Tyrosine phosphorylation in early embryonic growth cones

摘要: A large and growing body of evidence suggests that the regulation tyrosine phosphorylation is important in induction axon growth. We have examined subcellular distribution enzymes regulating early embryonic brain, employing a preparation isolated growth cone particles (GCPs). Because developmental age well-characterized nature our tissue source, GCP offers some advantages over those described previously. As was found with other GCPs, GCPs had relatively high levels both growth-associated protein GAP-43 intracellular kinase pp60c-arc. In addition, we total activity phosphatase were concentrated two- to threefold relative neuronal membrane fraction. Two nonreceptor kinases, YES FYN, similar degree as seen for SRC. expression brain three using quantitative ELISA Western blot analysis. Our results show like SRC, reaches peak development, declines thereafter. contrast, peaks later, remains adult brain. Immunofluorescence staining FYN expressed by neurons glia, possibly precursor cells. implicate multiple kinases well phosphatases function. concentration cones combined its an role development.