA and polypeptides during development of mouse oligodendrocytes in culture. Oligodendrocytes were characterized by immunofluorescent staining with antibodies for the following markers: galactocerebroside, myelin basic protein, proteolipid protein, myelin-associated glycoprotein and 2',3'-cyclic nucleotide phosphohydrolase. Oligodendrocytes expressing one or more of these markers first appeared at 3 days in culture and increased to a maximum of 1.5 X 10(5) per brain around 6 days, after which the number remained constant up to 31 days. In medium containing fetal calf serum, accumulation of myelin basic protein polypeptides was delayed relative to in vivo in cultures derived from C57BL/6J, BALB/cJ and DBA/2J inbred mice, but not in cultures derived from C3H/HeJ and AKR/J inbred mice. In medium containing serum from other species or in serum substitute, the temporal expression of myelin basic protein polypeptides in cultures from all the inbred strains was contemporaneous with that in brain. Northern hybridization analysis indicated that the steady-state level of myelin basic protein-specific mRNA in all cultures was regulated similarly to in vivo suggesting that the delayed expression of myelin basic protein polypeptides in some cultures was due to translational and/or post-translational regulation. Analysis of myelin basic protein expression in cultures from informative hybrid and recombinant inbred strains indicated that translational or post-translational expression of myelin basic protein requires trans-acting factors, the inducibility of which is controlled by multiple genetic determinants which segregate independently and are expressed additively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of myelin basic protein mRNA and polypeptides in mouse oligodendrocytes in culture: differential regulation by genetic and epigenetic factors. 245 46

Patients with Pelizaeus-Merzbacher disease (PM), hemizygous mice with the jimpy mutation (jp/Y), and hemizygous rats with X-linked myelin deficiency (md/Y) share a profound lack of proteolipid protein (PLP) in their central nervous systems (CNS). The peripheral nervous system is normal. These X-linked disorders are associated with or actually caused by the lack of normal oligodendrocytes. Vibratome sections of brain were incubated with antisera to myelin basic protein (MBP), myelin-associated glycoprotein (MAG), 2':3'-cyclic-nucleotide 3'-phosphodiesterase (CNP) (EC 3.1.4.37), PLP, a synthetic PLP-peptide, glial fibrillary acidic protein (GFAP), and transferrin. Reaction product was developed by sequential incubation with biotinylated second antibodies, the avidin-biotin-peroxidase complex (ABC), and diaminobenzidine (DAB) plus hydrogen peroxide as chromogenic substrates. In PM, jp/Y and md/Y, islands of myelin-like structures were revealed by antisera to MBP, MAG, and CNP. Reaction product after application of anti-PLP was absent. Reaction product after anti-PLP-peptide was restricted to infrequent bizarre cells possibly representing abnormal oligodendroglia. The lack of oligodendrocytes in jp/Y and md/Y could also be confirmed by immunocytochemistry for transferrin.
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PMID:Comparative immunocytochemistry of Pelizaeus-Merzbacher disease, the jimpy mouse, and the myelin-deficient rat. 245 99

We analyzed the location and abundance of transcripts for the 4 CNS myelin protein genes, myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), and 2',3'-cyclic nucleotide phosphohydrolase (CNP), in the mouse cervical spinal cord from the time of rapid myelination until adulthood (8-45 d). In the white matter, maximal levels of transcripts were found for each of the myelin genes at the peak of myelination (8 d). Total MBP and PLP mRNAs stayed high until 20 d and showed a minor decrease thereafter. In contrast, MAG and the MBP exon 2 containing transcripts (coding for the 21.5 and 17 kDa MBP isoforms) decreased sharply between 8 and 20 d, suggesting that high levels of these transcripts are needed primarily during the initiation of myelination. CNP transcripts were less abundant, maintained high expression until 20 d, and then decreased sharply. PLP, MAG, and CNP transcripts were clustered in the oligodendrocyte cell body, while MBP mRNAs were scattered throughout the cell body and processes. In contrast to the white matter, all these myelin specific transcripts in the gray matter showed a marked increase from 8 to 20 d, as did the number of oligodendrocytes identified by CNP immunostaining. MAG transcripts were found in white matter and in satellite and other oligodendrocytes of the gray matter but not in neurons identified by their expression of neurofilament transcripts. The results of our quantitative in situ hybridization study are in good agreement with those of previous molecular studies and provide new information on the cellular and topographic distribution of myelin-specific mRNAs during myelination.
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PMID:In situ hybridization analysis of myelin gene transcripts in developing mouse spinal cord. 246 47

Fresh lesions in the brain and spinal cord of patients with multiple sclerosis who died shortly after the onset of symptoms were examined immunocytochemically for myelin and oligodendrocyte antigens that are known to be sequentially expressed during normal development. Cells with oligodendrocyte-like morphology that appear in large numbers throughout fresh lesions after acute myelin breakdown and before new myelin formation were found to express galactocerebroside, carbonic anhydrase, and 2',3'-cyclic nucleotide 3'-phosphohydrolase but not myelin-associated glycoprotein or myelin basic protein. They also exhibit intense surface reactivity for a carbohydrate epitope associated with the family of cell adhesion molecules recognized by the monoclonal antibody HNK-1. With the onset of remyelination and the appearance of myelin-associated glycoprotein, myelin basic proteins, CNP, and the HNK-1 epitope is newly formed myelin sheaths, perikaryon CNP and HNK-1 reactivity diminished. A possible oligodendrocyte precursor cell in the form of a large HNK-1 positive glial fibrillary acidic protein negative glial cell was observed among interfascicular oligodendrocytes in white matter bordering these hypercellular plaques. Because a similar progression in the expression of CNP and the HNK-1 epitope occurs during normal oligodendrocyte differentiation, these observations are additional evidence that extensive oligodendrocyte regeneration occurs in some plaques early in the course of the disease. The finding of large numbers of immature oligodendrocytes, presumably expressing many developmentally restricted antigens not normally present in the mature nervous system, in plaques at a particular stage in their evolution may be important in understanding why remyelination eventually fails in multiple sclerosis.
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PMID:Multiple sclerosis. Oligodendrocyte proliferation and differentiation in fresh lesions. 281 Dec 98


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