S. Desouza et al., ROLE OF THE BZIP TRANSCRIPTION FACTOR IREBF1 IN THE NGF INDUCTION OF STROMELYSIN-1 (TRANSIN) GENE-EXPRESSION IN PC12 CELLS, Journal of molecular neuroscience, 8(3), 1997, pp. 243-255
Stromelysin-1 (ST-1) is one of the most nerve growth factor-(NGF) resp
onsive gene products expressed in PC12 cells. In previous work, we ide
ntified a novel NGF-responsive element in the proximal promoter region
of the ST-1 gene that participates in this induction, and showed that
it bound a protein present in the nuclei of PC12 cells. Here, we iden
tify a transcription factor that specifically recognizes this regulato
ry element-the interferon-response element binding factor-1 (IREBF1),
a member of the basic leucine zipper gene family. We show that IREBF1
is constitutively expressed in PC12 cells and that overexpression of I
REBF1 augments NGF-responsive ST-1 gene regulation, but does not affec
t basal levels of expression. On the other hand, expression of a mutat
ed form of this transcription factor lacking the DNA binding domain at
tenuated NGF responsiveness, without affecting basal levels of express
ion. These data suggest that IREBF1 is part of the NGF-responsive tran
scriptional machinery necessary for the expression of ST-1 in PC12 cel
ls.