SHARPS - MAMMALIAN ENHANCER-OF-SPLIT-RELATED AND HAIRY-RELATED PROTEINS COUPLED TO NEURONAL STIMULATION (VOL 9, PG 460, 1997)

In the mammalian central nervous system, a diverse group of basic heli x-loop-helix (bHLH) proteins is involved in the determination of proge nitor cells and, subsequently, in regulating neuronal differentiation. Here we report the identification of a novel subfamily of bHLH protei ns, defined by two mammalian enhancer-of-split-and hairy-related prote ins, termed SHARP-1 and SHARP-2. In contrast to known bHLH genes, dete ctable transcription of SHARP genes begins at the end of embryonic dev elopment marking differentiated neurons that have reached a final posi tion, and increases as postnatal development proceeds, in the adult, S HARP genes are expressed in subregions of the CNS that have been assoc iated with adult plasticity. in PC12 cells, a model system to study ne urite outgrowth, SHARP genes can be induced by NGF with the kinetics o f an immediate-early gene. Similarly, within 1 h after the administrat ion of kainic acid in vivo, SHARP-2 is induced in neurons throughout t he rat cerebral coaler. This suggests that neuronal bHLH proteins are also involved in the ''adaptive'' changes of mature CNS neurons which are coupled to glutamatergic stimulation.