A NOVEL NERVE GROWTH FACTOR-RESPONSIVE ELEMENT IN THE STROMELYSIN-1 (TRANSIN) GENE THAT IS NECESSARY AND SUFFICIENT FOR GENE-EXPRESSION IN PC12 CELLS

Stromelysin-1 (ST-1) is an extracellular matrix metalloproteinase whose expression is transcriptionally regulated by nerve growth factor (NGF) in the PC12 rat pheochromocytoma cell line. In this paper, we define sequences in the proximal ST-1 promoter that contain a novel NGF-responsive element(s). We show that this cis-acting promoter element can bind nuclear proteins from both untreated and NGF-treated PC12 cells in a specific and saturable manner and is sufficient to confer NGF-inducibility to a heterologous promoter. At least a portion of this NGF-responsive element lies within a 12-base pair region between positions -241 and -229 of the ST-1 promoter and bears no sequence homology to other known transcriptional elements. In contrast to what has been reported for fibroblasts, an AP1 site centered around position -68 does not seem to be involved in the growth factor regulation of ST-1 in PC12 cells. These results suggest that the NGF regulation of ST-1 gene expression involves different promoter elements, and possibly different transcription factors, from that described for ST-1 induction by other growth factors.