ISSN:
1432-0878
Keywords:
Key words Protein phosphorylation
;
Protein kinase-C
;
Neural crest
;
Cell migration
;
Cell invasion
;
Second messengers
;
Quail (Coturnix coturnix japonica)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Epithelio-mesenchymal transition, which involves the re-organisation of cell-cell adhesion molecules and the actin cytoskeleton, can be induced in embryonic neural epithelium in vitro by protein kinase-C inhibitors. A non-inhibitory analogue, BIM V, and potent inhibitors of other kinases are not active. This suggests a central role for C-kinases, although the powerful specific C-kinase inhibitors BIM I and Ro 31–8220 show lower than expected activity. Co-inhibition by several kinases is unlikely to account for this, since no potentiation occurs when these are combined with potent inhibitors of other kinases. BIM I and Ro 31–8220 strongly inhibit only conventional calcium-regulated C-kinases; this and the lack of effect of TMB-8, which inhibits calcium release, suggests that novel and/or atypical isoforms are involved. Various potentiators and activators of conventional and novel C-kinases have no obvious effect alone and fail to reduce the effect of staurosporine, suggesting that atypical C-kinases are critical. The presence of C-kinase isoforms in the E2 embryonic neural tissues has been probed on Western blots, revealing immunoreactivity for the atypical isoforms ι (or λ) and ζ and the α, γ, ɛ and μ isoforms. Immunofluorecent localisation on sections of embryos has shown the widespread distribution of conventional and novel isoforms but only the atypical isoforms λ and ζ are enriched at the apical margins of the neural and other epithelia; they overlap with the cell-cell adhesion molecule N-cadherin and with F-actin. Thus, epithelio-mesenchymal transition in the embryonic neural epithelium in vitro is induced by inhibiting protein kinase activity, probably via an atypical protein kinase-C; atypical protein kinase-C isoforms are present in the tissue at the appropriate developmental stage and subcellular site in cells capable of epithelio-mesenchymal transition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004410051225
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