The synaptophysin-encoding gene in rat and man is specifically transcribed in neuroendocrine cells.

摘要: Abstract Synaptophysin (SY) is an integral membrane protein of presynaptic small (30–80-nm) translucent vesicles also present in dispersed neuroendocrine cells. As the occurrence this type vesicle specific for two major pathways differentiation, neuronal and neuroendocrine-epithelial information on regulation SY synthesis should contribute to understanding regulatory principles common both pathways. Isolation comparison complete rat human single-copy genes showed that despite difference size (16kb vs. 13 kb man) intron/exon boundaries are precisely conserved. Surprisingly, intron VI located 3'-noncoding region species. The transcriptional start point, as determined by primer extension S1-nuclease protection analyses pheochromocytoma-derived PC 12 cells brain, mapped a site 27 nt 5' first methionine codon. Unexpectedly, upstream devoid any TATA or CAAT boxes, but shows instead typical features ‘housekeeping’ i.e., G + C-rich islands four Spl-binding motifs. Using ‘nuclear run-on’ assays, we have identified examples which regulated at level. Reporter gene constructs approx. 1.2kb immediate contains promoter/enhancer elements were, however, insufficient confer cell-type expression, whereas sequences farther were able suppress thymidine kinase promoter activity cell-type-dependent fashion.