THE RECEPTOR TYROSINE KINASES OF THE TRK FAMILY - THE HIGH-AFFINITY NEUROTROPHIN RECEPTORS

The neurotrophins of the NGF family are involved in regulating neurona l differentiation, growth and survival. Their action is mediated by th e members of the Trk family of receptors tyrosine kinases. However, th ey also bind to another receptor, p75(LNGFR), whose role remains contr oversial. The Trk receptors, predominantly expressed in the nervous sy stem, are rather unique in that they have multiple isoforms (some non catalytic and others with inserts in the catalytic kinase domain) that might have distinct physiological roles. Analysis of mice carrying nu ll mutations for the neurotrophins and their receptors should provide valuable informations for our understanding of the function of these f actors and their possible use in the treatment of various types of neu rological diseases.