Sequences containing the second-intron enhancer are essential for transcription of the human apolipoprotein B gene in the livers of transgenic mice

1994 ◽  
Vol 14 (4) ◽  
pp. 2243-2256
Author(s):  
A R Brooks ◽  
B P Nagy ◽  
S Taylor ◽  
W S Simonet ◽  
J M Taylor ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Transcriptional Activation ◽  
Apolipoprotein B ◽  
Regulatory Elements ◽  
Apob Gene ◽  
Specific Expression ◽  
Position Effects ◽  
Direct Transcription ◽  
Hepatic Expression ◽  
Human Apolipoprotein

To identify DNA sequence elements from the human apolipoprotein B (apoB) gene required for high-level, correct tissue-specific expression in transgenic mice, we made several constructs that included one or more of the key regulatory elements that were previously characterized with cultured liver-derived and intestine-derived cell lines. Our data show that the apoB promoter alone (-898 to +121) is not sufficient to direct transcription in transgenic mice. An enhancer located in the second intron is absolutely required to specify transcription by the homologous apoB promoter in the livers of transgenic mice; this enhancer does not direct transcription in the small intestines. Thus, the elements controlling transcriptional activation of the apoB gene in the liver and the intestine in vivo are distinct and separable. Analysis of the DNase I hypersensitivity of the integrated human transgenes in various lines of expressing and nonexpressing mice suggests that the formation of DH4, a strong hypersensitive site in intron 2, may be a prerequisite for hepatic expression of the apoB gene. Nuclear matrix association regions (MARs) of the apoB gene may play a role in transgene expression. Constructs including MAR sequences displayed higher levels of expression than those lacking them. However, these MARs did not completely insulate the associated transgenes from position effects.

scholarly journals Sequences containing the second-intron enhancer are essential for transcription of the human apolipoprotein B gene in the livers of transgenic mice.

1994 ◽  
Vol 14 (4) ◽  
pp. 2243-2256 ◽  
Author(s):  
A R Brooks ◽  
B P Nagy ◽  
S Taylor ◽  
W S Simonet ◽  
J M Taylor ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Transcriptional Activation ◽  
Apolipoprotein B ◽  
Regulatory Elements ◽  
Apob Gene ◽  
Specific Expression ◽  
Position Effects ◽  
Direct Transcription ◽  
Hepatic Expression ◽  
Human Apolipoprotein

To identify DNA sequence elements from the human apolipoprotein B (apoB) gene required for high-level, correct tissue-specific expression in transgenic mice, we made several constructs that included one or more of the key regulatory elements that were previously characterized with cultured liver-derived and intestine-derived cell lines. Our data show that the apoB promoter alone (-898 to +121) is not sufficient to direct transcription in transgenic mice. An enhancer located in the second intron is absolutely required to specify transcription by the homologous apoB promoter in the livers of transgenic mice; this enhancer does not direct transcription in the small intestines. Thus, the elements controlling transcriptional activation of the apoB gene in the liver and the intestine in vivo are distinct and separable. Analysis of the DNase I hypersensitivity of the integrated human transgenes in various lines of expressing and nonexpressing mice suggests that the formation of DH4, a strong hypersensitive site in intron 2, may be a prerequisite for hepatic expression of the apoB gene. Nuclear matrix association regions (MARs) of the apoB gene may play a role in transgene expression. Constructs including MAR sequences displayed higher levels of expression than those lacking them. However, these MARs did not completely insulate the associated transgenes from position effects.

scholarly journals The CD11b promoter directs high-level expression of reporter genes in macrophages in transgenic mice [published erratum appears in Blood 1995 Apr 1;85(7):1983]

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Transgene Expression ◽  
Heterologous Gene Expression ◽  
Myeloid Cells ◽  
Reporter Genes ◽  
Regulatory Elements ◽  
Specific Expression ◽  
High Level

Abstract CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.

scholarly journals Fast skeletal muscle-specific expression of a quail troponin I gene in transgenic mice.

1988 ◽  
Vol 8 (12) ◽  
pp. 5072-5079 ◽  
Author(s):  
P L Hallauer ◽  
K E Hastings ◽  
A C Peterson
Keyword(s):  
Skeletal Muscle ◽  
Transgenic Mice ◽  
Troponin I ◽  
Fiber Type ◽  
Regulatory Elements ◽  
Evolutionary Divergence ◽  
Mrna Levels ◽  
Fast Skeletal Muscle ◽  
Specific Expression ◽  
Exon 2

We have produced seven lines of transgenic mice carrying the quail gene encoding the fast skeletal muscle-specific isoform of troponin I (TnIf). The quail DNA included the entire TnIf gene, 530 base pairs of 5'-flanking DNA, and 1.5 kilobase pairs of 3'-flanking DNA. In all seven transgenic lines, normally initiated and processed quail TnIf mRNA was expressed in skeletal muscle, where it accumulated to levels comparable to that in quail muscle. Moreover, in the three lines tested, quail TnIf mRNA levels were manyfold higher in a fast skeletal muscle (gastrocnemius) than in a slow skeletal muscle (soleus). We conclude that the cellular mechanisms directing muscle fiber type-specific TnIf gene expression are mediated by cis-regulatory elements present on the introduced quail DNA fragment and that they control TnIf expression by affecting the accumulation of TnIf mRNA. These elements have been functionally conserved since the evolutionary divergence of birds and mammals, despite the major physiological and morphological differences existing between avian (tonic) and mammalian (twitch) slow muscles. In lines of transgenic mice carrying multiple tandemly repeated copies of the transgene, an aberrant quail TnIf transcript (differing from normal TnIf mRNA upstream of exon 2) also accumulated in certain tissues, particularly lung, brain, spleen, and heart tissues. However, this aberrant transcript was not detected in a transgenic line which carries only a single copy of the quail gene.

scholarly journals Specific expression of the human CD4 gene in mature CD4+ CD8- and immature CD4+ CD8+ T cells and in macrophages of transgenic mice

1994 ◽  
Vol 14 (2) ◽  
pp. 1084-1094
Author(s):  
Z Hanna ◽  
C Simard ◽  
A Laperrière ◽  
P Jolicoeur
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
Cd8 T Cells ◽  
Transcription Initiation ◽  
Critical Role ◽  
Regulatory Elements ◽  
T Cell Subsets ◽  
Double Positive ◽  
Specific Expression

The CD4 protein plays a critical role in the development and function of the immune system. To gain more insight into the mechanism of expression of the human CD4 gene, we cloned 42.2 kbp of genomic sequences comprising the CD4 gene and its surrounding sequences. Studies with transgenic mice revealed that a 12.6-kbp fragment of the human CD4 gene (comprising 2.6 kbp of 5' sequences upstream of the transcription initiation site, the first two exons and introns, and part of exon 3) contains the sequences required to support the appropriate expression in murine mature CD4+ CD8- T cells and macrophages but not in immature double-positive CD4+ CD8+ T cells. Expression in CD4+ CD8+ T cells was found to require additional regulatory elements present in a T-cell enhancer fragment recently identified for the murine CD4 gene (S. Sawada and D. R. Littman, Mol. Cell. Biol. 11:5506-5515, 1991). These results suggest that expression of CD4 in mature and immature T-cell subsets may be controlled by distinct and independent regulatory elements. Alternatively, specific regulatory elements may control the expression of CD4 at different levels in mature and immature T-cell subsets. Our data also indicate that mouse macrophages contain the regulatory factors necessary to transcribe the human CD4 gene.

scholarly journals Participation of the yeast activator Abf1 in meiosis-specific expression of the HOP1 gene.

1996 ◽  
Vol 16 (6) ◽  
pp. 2777-2786 ◽  
Author(s):  
V Gailus-Durner ◽  
J Xie ◽  
C Chintamaneni ◽  
A K Vershon
Keyword(s):  
Transcriptional Activation ◽  
Mutational Analysis ◽  
Consensus Sequence ◽  
Promoter Sequence ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Specific Expression ◽  
Autonomously Replicating Sequence

The meiosis-specific gene HOP1, which encodes a component of the synaptonemal complex, is controlled through two regulatory elements, UASH and URS1H. Sites similar to URS1H have been identified in the promoter region of virtually every early meiosis-specific gene, as well as in many promoters of nonmeiotic genes, and it has been shown that the proteins that bind to this site function to regulate meiotic and nonmeiotic transcription. Sites similar to the UASH site have been found in a number of meiotic and nonmeiotic genes as well. Since it has been shown that UASH functions as an activator site in vegetative haploid cells, it seemed likely that the factors binding to this site regulate both meiotic and nonmeiotic transcription. We purified the factor binding to the UASH element of the HOP1 promoter. Sequence analysis identified the protein as Abf1 (autonomously replicating sequence-binding factor 1), a multifunctional protein involved in DNA replication, silencing, and transcriptional regulation. We show by mutational analysis of the UASH site, that positions outside of the proposed UASH consensus sequence (TNTGN[A/T]GT) are required for DNA binding in vitro and transcriptional activation in vivo. A new UASH consensus sequence derived from this mutational analysis closely matches a consensus Abf1 binding site. We also show that an Abf1 site from a nonmeiotic gene can replace the function of the UASH site in the HOP1 promoter. Taken together, these results show that Abf1 functions to regulate meiotic gene expression.

scholarly journals The mechanism by which the human apolipoprotein B gene reducer operates involves blocking of transcriptional activation by hepatocyte nuclear factor 3.

1993 ◽  
Vol 13 (3) ◽  
pp. 1534-1546 ◽  
Author(s):  
B Paulweber ◽  
F Sandhofer ◽  
B Levy-Wilson
Keyword(s):  
Binding Site ◽  
Transcriptional Activation ◽  
Apolipoprotein B ◽  
Regulatory Protein ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Apo B ◽  
Human Apolipoprotein ◽  
Colon Carcinoma Cells ◽  
Mediator Protein

Previously, we showed that when a DNA fragment extending from -3067 to -2734 of the human apolipoprotein B (apo-B) gene is inserted immediately upstream of an apo-B promoter segment (-139 to +121), transcription from this promoter is reduced by about 10-fold in cultured colon carcinoma cells (CaCo-2) but not in cultured hepatoma cells (HepG2). We postulated that this reducer operates by a mechanism involving active repression of a transcriptional activator that binds to the segment from -111 to -88 of the apo-B promoter (B. Paulweber and B. Levy-Wilson, J. Biol. Chem. 266:24161-24168 1991). In the current study, the reducer element has been localized to a 24-bp sequence from -2801 to -2778 of the apo-B gene that contains a binding site for the negative regulatory protein ARP-1. Furthermore, we have demonstrated that the transcription factor hepatocyte nuclear factor 3 alpha (HNF-3 alpha) binds to the sequence 5'-TGTTTGCTTTTC-3' from -95 to -106 of the apo-B promoter, to stimulate transcription. Transcriptional activation by HNF-3 is repressed when the reducer sequence is inserted immediately upstream of the HNF-3 binding site, suggesting a mechanism by which the reducer-bound protein blocks the activation promoted by HNF-3. Data from cotransfection experiments in which ARP-1 is overexpressed in the absence of its binding site suggest that ARP-1 interacts either directly or via a mediator protein with proteins recognizing the HNF-3 site and that this interaction is sufficient to repress transcriptional activation by HNF-3. Because transcriptional activation by Sp1 is not affected by the reducer, it is unlikely that the reducer interacts directly with basic components of the transcriptional machinery.

scholarly journals An internal regulatory element controls troponin I gene expression.

1989 ◽  
Vol 9 (4) ◽  
pp. 1397-1405 ◽  
Author(s):  
K E Yutzey ◽  
R L Kline ◽  
S F Konieczny
Keyword(s):  
Transcriptional Activation ◽  
Troponin I ◽  
Protein Gene ◽  
Regulatory Element ◽  
Consensus Sequence ◽  
Regulatory Elements ◽  
Contractile Protein ◽  
Specific Expression ◽  
Cis Acting ◽  
Specific Expression Pattern

During skeletal myogenesis, approximately 20 contractile proteins and related gene products temporally accumulate as the cells fuse to form multinucleated muscle fibers. In most instances, the contractile protein genes are regulated transcriptionally, which suggests that a common molecular mechanism may coordinate the expression of this diverse and evolutionarily unrelated gene set. Recent studies have examined the muscle-specific cis-acting elements associated with numerous contractile protein genes. All of the identified regulatory elements are positioned in the 5'-flanking regions, usually within 1,500 base pairs of the transcription start site. Surprisingly, a DNA consensus sequence that is common to each contractile protein gene has not been identified. In contrast to the results of these earlier studies, we have found that the 5'-flanking region of the quail troponin I (TnI) gene is not sufficient to permit the normal myofiber transcriptional activation of the gene. Instead, the TnI gene utilizes a unique internal regulatory element that is responsible for the correct myofiber-specific expression pattern associated with the TnI gene. This is the first example in which a contractile protein gene has been shown to rely primarily on an internal regulatory element to elicit transcriptional activation during myogenesis. The diversity of regulatory elements associated with the contractile protein genes suggests that the temporal expression of the genes may involve individual cis-trans regulatory components specific for each gene.

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