RAT AND CHICKEN S-REX NSP MESSENGER-RNA - NUCLEOTIDE-SEQUENCE OF MAINTRANSCRIPTS AND EXPRESSION OF SPLICE VARIANTS IN RAT-TISSUES/

Two main transcripts of the s-rex/NSP gene are generated by different promoter usage and differential splicing in neuronal and endocrine tis sues of higher vertebrates, suggesting that the encoded proteins funct ion in neuroendocrine secretion. To know more about the structure, exp ression and evolution of this new gene, we have cloned full-length cDN As for both 1.5 kb and 3.5 kb transcripts from rat and chicken brain c DNA libraries. Sequence analysis has revealed structures within the 3' -UTR that are conserved in these mRNAs and human NSP mRNA and that cou ld be involved in specific compartmentalization of s-rex/NSP mRNA in n euronal cells. An additional transcript generated by differential spli cing of internal exons has been cloned from a rat DRG library. Low lev els of s-rex/NSP mRNAs have been detected in some non-neuroendocrine t issues, although substantial levels of a unique transcript have been f ound in rat testis. By RT-PCR analysis, other tissue-specific transcri pts that are products of rare splicing events have been revealed.