Nonreceptor protein tyrosine kinases associated with neuronal development.

Protein tyrosine kinases (PTKs) of the nonreceptor class have been implicated in neurite outgrowth during development and regeneration of the central and peripheral nervous systems. Nonreceptor PTK encoded by mammalian proto-oncogenes (c-src, fyn, c-yes, c-abl) and their homologs in Drosophila exhibit patterns of expression and activities that suggest functions in axonal or dendritic outgrowth. These kinases may link cell surface recognition events elicited by the binding of cell adhesion molecules, extracellular matrix, or growth factors with intracellular signaling pathways in neuronal cells. The structure, localization, developmental regulation, and function of these molecules is reviewed.