K. Miao et al., EFFECT OF ACETALDEHYDE ON SP1 BINDING AND ACTIVATION OF THE MOUSE ALPHA(2)(I) COLLAGEN PROMOTER, Archives of biochemistry and biophysics, 341(1), 1997, pp. 140-152
Acetaldehyde activates the mouse alpha(2)(I) collagen promoter and thi
s effect is mediated in part by increased binding of nuclear factor I
(NF-I). Additional mechanisms may exist since deletions in the promote
r upstream to the NF-I binding site prevented enhancement by acetaldeh
yde. Three adjacent areas of binding by nuclear proteins from activate
d hepatic stellate cells were identified at -568 to -554 (region 1), -
542 to -518 (region 2), and -473 to -453 (region 3) of the promoter us
ing DNase I protection analyses. Multiple DNA-protein complexes were f
ormed in electrophoretic mobility shift assays with oligonucleotide pr
obes specifying the three regions. Sp1 and NF-I bound to all three reg
ions, while Sp3 bound to region 2. Acetaldehyde decreased nuclear prot
ein binding to all three regions. Mutations of regions 1, 2, and 3 red
uced basal activity of the promoter and inhibited acetaldehyde stimula
tion in transfected stellate cells. Acetaldehyde inhibited the stimula
tory effect of the Sp1 vector pPacSp1 on the promoter in transfected D
rosophila cells. In conclusion, three regions of Sp1 binding were iden
tified and are required for optimal activity of the alpha(2)(I) collag
en promoter, Sp1 is required for basal activity of the alpha(2)(I) col
lagen promoter; however, the enhancing effect of acetaldehyde on the p
romoter is not mediated by Sp1. (C) 1997 Academic Press.