chk-YB-1b, a Y-box binding protein activates transcription from rat alpha1(I) procollagen gene promoter.
Type-I collagen, the predominant component of extracellular matrix, is a triple-helical protein consisting of two alpha1 polypeptides and one alpha2 polypeptide. Expression of alpha1 and alpha2 procollagen genes is co-ordinately regulated under both normal and various pathological conditions. However, the basis of this co-ordinate regulation is not well known. YB-1b, a Y-box protein, has been shown to bind to the polypyrimidine tract present in the alpha2 procollagen gene. Here, we show that chk-YB-1b, a YB-1 homologue, binds in a single-strand-sequence-specific manner to the highly conserved pyrimidine-rich sequences in both alpha1(I) and alpha2(I) procollagen promoters from different species, as demonstrated by electrophoretic-mobility-shift assays and by DNaseI footprinting experiments. Transiently transfected and retrovirally expressed antisense oligonucleotides directed against chk-YB-1b specifically inhibited the alpha1(I) procollagen promoter-driven transcription in cultured fibroblasts. Considering these data and the fact that the chk-YB-1b binding site is one of the few sites between alpha1(I) and alpha2(I) procollagen promoters that is conserved from chicken to human, it is proposed that chk-YB-1b may be involved in co-ordinate expression of these two collagen genes.
Dhalla
A K
AK
Division of Cardiology, Department of Internal Medicine, School of Medicine, University of Missouri-Columbia, Columbia, MO 65212, USA.
Ririe
S S
SS
Swamynathan
S K
SK
Weber
K T
KT
Guntaka
R V
RV
D000818:Animals; D001665:Binding Sites; D002645:Chickens; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D020319:Oligodeoxyribonucleotides, Antisense; D011347:Procollagen / Q000235:genetics*; D011401:Promoter Regions, Genetic; D051381:Rats; D012190:Retroviridae / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D011347:Procollagen; D014157:Transcription Factors; C486170:Y-box homology protein, Gallus gallus; C486169:Ybx1 protein, rat