A MEMBRANE-BOUND HEPARAN-SULFATE PROTEOGLYCAN THAT IS TRANSIENTLY EXPRESSED ON GROWING AXONS IN THE RAT-BRAIN

Monoclonal antibodies were raised to membrane-bound proteoglycans deri ved from rat brain and three monoclonal antibodies that recognized a 2 00-kDa heparan sulfate proteoglycan (designated H5-PG) with a core gly coprotein of 140 kDa were obtained. The expression of H5-PG was spatia lly and temporally regulated in the central nervous system. In the cer ebellar cortex, H5-PG was associated mainly with the actively growing parallel fibers of granule cells. The expression was abruptly down-reg ulated in parallel with the formation of synapses on dendrites of Purk inje cells, In the cerebral cortex, the proteoglycan was widely distri buted throughout the cortex. The temporal pattern of expression was si milar to that in the cerebellar cortex; the peak level of expression w as observed during the period from postnatal days 0 to 20 when neurito genesis and synaptogenesis occur most extensively in the rat cerebral cortex. H5-PG in the central nervous system disappeared prior to adult hood except in the olfactory bulb. High-level expression was recognize d on the olfactory nerves and glomeruli, where the renewal of both axo ns and synapses is occurring constantly. The data suggest that H5-PG i s a glycoconjugate on axonal surface that is involved in axonal outgro wth and/or synaptogenesis. (C) 1996 Wiley-Liss, Inc.