Spatiotemporal expression of noncatalytic TrkC NC2 isoform during early and late CNS neurogenesis: a comparative study with TrkC catalytic and p75NTR receptors

Authors

  • Bénédicte Menn,

    1. CNRS UMR 146, Institut Curie, CNRS UMR 146, Régulations Cellulaires et Oncogénèse, Centre Universitaire, Bât. 110, 91405 Orsay Cedex, France
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    • *Current address: Laboratory of Neurogenesis, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
  • Serge Timsit,

    1. INMED, INSERM U29 Route de Luminy BP13, 13273 Marseille Cedex 09, France
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    • Current address: Neurotech, Bâtiment Génopole-Industries, 4 rue Pierre Fontaine, 91000 Evry, France
  • Alfonso Represa,

    1. INMED, INSERM U29 Route de Luminy BP13, 13273 Marseille Cedex 09, France
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  • Stéphanie Mateos,

    1. CNRS UMR 146, Institut Curie, CNRS UMR 146, Régulations Cellulaires et Oncogénèse, Centre Universitaire, Bât. 110, 91405 Orsay Cedex, France
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  • Georges Calothy,

    1. CNRS UMR 146, Institut Curie, CNRS UMR 146, Régulations Cellulaires et Oncogénèse, Centre Universitaire, Bât. 110, 91405 Orsay Cedex, France
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  • Fabienne Lamballe

    1. CNRS UMR 146, Institut Curie, CNRS UMR 146, Régulations Cellulaires et Oncogénèse, Centre Universitaire, Bât. 110, 91405 Orsay Cedex, France
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: Dr Fabienne Lamballe, as above.
E-mail: Fabienne.Lamballe@curie.u-psud.fr

Abstract

The TrkC subfamily of primary high-affinity neurotrophin-3 receptors is composed of catalytic (kinase-containing; TrkC K) and noncatalytic (TrkC NC) isoforms generated by alternative splicing. We previously reported the presence of the mouse noncatalytic TrkC NC2 isoform in regions of neuronal differentiation [Menn, B., Timsit, S., Calothy, G. & Lamballe, F. (1998) J. Comp. Neurol., 401, 47–64]. In order to gain insight into specific roles for TrkC NC2 receptors during CNS neurogenesis, we compared its distribution with that of its catalytic counterparts and the p75NTR receptor in in vivo and in vitro model systems of early and late neuronal differentiation. We found that TrkC NC2 expression coincided with the exit of neuronal progenitors from the cell cycle and was maintained in differentiated cerebellar neurons. We also showed that, whilst TrkC K receptors were expressed both in mitotic and postmitotic cells, TrkC NC2 was present only in differentiating neural stem cell progeny, suggesting its involvement in neuronal and glial cell differentiation. During neuritogenesis of primary neocortical neurons, both TrkC isoforms as well as p75NTR were located in axonal and dendritic processes. However, whilst these various receptors were present in the same neuronal compartments, TrkC NC2 distribution was specifically restricted to distinct areas of extending neurites. Taken together, these findings suggest that spatiotemporal localization of the noncatalytic receptor could account for specific local effects of neurotrophin-3.

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