Co-expression of heparin-binding growth-associated molecule (HB-GAM) and N-syndecan (syndecan-3) in developing rat brain.

Biochemical and cell biological studies have previously identified N-syndecan as a neuronal cell surface receptor in neurite outgrowth induced by heparin-binding growth-associated molecule (HB-GAM). In the present study we have compared temporal and spatial expression patterns of N-syndecan and HB-GAM using Northern and Western blotting and immunohistochemistry. Expression of N-syndecan mRNA and protein peaks during the perinatal developmental stage of the brain in the same manner as the expression of HB-GAM mRNA and protein. In addition, both proteins are preferentially localized to fiber tracts of developing brain. We suggest that HB-GAM and N-syndecan form ligand-receptor complexes in developing axon tracts of brain.