New mechanisms of neurite outgrowth and TrkA receptor activation/signaling

The paper we recently published in PNAS, entitled “Neurite outgrowth induced by NGF or L1CAM via activation of the TrkA receptor is sustained also by the exocytosis of enlargeosomes” (Colombo et al., 2014), reported studies carried out in clones isolated from the PC12 line, frequently employed as a neuronal model. Two original and integrated findings were obtained, concerning the vesicle traffic and fusion processes necessary for neurite outgrowth, and the activation by the adhesion protein L1CAM of the receptor TrkA. The latter tyrosine kinase was widely considered as a receptor activated exclusively by the neurotrophin NGF. Both these findings provide an explanation to results previously obtained in our and other laboratories.