INTRACELLULAR COMPARTMENTALIZATION OF 2 DIFFERENTIALLY SPLICED S-REX-NSP MESSENGER-RNAS IN NEURONS

Using a subtractive hybridization technique directed to cloning transc ripts with compartmentalized distributions within cerebral cortex neur ons, we have isolated rat s-rex mRNAs that are analogues of the human neuroendocrine-specific NSP gene transcripts. Differential splicing pr oduces two main s-rex mRNA that have different regional distributions in the developing and mature rat nervous system. In certain population s of adult brain neurons, most of s-rex(s) mRNA and a substantial amou nt of s-rex(b) mRNA are localized to the axonal pole of the cell body. The localization of S-Rex/NSP proteins in these neurons suggests that s-rex mRNA compartmentalization targets the encoded proteins to speci fic regions of the neuron.