Schwann cells of the myelin-forming phenotype express neurofilament protein NF-M.
Open Access
- 15 July 1992
- journal article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 118 (2), 397-410
- https://doi.org/10.1083/jcb.118.2.397
Abstract
Immature Schwann cells of the rat sciatic nerve can differentiate into myelin-forming or non-myelin-forming cells. The factors that influence this divergent development are unknown but certain markers such as galactocerebroside distinguish the two cell populations at an early stage of Schwann cell differentiation. Because myelination requires extensive changes in cell morphology, we have investigated the composition and structure of the Schwann cell cytoskeleton at a time when these cells become committed to myelination. Here we show that Schwann cells express a cytoskeletal protein of M(r) 145 before diverging into the myelin-forming path, i.e., before they acquire cell-surface galactocerobroside. The p145 protein has the characteristics of an intermediate filament (IF) protein and immunoelectron microscopy shows that it colocalizes with vimentin, which suggests that these two proteins can coassemble into IFs. Elevated intracellular cAMP levels, which can mimic some of the early effects of axons on Schwann cell differentiation, induced p145 synthesis, therefore, we conclude that myelin-forming Schwann cells express this protein at a very early stage in their development. Immunological comparisons with other IF proteins revealed a close similarity between p145 and the neurofilament protein NF-M; the identification of p145 as NF-M was confirmed by isolating and sequencing a full-length clone from a Schwann cell cDNA library. These data demonstrate that Schwann cells remodel their IFs by expressing NF-M before acquiring the myelin-forming phenotype and that IF proteins of the neurofilament-type are not restricted to neurons in the vertebrate nervous system.Keywords
This publication has 53 references indexed in Scilit:
- The effects of cAMP on differentiation of cultured Schwann cells: progression from an early phenotype (04+) to a myelin phenotype (P0+, GFAP-, N-CAM-, NGF-receptor-) depends on growth inhibition.The Journal of cell biology, 1991
- Schwann cell precursors and their developmentGlia, 1991
- Role for the oligodendrocyte cytoskeleton in myelinationJournal of Neuroscience Research, 1989
- Expression of NF-L and NF-M in fibroblasts reveals coassembly of neurofilament and vimentin subunits.The Journal of cell biology, 1989
- Postnatal development of rat peripheral nerves: an immunohistochemical study of membrane lipids common to non-myelin forming Schwann cells, myelin forming Schwann cells and oligodendrocytesDevelopmental Brain Research, 1987
- Looking for a functionNature, 1987
- Linkage Between Axonal Ensheathment and Basal Lamina Production by Schwann CellsAnnual Review of Neuroscience, 1986
- Axolemma-enriched fractions isolated from PNS and CNS are mitogenic for cultured Schwann cellsDevelopmental Brain Research, 1982
- Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.Proceedings of the National Academy of Sciences of the United States of America, 1979
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970