scholarly journals chk-YB-1b, a Y-box binding protein activates transcription from rat α1(I) procollagen gene promoter

1998 ◽  
Vol 336 (2) ◽  
pp. 373-379 ◽  
Author(s):  
Arvinder K. DHALLA ◽  
Seth S. RIRIE ◽  
Shivalingappa K. SWAMYNATHAN ◽  
Karl T. WEBER ◽  
Ramareddy V. GUNTAKA
Keyword(s):  
Type I Collagen ◽  
Gene Promoter ◽  
Type I ◽  
Mobility Shift ◽  
Cultured Fibroblasts ◽  
Predominant Component ◽  
Helical Protein ◽  
Dnasei Footprinting ◽  
Collagen Genes ◽  
Electrophoretic Mobility Shift Assays

Type-I collagen, the predominant component of extracellular matrix, is a triple-helical protein consisting of two α1 polypeptides and one α2polypeptide. Expression of α1 and α2 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 α2 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 α1(I) and α2(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 α1(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 α1(I)and α2(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.

scholarly journals Functional analysis of cis-acting DNA sequences controlling transcription of the human type I collagen genes.

1990 ◽  
Vol 265 (22) ◽  
pp. 13351-13356
Author(s):  
S Boast ◽  
M W Su ◽  
F Ramirez ◽  
M Sanchez ◽  
E V Avvedimento
Keyword(s):  
Functional Analysis ◽  
Dna Sequences ◽  
Type I Collagen ◽  
Type I ◽  
Cis Acting ◽  
Human Type ◽  
Collagen Genes

scholarly journals Silencing of the Gene for the α-Subunit of Human Chorionic Gonadotropin by the Embryonic Transcription Factor Oct-3/4

1997 ◽  
Vol 11 (11) ◽  
pp. 1651-1658 ◽  
Author(s):  
Limin Liu ◽  
Douglas Leaman ◽  
Michel Villalta ◽  
R. Michael Roberts
Keyword(s):  
Transcription Factor ◽  
Binding Site ◽  
Gene Promoter ◽  
Site Directed Mutagenesis ◽  
Mobility Shift ◽  
Α Subunit ◽  
Choriocarcinoma Cells ◽  
Human Choriocarcinoma Cells ◽  
Electrophoretic Mobility Shift Assays ◽  
Jar Cells

Abstract CG is required for maintenance of the corpus luteum during pregnancy in higher primates. As CG is a heterodimeric molecule, some form of coordinated control must be maintained over the transcription of its two subunit genes. We recently found that expression of human CG β-subunit (hCGβ) in JAr human choriocarcinoma cells was almost completely silenced by the embryonic transcription factor Oct-3/4, which bound to a unique ACAATAATCA octameric sequence in the hCGβ gene promoter. Here we report that Oct-3/4 is also a potent inhibitor of hCG α-subunit (hCGα) expression in JAr cells. Oct-3/4 reduced human GH reporter expression from the −170 hCGα promoter in either the presence or absence of cAMP by about 70% in transient cotransfection assays, but had no effect on expression from either the −148 hCGα or the −99 hCGα promoter. Unexpectedly, no Oct-3/4-binding site was identified within the −170 to −148 region of the hCGα promoter, although one was found around position −115 by both methylation interference footprinting and electrophoretic mobility shift assays. Site-directed mutagenesis of this binding site destroyed the affinity of the promoter for Oct-3/4, but did not affect repression of the promoter. Therefore, inhibition of hCGα gene transcription by Oct-3/4 appears not to involve direct binding of this factor to the site responsible for silencing. When stably transfected into JAr cells, Oct-3/4 reduced the amounts of both endogenous hCGα mRNA and protein by 70–80%. Oct-3/4 is therefore capable of silencing both hCGα and hCGβ gene expression. We suggest that as the trophoblast begins to form, reduction of Oct-3/4 expression permits the coordinated onset of transcription from the hCGα and hCGβ genes.

Control of Type I Collagen Genes in Scleroderma and Normal Fibroblasts

1990 ◽  
Vol 16 (1) ◽  
pp. 109-123
Author(s):  
Benoit de Crombrugghe ◽  
Tuula Vuorio ◽  
Gerard Karsenty
Keyword(s):  
Type I Collagen ◽  
Type I ◽  
Collagen Genes

Regulation of collagen I gene expression by ras

1992 ◽  
Vol 12 (10) ◽  
pp. 4714-4723
Author(s):  
J L Slack ◽  
M I Parker ◽  
V R Robinson ◽  
P Bornstein
Keyword(s):  
Type I Collagen ◽  
The Body ◽  
Transformed Cells ◽  
Type I ◽  
Mrna Levels ◽  
Oncogenic Ras ◽  
Genes Encoding ◽  
Flanking Region ◽  
Collagen Genes ◽  
I Gene

Although transformation of rodent fibroblasts can lead to dramatic changes in expression of extracellular matrix genes, the molecular basis and physiological significance of these changes remain poorly understood. In this study, we have investigated the mechanism(s) by which ras affects expression of the genes encoding type I collagen. Levels of both alpha 1(I) and alpha 2(I) collagen mRNAs were markedly reduced in Rat 1 fibroblasts overexpressing either the N-rasLys-61 or the Ha-rasVal-12 oncogene. In fibroblasts conditionally transformed with N-rasLys-61, alpha 1(I) transcript levels began to decline within 8 h of ras induction and reached 1 to 5% of control levels after 96 h. In contrast, overexpression of normal ras p21 had no effect on alpha 1(I) or alpha 2(I) mRNA levels. Nuclear run-on experiments demonstrated that the transcription rates of both the alpha 1(I) and alpha 2(I) genes were significantly reduced in ras-transformed cells compared with those in parental cells. In addition, the alpha 1(I) transcript was less stable in transformed cells. Chimeric plasmids containing up to 3.6 kb of alpha 1(I) 5'-flanking DNA and up to 2.3 kb of the 3'-flanking region were expressed at equivalent levels in both normal and ras-transformed fibroblasts. However, a cosmid clone containing the entire mouse alpha 1(I) gene, including 3.7 kb of 5'- and 4 kb of 3'-flanking DNA, was expressed at reduced levels in fibroblasts overexpressing oncogenic ras. We conclude that oncogenic ras regulates the type I collagen genes at both transcriptional and posttranscriptional levels and that this effect, at least for the alpha 1(I) gene, may be mediated by sequences located either within the body of the gene itself or in the distal 3'-flanking region.

scholarly journals Regulation of collagen I gene expression by ras.

1992 ◽  
Vol 12 (10) ◽  
pp. 4714-4723 ◽  
Author(s):  
J L Slack ◽  
M I Parker ◽  
V R Robinson ◽  
P Bornstein
Keyword(s):  
Type I Collagen ◽  
The Body ◽  
Transformed Cells ◽  
Type I ◽  
Mrna Levels ◽  
Oncogenic Ras ◽  
Genes Encoding ◽  
Flanking Region ◽  
Collagen Genes ◽  
I Gene

Although transformation of rodent fibroblasts can lead to dramatic changes in expression of extracellular matrix genes, the molecular basis and physiological significance of these changes remain poorly understood. In this study, we have investigated the mechanism(s) by which ras affects expression of the genes encoding type I collagen. Levels of both alpha 1(I) and alpha 2(I) collagen mRNAs were markedly reduced in Rat 1 fibroblasts overexpressing either the N-rasLys-61 or the Ha-rasVal-12 oncogene. In fibroblasts conditionally transformed with N-rasLys-61, alpha 1(I) transcript levels began to decline within 8 h of ras induction and reached 1 to 5% of control levels after 96 h. In contrast, overexpression of normal ras p21 had no effect on alpha 1(I) or alpha 2(I) mRNA levels. Nuclear run-on experiments demonstrated that the transcription rates of both the alpha 1(I) and alpha 2(I) genes were significantly reduced in ras-transformed cells compared with those in parental cells. In addition, the alpha 1(I) transcript was less stable in transformed cells. Chimeric plasmids containing up to 3.6 kb of alpha 1(I) 5'-flanking DNA and up to 2.3 kb of the 3'-flanking region were expressed at equivalent levels in both normal and ras-transformed fibroblasts. However, a cosmid clone containing the entire mouse alpha 1(I) gene, including 3.7 kb of 5'- and 4 kb of 3'-flanking DNA, was expressed at reduced levels in fibroblasts overexpressing oncogenic ras. We conclude that oncogenic ras regulates the type I collagen genes at both transcriptional and posttranscriptional levels and that this effect, at least for the alpha 1(I) gene, may be mediated by sequences located either within the body of the gene itself or in the distal 3'-flanking region.

scholarly journals Abnormal type I collagen metabolism by cultured fibroblasts in lethal perinatal osteogenesis imperfecta

1984 ◽  
Vol 217 (1) ◽  
pp. 103-115 ◽  
Author(s):  
J F Bateman ◽  
T Mascara ◽  
D Chan ◽  
W G Cole
Keyword(s):  
Osteogenesis Imperfecta ◽  
Cell Lines ◽  
Type I Collagen ◽  
The Other ◽  
Collagen Metabolism ◽  
Structural Defects ◽  
Collagen Molecule ◽  
Type I ◽  
Cultured Fibroblasts ◽  
Post Translational Modifications

Cultured skin fibroblasts from seven consecutive cases of lethal perinatal osteogenesis imperfecta (OI) expressed defects of type I collagen metabolism. The secretion of [14C]proline-labelled collagen by the OI cells was specifically reduced (51-79% of control), and collagen degradation was increased to twice that of control cells in five cases and increased by approx. 30% in the other two cases. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revealed that four of the OI cell lines produced two forms of type I collagen consisting of both normally and slowly migrating forms of the alpha 1(I)- and alpha 2(I)-chains. In the other three OI cell lines only the ‘slow’ alpha (I)′- and alpha 2(I)′-chains were detected. In both groups inhibition of the post-translational modifications of proline and lysine resulted in the production of a single species of type I collagen with normal electrophoretic migration. Proline hydroxylation was normal, but the hydroxylysine contents of alpha 1(I)′- and alpha 2(I)′-chains purified by h.p.l.c. were greater than in control alpha-chains. The glucosylgalactosylhydroxylysine content was increased approx. 3-fold while the galactosylhydroxylysine content was only slightly increased in the alpha 1(I)′-chains relative to control alpha 1(I)-chains. Peptide mapping of the CNBr-cleavage peptides provided evidence that the increased post-translational modifications were distributed throughout the alpha 1(I)′- and alpha 2(I)′-chains. It is postulated that the greater modification of these chains was due to structural defects of the alpha-chains leading to delayed helix formation. The abnormal charge heterogeneity observed in the alpha 1 CB8 peptide of one patient may reflect such a structural defect in the type I collagen molecule.

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