Localization of tyrosine-phosphorylated proteins in cultured mouse dorsal root ganglion neurons

Citation
M. Shirasu et al., Localization of tyrosine-phosphorylated proteins in cultured mouse dorsal root ganglion neurons, J ORTHOP R, 16(6), 1998, pp. 690-696
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
JOURNAL OF ORTHOPAEDIC RESEARCH
ISSN journal
0736-0266 → ACNP
Volume
16
Issue
6
Year of publication
1998
Pages
690 - 696
Database
ISI
SICI code
0736-0266(199811)16:6<690:LOTPIC>2.0.ZU;2-3
Abstract
The present study, using confocal laser scanning microscopy and immunoelect ron microscopy, examined the intracellular localization of tyrosine-phospho rylated proteins in cultured mouse dorsal root ganglion neurons with specia l reference to their growth cones. The growth cone is the specialized struc ture formed at the growing tip of the axon; characteristically highly motil e with filopodia on the surface, it is responsible for the extension and gu idance of the neurites to the appropriate targets during nerve regeneration . It has been suggested that protein-tyrosine phosphorylation plays an impo rtant role in the intracellular signal transduction that regulates the exte nsion and motility of growth cones. By fluorescence immunocytochemistry, ph osphotyrosine immunoreactivity was found in the growth cones and neurites. Some of the filopodia exhibited strong immunoreactivity at their tips. By i mmunoelectron microscopy, a large number of immunogold particles (gold part icles conjugated to the secondary antibody) were seen to be distributed in the cytoplasm and some were observed on the plasma membrane in the growth c ones, whereas in the neurites the density of immunogold particles was the s ame in the axoplasm as on the plasma membranes. These findings suggest that in the growth cones phosphotyrosines might mainly be involved in intracell ular signaling for maintaining their high motility whereas in the neurites they might mostly be associated with the receptor proteins at the plasma me mbrane for adhesion as well as for growth of neurites. Thus, tyrosine phosp horylation might contribute to different functions for growth cones and neu rites.