scholarly journals Interaction of a lens cell transcription factor with the proximal domain of the mouse gamma F-crystallin promoter.

1991 ◽  
Vol 11 (3) ◽  
pp. 1531-1537 ◽  
Author(s):  
Q R Liu ◽  
M Tini ◽  
L C Tsui ◽  
M L Breitman
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Transcriptional Activator ◽  
Tata Box ◽  
Specific Expression ◽  
Nuclear Factors ◽  
Gamma Crystallin ◽  
Lens Cells ◽  
Lens Cell

The elements regulating lens-specific expression of the mouse gamma F-crystallin gene were examined. Here we show that mouse gamma F-crystallin sequences -67 to +45 contain a low basal level of lens-specific promoter activity and that sequences -67 to -25, which are highly conserved among different gamma-crystallin genes, are able to function as a strong transcriptional activator when duplicated and placed upstream of the TATA box. We also show that nuclear factors from lens and nonlens cells are able to form different complexes with sequences centered at -46 to -36 and demonstrate that binding of the factor from lens cells correlates with lens-specific promoter activity of the mouse gamma F-crystallin gene.

Interaction of a lens cell transcription factor with the proximal domain of the mouse gamma F-crystallin promoter

1991 ◽  
Vol 11 (3) ◽  
pp. 1531-1537
Author(s):  
Q R Liu ◽  
M Tini ◽  
L C Tsui ◽  
M L Breitman
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Transcriptional Activator ◽  
Tata Box ◽  
Specific Expression ◽  
Nuclear Factors ◽  
Gamma Crystallin ◽  
Lens Cells ◽  
Lens Cell

The elements regulating lens-specific expression of the mouse gamma F-crystallin gene were examined. Here we show that mouse gamma F-crystallin sequences -67 to +45 contain a low basal level of lens-specific promoter activity and that sequences -67 to -25, which are highly conserved among different gamma-crystallin genes, are able to function as a strong transcriptional activator when duplicated and placed upstream of the TATA box. We also show that nuclear factors from lens and nonlens cells are able to form different complexes with sequences centered at -46 to -36 and demonstrate that binding of the factor from lens cells correlates with lens-specific promoter activity of the mouse gamma F-crystallin gene.

scholarly journals Regulation of human prohormone convertase 2 promoter activity by the transcription factor EGR-1

1997 ◽  
Vol 328 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Erik JANSEN ◽  
A. Y. Torik AYOUBI ◽  
M. P. Sandra MEULEMANS ◽  
Wim J. M. VAN DE VEN
Keyword(s):  
Transcription Factor ◽  
Promoter Region ◽  
Promoter Activity ◽  
Secretory Pathway ◽  
Tata Box ◽  
Proximal Promoter ◽  
Prohormone Convertase ◽  
Specific Expression ◽  
Proximal Promoter Region ◽  
Prohormone Convertase 2

Prohormone convertases are involved in the tissue-specific endoproteolytic processing of prohormones and neuropeptide precursors within the secretory pathway. In the present study, we have isolated genomic clones comprising the 5ʹ-terminal region of the human prohormone convertase 2 (PC2) gene and established characteristics of the PC2 promoter region. The proximal promoter region is very G+C-rich and does not contain a canonical TATA box or a CAAT box. Transient expression assays with a set of human PC2 gene fragments containing progressive 5ʹ deletions demonstrate that the proximal promoter region is capable of directing high levels of neuroendocrine-specific expression of reporter gene constructs. In addition, we show that the transcription factor EGR-1 interacts with two distinct elements within the proximal human PC2 promoter region. Transfection experiments also demonstrate that EGR-1 is able to enhance PC2 promoter activity.

The restricted promoter activity of the liver transcription factor hepatocyte nuclear factor 3 beta involves a cell-specific factor and positive autoactivation

1992 ◽  
Vol 12 (2) ◽  
pp. 552-562
Author(s):  
L Pani ◽  
X B Quian ◽  
D Clevidence ◽  
R H Costa
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Binding Activity ◽  
Specific Factor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Cell Type ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific

The transcription factor hepatocyte nuclear factor 3 (HNF-3) is involved in the coordinate expression of several liver genes. HNF-3 DNA binding activity is composed of three different liver proteins which recognize the same DNA site. The HNF-3 proteins (designated alpha, beta, and gamma) possess homology in the DNA binding domain and in several additional regions. To understand the cell-type-specific expression of HNF-3 beta, we have defined the regulatory sequences that elicit hepatoma-specific expression. Promoter activity requires -134 bp of HNF-3 beta proximal sequences and binds four nuclear proteins, including two ubiquitous factors. One of these promoter sites interacts with a novel cell-specific factor, LF-H3 beta, whose binding activity correlates with the HNF-3 beta tissue expression pattern. Furthermore, there is a binding site for the HNF-3 protein within its own promoter, suggesting that an autoactivation mechanism is involved in the establishment of HNF-3 beta expression. We propose that both the LF-H3 beta and HNF-3 sites play an important role in the cell-type-specific expression of the HNF-3 beta transcription factor.

scholarly journals The β-cell specific transcription factor Nkx6.1 inhibits glucagon gene transcription by interfering with Pax6

2007 ◽  
Vol 403 (3) ◽  
pp. 593-601 ◽  
Author(s):  
Benoit R. Gauthier ◽  
Yvan Gosmain ◽  
Aline Mamin ◽  
Jacques Philippe
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Gene Transcription ◽  
Promoter Activity ◽  
Islet Cells ◽  
Gene Activation ◽  
Physical Interaction ◽  
Specific Expression

The transcription factor Nkx6.1 is required for the establishment of functional insulin-producing β-cells in the endocrine pancreas. Overexpression of Nkx6.1 has been shown to inhibit glucagon gene expression while favouring insulin gene activation. Down-regulation resulted in the opposite effect, suggesting that absence of Nkx6.1 favours glucagon gene expression. To understand the mechanism by which Nkx6.1 suppresses glucagon gene expression, we studied its effect on the glucagon gene promoter activity in non-islet cells using transient transfections and gel-shift analyses. In glucagonoma cells transfected with an Nkx6.1-encoding vector, the glucagon promoter activity was reduced by 65%. In BHK21 cells, Nkx6.1 inhibited by 93% Pax6-mediated activation of the glucagon promoter, whereas Cdx2/3 and Maf stimulations were unaltered. Although Nkx6.1 could interact with both the G1 and G3 element, only the former displayed specificity for Nkx6.1. Mutagenesis of the three potential AT-rich motifs within the G1 revealed that only the Pax6-binding site preferentially interacted with Nkx6.1. Chromatin immunoprecipitation confirmed interaction of Nkx6.1 with the glucagon promoter and revealed a direct competition for binding between Pax6 and Nkx6.1. A weak physical interaction between Pax6 and Nkx6.1 was detected in vitro and in vivo suggesting that Nkx6.1 predominantly inhibits glucagon gene transcription through G1-binding competition. We suggest that cell-specific expression of the glucagon gene may only proceed when Nkx6.1, in combination with Pdx1 and Pax4, are silenced in early α-cell precursors.

Lens-specific promoter activity of a mouse gamma-crystallin gene

1985 ◽  
Vol 5 (9) ◽  
pp. 2221-2230
Author(s):  
S Lok ◽  
M L Breitman ◽  
A B Chepelinsky ◽  
J Piatigorsky ◽  
R J Gold ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Promoter Activity ◽  
Gene Families ◽  
Initiation Site ◽  
Water Soluble ◽  
Specific Mechanism ◽  
Gamma Crystallin ◽  
Specific Proteins ◽  
Lens Cell ◽  
Vertebrate Eye

Crystallins are the major water-soluble proteins in vertebrate eye lenses. These lens-specific proteins are encoded by several gene families, and their expression is differentially regulated during lens cell differentiation. Here we show that a cloned mouse gamma-crystallin promoter is active in lens explants derived from 14-day-old chicken embryos but inactive in a variety of cells of non-lens origin. We also show that sequences required for proper utilization of this promoter are contained between nucleotide positions -392 and +47 relative to the transcription initiation site; deletion of sequences from positions -392 to -171 completely abolishes promoter activity. Since chickens do not have gamma-crystallin genes, the expression of a mouse gamma-crystallin promoter in chicken lens cells suggests that different classes of crystallin genes may be regulated by common lens tissue-specific mechanism(s) independent of species.

scholarly journals Transcription factor Sp1 activates involucrin promoter activity in non-epithelial cell types

1999 ◽  
Vol 337 (3) ◽  
pp. 507-512 ◽  
Author(s):  
Eric B. BANKS ◽  
James F. CRISH ◽  
Richard L. ECKERT
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Regulatory Region ◽  
Epidermal Keratinocytes ◽  
Specific Expression ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Transcription Factor Sp1 ◽  
293 Cells ◽  
Strong Activator

The gene for human involucrin (hINV) is selectively expressed in stratifying epithelial cells lining external body surfaces. Previously, we characterized the hINV promoter 5´ distal regulatory region (DRR) located between nt -2473 and -2088 upstream of the transcription start site. This region is required for optimal hINV gene expression. The DRR contains weak and strong activator elements. The strong activator comprises AP1- and Sp1-binding sites that combine to drive high-level promoter expression in human keratinocytes. Here we show that the hINV promoter is expressed in a cell-specific manner in vitro and that the DRR contains elements that are partly responsible for cell-type-specific expression of hINV. hINV promoter activity is barely detectable in 3T3 fibroblasts or HEK-293 human embryonic kidney cells. Reporter plasmids containing the full-length promoter or the isolated DRR can, however, be activated in 3T3 and HEK-293 cells by co-transfection with a plasmid encoding the transcription factor Sp1. Consistently with the lower hINV promoter activity, immunoblotting studies indicate that Sp1 protein levels are lower in 3T3 and HEK-293 cells than in human epidermal keratinocytes. Increased Sp1 protein in transfected 3T3 cells and HEK-293 cells correlates with increased promoter activity. In addition, Sp1 transfection activates the expression of the endogenous gene for hINV in HEK-293 cells. These studies suggest that Sp1 might have a role in cell-specific expression of hINV.

scholarly journals Transactivation of the Mouse Sulfonylurea Receptor I Gene by BETA2/NeuroD

2002 ◽  
Vol 16 (5) ◽  
pp. 1097-1107 ◽  
Author(s):  
Ji-Won Kim ◽  
Victor Seghers ◽  
Jang-Hyeon Cho ◽  
Yup Kang ◽  
Soyeon Kim ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Hela Cells ◽  
Promoter Activity ◽  
Dominant Negative Mutant ◽  
Sulfonylurea Receptor ◽  
Β Cell ◽  
Specific Expression ◽  
Tissue Specific ◽  
Tissue Specific Expression ◽  
Hit Cells

Abstract The sulfonylurea receptor 1 (SUR1) plays a key role in regulation of insulin secretion in pancreatic β-cells. In this study we investigated the mechanism for tissue-specific expression of the SUR1 gene. A −138/−20 fragment exhibited basal promoter activity while the −660/−20 fragment contained a regulatory element for tissue-specific expression of the mouse SUR1 gene. A pancreatic β-cell-specific transcription factor, BETA2 (β-cell E box transcription factor)/NeuroD, enhanced the promoter activity of the −660/−20 fragment in cooperation with E47. Coexpression of a dominant negative mutant of BETA2/NeuroD, BETA2(1–233), repressed the promoter activity of the −660/−20 fragment. BETA2/NeuroD bound specifically to the E3 element located at −141. The E3 sequence in a heterologous context conferred transactivation by BETA2/NeuroD in HeLa and HIT cells. Mutation of E3 eliminated the stimulatory effect of BETA2/NeuroD. Unlike BETA2/NeuroD, neurogenin 3 (ngn3) could not activate the E3 element in HeLa cells. Overexpression of ngn3 concomitantly increased expression of BETA2/NeuroD and SUR1 in HIT cells but not in HeLa cells. These results indicate that BETA2/NeuroD induces tissue-specific expression of the SUR1 gene through the E3 element. These results also suggest that E3 is specific for BETA2/NeuroD, and the stimulatory effect of ngn3 in HIT cells may require factors specifically expressed in HIT cells.

scholarly journals The restricted promoter activity of the liver transcription factor hepatocyte nuclear factor 3 beta involves a cell-specific factor and positive autoactivation.

1992 ◽  
Vol 12 (2) ◽  
pp. 552-562 ◽  
Author(s):  
L Pani ◽  
X B Quian ◽  
D Clevidence ◽  
R H Costa
Keyword(s):  
Transcription Factor ◽  
Promoter Activity ◽  
Binding Activity ◽  
Specific Factor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Cell Type ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific

The transcription factor hepatocyte nuclear factor 3 (HNF-3) is involved in the coordinate expression of several liver genes. HNF-3 DNA binding activity is composed of three different liver proteins which recognize the same DNA site. The HNF-3 proteins (designated alpha, beta, and gamma) possess homology in the DNA binding domain and in several additional regions. To understand the cell-type-specific expression of HNF-3 beta, we have defined the regulatory sequences that elicit hepatoma-specific expression. Promoter activity requires -134 bp of HNF-3 beta proximal sequences and binds four nuclear proteins, including two ubiquitous factors. One of these promoter sites interacts with a novel cell-specific factor, LF-H3 beta, whose binding activity correlates with the HNF-3 beta tissue expression pattern. Furthermore, there is a binding site for the HNF-3 protein within its own promoter, suggesting that an autoactivation mechanism is involved in the establishment of HNF-3 beta expression. We propose that both the LF-H3 beta and HNF-3 sites play an important role in the cell-type-specific expression of the HNF-3 beta transcription factor.

scholarly journals Lens-specific promoter activity of a mouse gamma-crystallin gene.

1985 ◽  
Vol 5 (9) ◽  
pp. 2221-2230 ◽  
Author(s):  
S Lok ◽  
M L Breitman ◽  
A B Chepelinsky ◽  
J Piatigorsky ◽  
R J Gold ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Promoter Activity ◽  
Gene Families ◽  
Initiation Site ◽  
Water Soluble ◽  
Specific Mechanism ◽  
Gamma Crystallin ◽  
Specific Proteins ◽  
Lens Cell ◽  
Vertebrate Eye

Crystallins are the major water-soluble proteins in vertebrate eye lenses. These lens-specific proteins are encoded by several gene families, and their expression is differentially regulated during lens cell differentiation. Here we show that a cloned mouse gamma-crystallin promoter is active in lens explants derived from 14-day-old chicken embryos but inactive in a variety of cells of non-lens origin. We also show that sequences required for proper utilization of this promoter are contained between nucleotide positions -392 and +47 relative to the transcription initiation site; deletion of sequences from positions -392 to -171 completely abolishes promoter activity. Since chickens do not have gamma-crystallin genes, the expression of a mouse gamma-crystallin promoter in chicken lens cells suggests that different classes of crystallin genes may be regulated by common lens tissue-specific mechanism(s) independent of species.

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