scholarly journals The GC-box is critical for high level expression of the testis-specific Hsp70.2/Hst70 gene.

2007 ◽  
Vol 54 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Wiesława Widłak ◽  
Natalia Vydra ◽  
Volha Dudaladava ◽  
Dorota Scieglińska ◽  
Bolesław Winiarski ◽  
...  

The Hsp70.2/Hst70 gene, which belongs to the 70 kDa heat-shock protein (HSP) family, is expressed specifically in primary spermatocytes and spermatids. The regulatory elements required for a high level of testis-specific expression of the gene are placed between the two major transcription start sites T1 and T2 (approximately 350 and 115 bp upstream of the starting ATG codon). Here we have shown that sequences proximal to the exon1/intron splicing site in the 5' untranslated region of the Hsp70.2/Hst70 gene, which include a highly conserved element called box B, are required for efficient expression of the chloramphenicol acetyltransferase reporter gene in testes of transgenic mice. However, in spite of the drastically reduced overall activity, the stage-specific expression pattern of the transgene was preserved after removal of these sequences. We have also shown that GC-box located downstream of the box B (approximately 210 bp upstream of the starting ATG codon) is indispensable for efficient expression of the Hsp70.2/Hst70 gene promoter in spermatogenic cells. The GC-box specifically binds proteins present in nuclear extracts from testes (putatively Sp1-like factors). A change in the pattern of such GC-box-interacting factors corresponds to activation of the Hsp70.2/Hst70 gene, confirming the importance of this regulatory element.

1989 ◽  
Vol 9 (4) ◽  
pp. 1397-1405 ◽  
Author(s):  
K E Yutzey ◽  
R L Kline ◽  
S F Konieczny

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.


Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1345-1355 ◽  
Author(s):  
M. Xiang ◽  
S.Y. Lu ◽  
M. Musso ◽  
G. Karsenty ◽  
W.H. Klein

The LpS1 alpha and beta genes of Lytechinus pictus are activated at the late cleavage stage of embryogenesis, with LpS1 mRNAs accumulating only in lineages contributing to aboral ectoderm. We had shown previously that 762 bp of 5' flanking DNA from the LpS1 beta gene was sufficient for proper temporal and aboral ectoderm specific expression. In the present study, we identified a strong positive cis-regulatory element at −70 bp to −75 bp in the LpS1 beta promoter with the sequence (G)6 and a similar, more distal cis-element at −721 bp to −726 bp. The proximal ‘G-string’ element interacted with two nuclear factors, one specific to ectoderm and one to endoderm/mesoderm nuclear extracts, whereas the distal G-string element interacted only with the ectoderm factor. The ectoderm and endoderm/mesoderm G-string factors were distinct based on their migratory behavior in electrophoretic mobility shift assays, binding site specificities, salt optima and EDTA sensitivity. The proximal G-string element shared homology with a binding site for the mammalian transcription factor IF1, a protein that binds to negative cis-regulatory elements in the mouse alpha 1(I) and alpha 2(I) collagen gene promoters. Competition experiments using wild-type and mutant oligonucleotides indicated that the ectoderm G-string factor and IF1 have similar recognition sites. Partially purified IF1 specifically bound to an oligonucleotide containing the proximal G-string of LpS1 beta. From our results, we suggest that the ectoderm G-string factor, a member of the G-rich DNA-binding protein family, activates the LpS1 gene in aboral ectoderm cells by binding to the LpS1 promoter at the proximal G-string site.


1989 ◽  
Vol 9 (4) ◽  
pp. 1397-1405
Author(s):  
K E Yutzey ◽  
R L Kline ◽  
S F Konieczny

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.


Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3385-3393 ◽  
Author(s):  
KL Block ◽  
K Ravid ◽  
QH Phung ◽  
M Poncz

Abstract Glycoprotein (GP)IIb/IIIa, an integrin complex found on the surface of platelets, is a receptor for fibrinogen and other ligands, and is involved in platelet aggregation. Because GPIIb is specifically expressed in megakaryocytes, we have studied the 52-flanking region of the rat (r) GPIIb gene as a model of a megakaryocyte-specific gene. The studies presented here used a rat marrow expression system, which allows the study of primary cells undergoing terminal differentiation into megakaryocytes. The determination of megakaryocyte-specific expression of DNA constructs was possible by immunomagnetically separating megakaryocytes from total bone marrow cells. Transient expression constructs, containing varying lengths of the 52-flanking region from -39 to -912 bp, localized a regulatory element between -460 and -439 bp upstream of the transcriptional start site. This region contains a GATA consensus binding element between -457 and -454 (GATA454). Further constructs demonstrated that this GATA binding element was indeed essential for expression. A 25-bp substitution, covering the region -450 to -426 immediately downstream of the GATA454, demonstrated that this region was essential for full expression, which suggests that this region may interact with the GATA454 site in promoting high-level lineage-specific expression. To define regulatory elements between the GATA454 and the transcriptional start site further, we tested additional constructs derived from the original -912 construct; each of which contained the GATA454 but had different 50-bp deletions from -450 to the start site. Virtually all of these constructs continued to show high-level tissue-specific expression. The deleted -150 to -101 construct had twice the level of expression of the full-length wild-type construct; therefore, this region may contain a negative regulatory element. Comparison of our data with expression studies performed with the 52-region of the human GPIIb gene using HEL cells, a cell line with some megakaryocytic properties, demonstrates significant differences, which may reflect our use of primary rate bone marrow cells. In particular, our study points to the importance of the GATA454 for high levels of GPIIb expression in developing megakaryocytes.


Blood ◽  
1994 ◽  
Vol 84 (10) ◽  
pp. 3385-3393 ◽  
Author(s):  
KL Block ◽  
K Ravid ◽  
QH Phung ◽  
M Poncz

Glycoprotein (GP)IIb/IIIa, an integrin complex found on the surface of platelets, is a receptor for fibrinogen and other ligands, and is involved in platelet aggregation. Because GPIIb is specifically expressed in megakaryocytes, we have studied the 52-flanking region of the rat (r) GPIIb gene as a model of a megakaryocyte-specific gene. The studies presented here used a rat marrow expression system, which allows the study of primary cells undergoing terminal differentiation into megakaryocytes. The determination of megakaryocyte-specific expression of DNA constructs was possible by immunomagnetically separating megakaryocytes from total bone marrow cells. Transient expression constructs, containing varying lengths of the 52-flanking region from -39 to -912 bp, localized a regulatory element between -460 and -439 bp upstream of the transcriptional start site. This region contains a GATA consensus binding element between -457 and -454 (GATA454). Further constructs demonstrated that this GATA binding element was indeed essential for expression. A 25-bp substitution, covering the region -450 to -426 immediately downstream of the GATA454, demonstrated that this region was essential for full expression, which suggests that this region may interact with the GATA454 site in promoting high-level lineage-specific expression. To define regulatory elements between the GATA454 and the transcriptional start site further, we tested additional constructs derived from the original -912 construct; each of which contained the GATA454 but had different 50-bp deletions from -450 to the start site. Virtually all of these constructs continued to show high-level tissue-specific expression. The deleted -150 to -101 construct had twice the level of expression of the full-length wild-type construct; therefore, this region may contain a negative regulatory element. Comparison of our data with expression studies performed with the 52-region of the human GPIIb gene using HEL cells, a cell line with some megakaryocytic properties, demonstrates significant differences, which may reflect our use of primary rate bone marrow cells. In particular, our study points to the importance of the GATA454 for high levels of GPIIb expression in developing megakaryocytes.


Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4748-4756 ◽  
Author(s):  
Yoshiaki Okada ◽  
Ryohei Nagai ◽  
Takahiro Sato ◽  
Eri Matsuura ◽  
Takashi Minami ◽  
...  

AbstractPlatelet factor 4 (PF4) is expressed during megakaryocytic differentiation. We previously reported that GATA-1 and ETS-1 regulate the rat PF4 promoter and transactivate the PF4 gene. For the present study, we investigated the regulatory elements and their transcription factors responsible for the lineage-specific expression of the PF4 gene. The promoter activities of deletion constructs were evaluated, and a novel regulatory element termed TME (tandem repeat of MEIS1 binding element) (–219 to –182) was defined. Binding proteins to TME were strongly detected in HEL nuclear extracts by electrophoresis mobility shift assay (EMSA), and they were purified by DNA affinity chromatography. By performing Western blottings and supershift assays, the binding proteins were identified as homeodomain proteins, MEIS1, PBX1B, and PBX2. These factors are expressed in megakaryocytes differentiated from CD34+ cells in human cord blood. MEIS1 and PBXs bind to the TME as MEIS1/PBX complexes and activate the PF4 promoter. In nonmegakaryocytic HepG2 cells, GATA-1 and ETS-1 activate the PF4 promoter approximately 10-fold. Surprisingly, we found that additional expression of both MEIS1 and PBX2 multiplied this major activation another 2-fold. This activation was not observed when MEIS1 binding sites in the TME were disrupted. Furthermore, inhibition of the binding of endogenous MEIS1/PBX complexes to the TME decreased the promoter activity by almost one half, in megakaryocytic HEL cells. Thus, these studies demonstrate that the homeodomain proteins, MEIS1, PBX1B, and PBX2, play an important role in megakaryocytic gene expression.


Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 881-894 ◽  
Author(s):  
Y.I. Yeom ◽  
G. Fuhrmann ◽  
C.E. Ovitt ◽  
A. Brehm ◽  
K. Ohbo ◽  
...  

The totipotent stem cells of the pregastrulation mouse embryo which give rise to all embryonic somatic tissues and germ cells express Oct-4. The expression is downregulated during gastrulation and is thereafter only maintained in the germline lineage. Oct-4/lacZ transgenes were used to determine how this pattern of expression was achieved, and resulted in the identification of two separate regulatory elements. The distal element drives Oct-4 expression in preimplantation embryos, in migratory and postmigratory primordial germ cells but is inactive in cells of the epiblast. In cell lines this element is specifically active in embryonic stem and embryonic germ cells. The proximal element directs the epiblast-specific expression pattern, including downregulation during gastrulation; in cell lines its activity is restricted to epiblast-derived cells. Thus, Oct-4 expression in the germline is regulated separately from epiblast expression. This provides the first marker for the identification of totipotent cells in the embryo, and suggests that expression of Oct-4 in the totipotent cycle is dependent on a set of factors unique to the germline.


Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  

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.


1992 ◽  
Vol 286 (1) ◽  
pp. 179-185 ◽  
Author(s):  
C P Simkevich ◽  
J P Thompson ◽  
H Poppleton ◽  
R Raghow

The transcriptional activity of plasmid pCOL-KT, in which human pro alpha 1 (I) collagen gene upstream sequences up to -804 and most of the first intron (+474 to +1440) drive expression of the chloramphenicol acetyltransferase (CAT) gene [Thompson, Simkevich, Holness, Kang & Raghow (1991) J. Biol. Chem. 266, 2549-2556], was tested in a number of mesenchymal and non-mesenchymal cells. We observed that pCOL-KT was readily expressed in fibroblasts of human (IMR-90 and HFL-1), murine (NIH 3T3) and avian (SL-29) origin and in a human rhabdomyosarcoma cell line (A204), but failed to be expressed in human erythroleukaemia (K562) and rat pheochromocytoma (PC12) cells, indicating that the regulatory elements required for appropriate tissue-specific expression of the human pro alpha 1 (I) collagen gene were present in pCOL-KT. To delineate the nature of cis-acting sequences which determine the tissue specificity of pro alpha 1 (I) collagen gene expression, functional consequences of deletions in the promoter and first intron of pCOL-KT were tested in various cell types by transient expression assays. Cis elements in the promoter-proximal and intronic sequences displayed either a positive or a negative influence depending on the cell type. Thus deletion of fragments using EcoRV (nt -625 to -442 deleted), XbaI (-804 to -331) or SstII (+670 to +1440) resulted in 2-10-fold decreased expression in A204 and HFL-1 cells. The negative influences of deletions in the promoter-proximal sequences was apparently considerably relieved by deleting sequences in the first intron, and the constructs containing the EcoRV/SstII or XbaI/SstII double deletions were expressed to a much greater extent than either of the single deletion constructs. In contrast, the XbaI* deletion (nt -804 to -609), either alone or in combination with the intronic deletion, resulted in very high expression in all cells regardless of their collagen phenotype; the XbaI*/(-SstII) construct, which contained the intronic SstII fragment (+670 to +1440) in the reverse orientation, was not expressed in either mesenchymal or nonmesenchymal cells. Based on these results, we conclude that orientation-dependent interactions between negatively acting 5′-upstream sequences and the first intron determine the mesenchymal cell specificity of human pro alpha 1 (I) collagen gene transcription.


1990 ◽  
Vol 10 (12) ◽  
pp. 6204-6215
Author(s):  
A Pierani ◽  
A Heguy ◽  
H Fujii ◽  
R G Roeder

Several distinct octamer-binding transcription factors (OTFs) interact with the sequence ATTTGCAT (the octamer motif), which acts as a transcription regulatory element for a variety of differentially controlled genes. The ubiquitous OTF-1 plays a role in expression of the cell cycle-regulated histone H2b gene as well as several other genes, while the tissue-specific OTF-2 has been implicated in the tissue-specific expression of immunoglobulin genes. In an attempt to understand the apparent transcriptional selectivity of these factors, we have investigated the physical and functional characteristics of OTF-1 purified from HeLa cells and both OTF-1 and OTF-2 purified from B cells. High-resolution footprinting and mobility shift-competition assays indicated that these factors were virtually indistinguishable in binding affinities and DNA-protein contacts on either the H2b or an immunoglobulin light-chain (kappa) promoter. In addition, each of the purified factors showed an equivalent intrinsic capacity to activate transcription from either immunoglobulin promoters (kappa and heavy chain) or the H2b promoter in OTF-depleted HeLa and B-cell extracts. However, with OTF-depleted HeLa extracts, neither factor could restore immunoglobulin gene transcription to the relatively high level observed in unfractionated B-cell extracts. Restoration of full immunoglobulin gene activity appears to require an additional B-cell regulatory component which interacts with the OTFs. The additional B-cell factor could act either by facilitating interaction of OTF activation domains with components of the general transcriptional machinery or by contributing a novel activation domain.


Sign in / Sign up

Export Citation Format

Share Document