<i>In Vitro</i> Synthesis of the Myelin Basic Proteins: Subcellular Site of Synthesis

Campagnoni, Anthony T.; Carey, G D; Yu, Yi‐Tao

doi:10.1111/j.1471-4159.1980.tb11197.x

Cited by 47 publications

(28 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early evidence for the asymmetric distri bution of MBP mRNAs within the oligoden drocyte came from biochemical studies showing an enrichment of MBP mRNA in myelin fractions [23], even though the MBPs appeared to be synthesized on free ribosomes [22,23]. Recently, several laboratories have reported results consistent with this notion using in situ hybridization histochemistry with radioactive probes in vivo and in vitro [10,[13][14][15][16][17].…”

Section: Discussionsupporting

confidence: 62%

“…However, interpretation of these studies, performed with radiolabeled probes, has de pended heavily upon differences in the distri bution patterns between PLP and MBP mRNAs (i.e. 'clustered' vs. 'diffuse'), and the consistency of these results with other cell biological and biochemical data [21][22][23], The diffuse pattern of in situ hybridization obtained with MBP probes only occasionally allowed assignment of grains to oligoden drocyte processes [16,17].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatial Distribution of mRNAs for Myelin Proteins in Primary Cultures of Mouse Brain

Amur‐Umarjee¹,

Hall²,

Campagnoni³

1990

Dev Neurosci

View full text Add to dashboard Cite

A nonradioactive in situ hybridization procedure was employed to study the distribution of mRNAs for myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG) and 2'',3''-cyclic nucleotide 3''-phosphodiesterase (CNP) in oligodendrocytes in primary cultures of mouse brain. This procedure provided good cellular localization and allowed rapid detection of the mRNAs with low backgrounds. Gradual movement of MBP mRNAs from oligodendrocyte somas into processes was observed with time in culture. The MBP mRNAs were observed to be distributed in an asymmetric fashion within the somas and cell processes. Antigalactocerebroside staining indicated the presence of oligodendrocyte processes prior to movement of MBP mRNA, suggesting that the presence of processes alone was insufficient for translocation of MBP mRNAs. The mRNAs for PLP and MAG remained confined to the oligodendrocyte somas at all times in culture at least up to 28 days. While most of the CNP mRNAs were observed to be associated with the perikarya of oligodendrocytes, in less than 1 % of these cells the presence of CNP mRNA in the processes was evident. This suggests that there may exist a subset of oligodendrocytes in which the translocation of these messages occurs.

show abstract

Section: Discussionsupporting

confidence: 62%

Section: Introductionmentioning

confidence: 99%

Spatial Distribution of mRNAs for Myelin Proteins in Primary Cultures of Mouse Brain

Amur‐Umarjee¹,

Hall²,

Campagnoni³

1990

Dev Neurosci

View full text Add to dashboard Cite

show abstract

“…The role of MBP in the morphogenesis of the myelin membrane is unclear, but studies of the mutant mouse shiverer in which there is a large deletion in the MBP structural gene have correlated the myelin deficit in the CNS with the absence of MBP (Readhead et al, 1987). MBP is a peripheral membrane protein synthesized on free ribosomes (Campagnoni et al, 1980). The presence of MBP mRNA in the processes of the oligodendrocytes was first reported by Colman et al (1982), who identified MBP mRNA in a myelin fraction obtained by subcellular fractionation.…”

Section: Introductionmentioning

confidence: 99%

Spatial distribution of myelin basic protein mRNA and polypeptide in Quaking oligodendrocytes in culture

Barbarese

1991

J of Neuroscience Research

View full text Add to dashboard Cite

In the CNS, myelin is formed from the expansion of oligodendrocyte processes. In order to study myelin assembly in the hypomyelinating mutant mouse quaking (qk), cultures of oligodendrocytes were established from affected and control animals. The cytoarchitecture of the oligodendrocytes was analyzed by performing morphometric measurements after immunostaining with antitubulin. The results indicate that the gross morphology of the processes is similar in control and mutant cells. The localization of the message for the myelin structural component, myelin basic protein (MBP), was examined by in situ hybridization. In control oligodendrocytes, 80% of MBP mRNA is found in the processes. In contrast, only 23% of MBP mRNA is localized to these structures in the mutant; the majority of MBP mRNA remains in the cell body. The mutant cells are capable of distributing mRNAs to the periphery as shown by the presence of tubulin mRNA in their processes. MBP polypeptide was visualized by immunofluorescence and found in the perikaryon, processes and membranous expansions of the control cells. In the mutant, it is largely confined to the perikaryon, reflecting the distribution of the mRNA. These results suggest that the localization of MBP polypeptide is achieved by restricting the distribution of its mRNA, and that MBP assembly into the myelin membrane occurs in the processes. This step appears to be blocked in qk oligodendrocytes in culture.

show abstract

“…The two other species (21.5 kDa and 17 kDa) differ from the L and S proteins only in that they contain near their amino termini an additional polypeptide segment that is common to both (4). It has been shown that the CNS MBPs represent four distinct primary translation products, and from this it was inferred that they are encoded by four distinct mRNAs (5,6). The precise genetic relationship between the four MBP polypeptides of the CNS has not been elucidated, nor is it known if the corresponding polypeptides found in CNS and PNS are products of the same gene.…”

mentioning

confidence: 99%

Small basic proteins of myelin from central and peripheral nervous systems are encoded by the same gene.

Mentaberry¹,

Adesnik²,

Atchison³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Peripheral nervous system (PNS) and central nervous system (CNS) rodent myelins, which are produced by different cell types, share common morphological and functional characteristics although their major integral membrane proteins are completely different. Both types of myelin however, contain sets of four myelin basic proteins (MBPs), which share similar immunochemical and electrophoretic properties. We have isolated and characterized cDNA clones corresponding to the rat mRNAs encoding the small MBPs (SMBPs) found in both CNS and PNS myelin. Sequence analysis of these clones indicate that SMBPs in both divisions of the nervous system are encoded by the same nucleotide sequences, which suggests that they are the products of the same gene expressed in both oligodendrocyte and Schwann cells. In dot-blot hybridization experiments with the CNS SMBP cDNA as a probe, it was shown that there is a 20-fold higher level of MBP mRNA in a CNS myelin fraction than in total brainstem mRNA. It also was found that in optic and sciatic nerves, which contain oligodendrocytes and Schwann cells respectively, there are higher levels (4-fold and 2-fold, respectively) of MBP mRNA than in brainstem. Blot-hybridization experiments showed that a probe derived from the coding region of the rat SMBP cDNA hybridizes to an homologous mRNA (=2.6 kilobases) present in human optic nerve, which is not detectable with a probe derived from the 3' untranslated region. This conservation of coding-region sequences is in accord with the highly homologous amino acid sequences reported for the MBPs in the two species.Myelin sheaths that envelope axons in the central nervous system (CNS) and the peripheral nervous system (PNS) are derived from the plasma membranes of specialized glial cells. In the CNS, the myelin-forming cell is the oligodendrocyte, a cell that during myelination sends out numerous cytoplasmic processes, each of which myelinates a single internodal segment. Thus, a single oligodendrocyte may support up to 50 internodes in different axons that may be some distance away from the cell body (1). By contrast, in the PNS, each internodal segment is myelinated by one Schwann cell, and this remains closely apposed to the myelinated axon.Although PNS and CNS rodent myelins have very similar morphological features and functional characteristics, their major integral membrane proteins are different. However, both classes of myelin contain similar sets of four peripheral membrane polypeptides, the myelin basic proteins (MBPs). CNS and PNS MBPs have similar immunochemical and electrophoretic properties, although in the PNS the polypeptides are less abundant (2).The four MBPs of the CNS show striking sequence relatedness. The two major ones (L and S, 18.5 kDa and 14 kDa, respectively) represent =90% of the total complement of MBPs and have the same amino acid sequence, except for an internal deletion of 40 amino acids near the carboxyl terminus of S (3). The two other species (21.5 kDa and 17 kDa) differ from the L and S proteins only in that...

show abstract

In Vitro Synthesis of the Myelin Basic Proteins: Subcellular Site of Synthesis

Cited by 47 publications

References 23 publications

Spatial Distribution of mRNAs for Myelin Proteins in Primary Cultures of Mouse Brain

Spatial Distribution of mRNAs for Myelin Proteins in Primary Cultures of Mouse Brain

Spatial distribution of myelin basic protein mRNA and polypeptide in Quaking oligodendrocytes in culture

Small basic proteins of myelin from central and peripheral nervous systems are encoded by the same gene.

Contact Info

Product

Resources

About