1
|
Regulation of neural stem cell differentiation by transcription factors HNF4-1 and MAZ-1. Mol Neurobiol 2012; 47:228-40. [PMID: 22944911 DOI: 10.1007/s12035-012-8335-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/16/2012] [Indexed: 10/27/2022]
Abstract
Neural stem cells (NSCs) are promising candidates for a variety of neurological diseases due to their ability to differentiate into neurons, astrocytes, and oligodentrocytes. During this process, Rho GTPases are heavily involved in neuritogenesis, axon formation and dendritic development, due to their effects on the cytoskeleton through downstream effectors. The activities of Rho GTPases are controlled by Rho-GDP dissociation inhibitors (Rho-GDIs). As shown in our previous study, these are also involved in the differentiation of NSCs; however, little is known about the underlying regulatory mechanism. Here, we describe how the transcription factors hepatic nuclear factor (HNF4-1) and myc-associated zinc finger protein (MAZ-1) regulate the expression of Rho-GDIγ in the stimulation of NSC differentiation. Using a transfection of cis-element double-stranded oligodeoxynucleotides (ODNs) strategy, referred to as "decoy" ODNs, we examined the effects of HNF4-1 and MAZ-1 on NSC differentiation in the NSC line C17.2. Our results show that HNF4-1 and MAZ-1 decoy ODNs significantly knock down Rho-GDIγ gene transcription, leading to NSC differentiation towards neurons. We observed that HNF4-1 and MAZ-1 decoy ODNs are able enter to the cell nucleolus and specifically bind to their target transcription factors. Furthermore, the expression of Rho-GDIγ-mediated genes was identified, suggesting that the regulatory mechanism for the differentiation of NSCs is triggered by the transcription factors MAZ-1 and HNF4-1. These findings indicate that HNF4-1 and MAZ-1 regulate the expression of Rho-GDIγ and contribute to the differentiation of NSCs. Our findings provide a new perspective within regulatory mechanism research during differentiation of NSCs, especially the clinical application of transcription factor decoys in vivo, suggesting potential therapeutic strategies for neurodegenerative disease.
Collapse
|
2
|
Szaro BG, Strong MJ. Regulation of Cytoskeletal Composition in Neurons: Transcriptional and Post-transcriptional Control in Development, Regeneration, and Disease. ADVANCES IN NEUROBIOLOGY 2011. [DOI: 10.1007/978-1-4419-6787-9_24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
3
|
Ugai H, Li HO, Komatsu M, Tsutsui H, Song J, Shiga T, Fearon E, Murata T, Yokoyama KK. Interaction of Myc-associated zinc finger protein with DCC, the product of a tumor-suppressor gene, during the neural differentiation of P19 EC cells. Biochem Biophys Res Commun 2001; 286:1087-97. [PMID: 11527412 DOI: 10.1006/bbrc.2001.5469] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Expression of the DCC (deleted in colorectal cancer) protein is strongly induced during the neural differentiation of mouse P19 embryonal carcinoma (EC) cells that occurs when these cells are treated with retinoic acid (RA). Myc-associated zinc finger protein (MAZ) is a DNA-binding protein that is widely expressed and functions in human, mouse and hamster cells as an activator, an initiator or a terminator of transcription. However, the biological functions of MAZ remain elusive. We report here that MAZ associates with the cytoplasmic domain of the DCC protein in vivo and in vitro. Yeast two-hybrid assays confirmed this association. An immunofluorescence study demonstrated that DCC protein is expressed at elevated levels in neuron-like P19 EC cells, in particular in axons, in which the MAZ protein is also expressed. We found that MAZ was translocated from the nucleus to the cytoplasm during the RA-induced terminal differentiation of P19 EC cells with resultant loss of the ability of MAZ to bind to the ME1a1 site of the c-myc promoter. Taken together, our observations imply that the DCC protein might play a critical role as a signaling molecule in the regulation of the transcriptional activity of MAZ during the neural differentiation of P19 EC cells.
Collapse
MESH Headings
- Active Transport, Cell Nucleus
- Amino Acid Sequence
- Animals
- Binding Sites
- Blotting, Northern
- Blotting, Western
- Cell Adhesion Molecules/metabolism
- Cell Differentiation
- Cell Line
- Cell Nucleus/metabolism
- Cytoplasm/metabolism
- DCC Receptor
- DNA-Binding Proteins
- Genes, myc/genetics
- Humans
- Immunohistochemistry
- Microscopy, Fluorescence
- Models, Biological
- Molecular Sequence Data
- Neurons/metabolism
- Plasmids/metabolism
- Precipitin Tests
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- RNA/metabolism
- RNA, Messenger/metabolism
- Receptors, Cell Surface
- Recombinant Fusion Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Homology, Amino Acid
- Signal Transduction
- Time Factors
- Transcription Factors/metabolism
- Transcription, Genetic
- Transfection
- Tretinoin/metabolism
- Tumor Suppressor Proteins
- Two-Hybrid System Techniques
- Xenopus
- Zinc Fingers
Collapse
Affiliation(s)
- H Ugai
- Gene Engineering Division, Bioresource Center, Tsukuba Institute, RIKEN (The Institute of Physical and Chemical Research), 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Roosa JR, Gervasi C, Szaro BG. Structure, biological activity of the upstream regulatory sequence, and conserved domains of a middle molecular mass neurofilament gene of Xenopus laevis. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 82:35-51. [PMID: 11042356 DOI: 10.1016/s0169-328x(00)00180-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
During development, the molecular compositions of neurofilaments (NFs) undergo progressive modifications that correlate with successive stages of axonal outgrowth. Because NFs are the most abundant component of the axonal cytoskeleton, understanding how these modifications are regulated is essential for knowing how axons control their structural properties during growth. In vertebrates ranging from lamprey to mammal, orthologs of the middle molecular mass NF protein (NF-M) share similar patterns of expression during axonal outgrowth, which suggests that these NF-M genes may share conserved regulatory elements. These elements might be identified by comparing the sequences and activities of regulatory domains among the vertebrate NF-M genes. The frog, Xenopus laevis, is a good choice for such studies, because its early neural development can be observed readily and because transgenic embryos can be made easily. To begin such studies, we isolated genomic clones of Xenopus NF-M(2), tested the activity of its upstream regulatory sequence (URS) in transgenic embryos, and then compared sequences of regulatory regions among vertebrate NF-M genes to search for conserved elements. Studies with reporter genes in transgenic embryos found that the 1. 5 kb URS lacked the elements sufficient for neuron-specific gene expression but identified conserved regions with basal regulatory activity. These studies further demonstrated that the NF-M 1.5 kb URS was highly susceptible to positional effects, a property that may be relevant to the highly variant, tissue-specific expression that is seen among members of the intermediate filament gene family. Non-coding regions of vertebrate NF-M genes contained several conserved elements. The region of highest conservation fell within the 3' untranslated region, a region that has been shown to regulate expression of another NF gene, NF-L. Transgenic Xenopus may thus prove useful for testing further the activity of conserved elements during axonal development and regeneration.
Collapse
Affiliation(s)
- J R Roosa
- Neurobiology Research Center and The Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | | | | |
Collapse
|
5
|
Ekblom J, Garpenstrand H, Damberg M, Chen K, Shih JC, Oreland L. Transcription factor binding to the core promoter of the human monoamine oxidase B gene in the cerebral cortex and in blood cells. Neurosci Lett 1998; 258:101-4. [PMID: 9875537 DOI: 10.1016/s0304-3940(98)00864-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many studies show that monoamine oxidase B in blood cells is a biological marker for personality characteristics such as sensation seeking. The mechanism underlying this association is so far not explored. In the present study we have performed electrophoretic mobility-shift assays to investigate the pattern of protein binding to a 150 bp fragment of the proximal 5'-flanking region of the human monoamine oxidase B gene. We compared the pattern using nuclear extracts from human brain and lymphocytes. Interestingly, a correlation was observed between monoamine oxidase B enzyme activity in blood cells (platelets) and the binding pattern of two uncharacterized transcription factors. These data are well in line with the long-standing notion that interindividual differences in platelet monoamine oxidase may represent differences in expression of the enzyme rather than genotypic variation.
Collapse
Affiliation(s)
- J Ekblom
- Department of Neuroscience, Uppsala University, Sweden
| | | | | | | | | | | |
Collapse
|
6
|
Holtmaat AJ, Oestreicher AB, Gispen WH, Verhaagen J. Manipulation of gene expression in the mammalian nervous system: application in the study of neurite outgrowth and neuroregeneration-related proteins. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1998; 26:43-71. [PMID: 9600624 DOI: 10.1016/s0165-0173(97)00044-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A fundamental issue in neurobiology entails the study of the formation of neuronal connections and their potential to regenerate following injury. In recent years, an expanding number of gene families has been identified involved in different aspects of neurite outgrowth and regeneration. These include neurotrophic factors, cell-adhesion molecules, growth-associated proteins, cytoskeletal proteins and chemorepulsive proteins. Genetic manipulation technology (transgenic mice, knockout mice, viral vectors and antisense oligonucleotides) has been instrumental in defining the function of these neurite outgrowth-related proteins. The aim of this paper is to provide an overview of the above-mentioned four approaches to manipulate gene expression in vivo and to discuss the progress that has been made using this technology in helping to understand the molecular mechanisms that regulate neurite outgrowth. We will show that work with transgenic mice and knockout mice has contributed significantly to the dissection of the function of several proteins with a key role in neurite outgrowth and neuronal survival. Recently developed viral vectors for gene transfer in postmitotic neurons have opened up new avenues to analyze the function of a protein following local expression in naive adult rodents. The initial results with viral vector-based gene transfer provide a conceptual framework for further studies on genetic therapy of neuroregeneration and neurodegenerative diseases.
Collapse
Affiliation(s)
- A J Holtmaat
- Graduate School of Neurosciences Amsterdam, Netherlands Institute for Brain Research
| | | | | | | |
Collapse
|
7
|
Schwartz ML, Hua Y, Schlaepfer WW. In vitro activation of the mouse mid-sized neurofilament gene by an NF-1-like transcription factor. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 48:305-14. [PMID: 9332728 DOI: 10.1016/s0169-328x(97)00110-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In vitro transcription using nuclear extracts from rat brain and liver were used to assess the tissue-specific and functional elements of the mouse neurofilament mid-sized gene promoter (pNF-M). Deletion from -2.7 to -103 (relative to the start site of transcription) resulted in a small increase (2-fold) in the activity of the NF-M promoter in both extracts. Promoter strength was slightly higher in brain vs. liver extracts. Deletion to -49 resulted in a 10-fold loss of promoter activity in brain extracts and 6-fold drop in liver. Transcription in both extracts was TATA box-dependent. The region between -65 and -40 was shown to contain sequences responsible for high-level NF-M promoter activity in brain and liver extracts. Within this region are Sp1 and NF-1-like binding sites. Mutation of the NF-1-like site (-53/-39) caused a large drop in the activity of the NF-M promoter while mutation of the Sp1 site (-64/-57) possibly slightly diminished promoter activity in brain and liver extracts. Both the Sp1 and NF-1-like sites were shown by gel shift competition and supershift assays to be able to bind their respective factors. We conclude that the basic mouse NF-M promoter is a promiscuous promoter whose activity is modulated by a NF-1-like transcription factor. The lack of tissue specificity in an in vitro system strongly suggests an important role for chromatin structure in the regulation of the mouse NF-M promoter.
Collapse
Affiliation(s)
- M L Schwartz
- Division of Neuropathology, University of Pennsylvania Medical School, Philadelphia 19104, USA.
| | | | | |
Collapse
|
8
|
Nerve growth factor induces transcription of the p21 WAF1/CIP1 and cyclin D1 genes in PC12 cells by activating the Sp1 transcription factor. J Neurosci 1997. [PMID: 9236224 DOI: 10.1523/jneurosci.17-16-06122.1997] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The PC12 pheochromocytoma cell line responds to nerve growth factor (NGF) by gradually exiting from the cell cycle and differentiating to a sympathetic neuronal phenotype. We have shown previously () that NGF induces the expression of the p21 WAF1/CIP1/Sdi1 (p21) cyclin-dependent kinase (Cdk) inhibitor protein and the G1 phase cyclin, cyclin D1. In this report, we show that induction is at the level of transcription and that the DNA elements in both promoters that are required for NGF-specific induction are clusters of binding sites for the Sp1 transcription factor. NGF also induced a synthetic promoter with repeated Sp1 sites linked to a core promoter, and a plasmid regulated by a chimeric transactivator in which the Gal4 DNA binding domain is fused to the Sp1 transactivation domain, indicating that this transactivation domain is regulated by NGF. Epidermal growth factor, which is a weak mitogen for PC12, failed to induce any of these promoter constructs. We consider a model in which the PC12 cell cycle is arrested as p21 accumulates and attains inhibitory levels relative to Cdk/cyclin complexes. Sustained activation of p21 expression is proposed to be a distinguishing feature of the activity of NGF that contributes to PC12 growth arrest during differentiation
Collapse
|
9
|
Kure R, Brown IR. Developmental analysis of factors binding to the mouse 68-kDa neurofilament promoter. Neurochem Res 1997; 22:555-62. [PMID: 9131633 DOI: 10.1023/a:1022461817786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Whole tissue extracts prepared from mouse brain regions at various postnatal ages were characterized for binding of factors to the DNase I hypersensitive site (HSSI) which is located closest to the transcription start site of the 68-kDa mouse neurofilament gene (NF-L). Gel mobility shift assays detected changes in factor binding during postnatal development of the neocortex. Competition experiments suggested that one of the complexes resulted from factor binding to a 9 bp sequence found in both the light and medium neurofilament promoter regions (NF-L/M). Gel mobility shifts performed with an oligonucleotide probe containing the NF-L/M sequence detected two brain-specific DNA-protein complexes, and a third complex in both brain and liver. During cerebellar and neocortical development, one of the NF-L/M complexes was most intense at postnatal day 10 when transcription of the NF-L gene is upregulated.
Collapse
Affiliation(s)
- R Kure
- Department of Zoology, University of Toronto, West Hill Ontario, Canada
| | | |
Collapse
|
10
|
Abstract
RN46A cells, a conditionally immortalized neuronal cell line derived from E12 rat medullary raphe nucleus, upregulate low M(r) (68 kDa, neurofilament [NF]-L) and medium M(r) (160 kDa, NF-M) neurofilament protein expression upon activation of protein kinase A (PKA). To examine possible transcriptional regulation of neurofilament protein expression by PKA, two cell lines were used; RN46A cells and C alpha EV6 cells, a cell line derived from RN46A cells that stably expresses the catalytic subunit of PKA under the control of the metallothionein promoter. Treatment of RN46A cells with dbcAMP resulted in an increase in the steady-state levels of both NF-L and NF-M, but not high M(r) (200 kDa, NF-H) neurofilament mRNA. These increases were both time and dose dependent and were sensitive to treatment with the protein synthesis inhibitor cycloheximide. In C alpha EV6 cells, activation of PKA by 80 microM ZnSO4 upregulated the expression of C alpha mRNA with maximal levels reached 8 hr post-treatment and maintained at 24 hr. Reporter gene assays in C alpha EV6 cells following transfection with increasing lengths of the NF-L promoter demonstrated that both a putative Sp1-like and a cAMP response (CRE), but not a NGFI-A, element were likely involved in PKA-dependent activation of the NF-L promoter. Electrophoretic mobility shift assays confirmed these results but showed that the nuclear proteins induced by PKA which bound to the NF-L promoter Sp1-like sequence were not Sp1. Collectively, these data suggest that constitutively expressed Sp1 may be involved in basal NF-L promoter activity, and newly synthesized, PKA-dependent nuclear proteins may synergistically activate the rat NF-L promoter.
Collapse
Affiliation(s)
- L A White
- Miami Project, University of Miami School of Medicine, Florida, USA
| | | | | | | |
Collapse
|
11
|
Kure R, Ivanov TR, Brown IR. Characterization of DNase I hypersensitive sites in the mouse 68-kDa neurofilament gene. Neurochem Res 1996; 21:713-22. [PMID: 8829145 DOI: 10.1007/bf02527730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Four brain-specific DNase I hypersensitive sites (HSS) have previously been identified flanking the mouse 68-kDa neurofilament gene within a 1.7 kb upstream sequence which confers neuronal specificity of expression of this gene in transgenic mice. Previously several DNA-binding factors were detected at the HSS closest to the transcription start site (HSS1). However, no major brain-specific factors were identified, suggesting a possible role for the three remaining HSS in conferring tissue-specificity to the NF-L gene. Sequence analysis of the NF-L promoter region demonstrated the presence of an extensive CT repeat and several potential binding sites which are also found in other neurofilament promoters. Gel mobility shift assays revealed a similar but not identical banding pattern with brain and liver nuclear extracts at HSS2, and HSS3, however the banding pattern for HSS4 was predominantly brain-specific. DNase I footprinting revealed several factors binding to the upstream HSS regions in brain and liver nuclear extracts. These include a CCAAT box at HSS2, a novel brain-specific footprint near an adenovirus promoter element E2aE-C beta and a single liver-specific footprint associated with an POU/octamer binding site at HSS4. The presence of brain-specific gel shift bands and tissue-specific footprints associated with HSS4, suggest that this region may play an important role in the regulation of the NF-L gene.
Collapse
Affiliation(s)
- R Kure
- Department of Zoology, University of Toronto, West Hill, Ontario, Canada
| | | | | |
Collapse
|
12
|
Chan SO, Chiu FC. The 66-kDa neurofilament protein (NF-66): sequence analysis and evolution. Neurochem Res 1996; 21:449-55. [PMID: 8734438 DOI: 10.1007/bf02527709] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A 2.5 kb cDNA clone encoding the mouse 66 kd neurofilament protein (NF-66) was isolated and sequenced. The deduced protein sequence contains 501 amino acid residues. Comparison of the mouse, rat and human NF-66 indicated > 90% homology in protein sequence and 85% homology in coding nucleotide sequence. A high degree of homology was observed between NF-66 and other intermediate filament proteins especially in the alpha-helical domain. Zooblot analyses suggested that the putative ancestral gene for vimentin and NF-66 was detectable in the avian. By comparison, the ancestral sequence for GFAP appeared after that for vimentin.
Collapse
Affiliation(s)
- S O Chan
- Saul Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | |
Collapse
|
13
|
Cibelli G, Schoch S, Pajunk H, Brand IA, Thiel G. A (G+C)-rich motif in the aldolase C promoter functions as a constitutive transcriptional enhancer element. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 237:311-7. [PMID: 8620889 DOI: 10.1111/j.1432-1033.1996.0311n.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The enzyme fructose-1,6-bisphosphate aldolase consists of three isozymes that are expressed in a tissue-specific manner. Using antibodies against aldolase B and C, it is shown that aldolase C is expressed in virtually all neuronal cell lines derived from the central and peripheral nervous system. Recently, experiments with transgenic mice indicated that a (G+C)-rich region of the aldolase C promoter might function as a neuron-specific control element of the rat aldolase C gene [Thomas, M., Makeh, I., Briand, P., Kahn, A. & Skala, H. (1993) Eur. J. Biochem. 218, 143-151). To functionally analyse this element, a plasmid consisting of four copies of this (G+C)-rich sequence, a TATA box, and the rabbit beta-globin gene as reporter was constructed. This plasmid was transfected into neuronal and nonneuronal cell lines and transcription was monitored by RNase protection mapping of the beta-globin mRNA. It is shown that the (G+C)-rich element of the aldolase C promoter directs transcription in neuronal as well as in nonneuronal cells. In contrast, the synapsin I promoter, used as a control for neuron-specific gene expression, directed transcription only in neuronal cells. In gel-retardation assays, two major DNA-protein complexes were detected with the (G+C)-rich element of the aldolase C promoter used as a DNA probe and nuclear extracts from brain and liver as a source for DNA-binding proteins. These DNA-proteins interactions could be impaired by a DNA probe that contained an Sp1-binding site, indicating that Sp1 or an Sp1-related factor binds to the aldolase C promoter (G+C)-rich element. This was confirmed by supershift analysis with antibodies specific for Sp1. The zinc finger transcription factor zif268/egr-1, also known to recognize a (G+C)-rich consensus site, did not, however, bind to the (G+C)-rich motif of the aldolase C promoter, nor could it stimulate transcription in transactivation assays from this control region. From these data, we conclude that the (G+C)-rich element of the aldolase C promoter functions as a constitutive transcriptional response element mediated by Sp1 and Sp1-related transcription factors.
Collapse
Affiliation(s)
- G Cibelli
- Institute for Genetics, University of Cologne, Germany
| | | | | | | | | |
Collapse
|
14
|
Twyman RM, Jones EA. The regulation of neuron-specific gene expression in the mammalian nervous system. J Neurogenet 1995; 10:67-101. [PMID: 8592273 DOI: 10.3109/01677069509083457] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- R M Twyman
- Department of Biological Sciences, University of Warwick, Coventry, England
| | | |
Collapse
|
15
|
Reeben M, Neuman T, Palgi J, Palm K, Paalme V, Saarma M. Characterization of the rat light neurofilament (NF-L) gene promoter and identification of NGF and cAMP responsive regions. J Neurosci Res 1995; 40:177-88. [PMID: 7745611 DOI: 10.1002/jnr.490400206] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have isolated a genomic DNA clone covering the coding and 14 kb upstream region of the rat light neurofilament (NF-L) gene and sequenced 2.3 kb of its promoter. DNase I hypersensitive sites have been mapped in PC12 cells. For functional analysis of the NF-L promoter, constructs carrying 38, 97, 407, 564, 650, 1,099, 1,660, 2,003 base pairs (bp) upstream region in front of the chloramphenicol acetyltransferase (CAT) reporter gene were tested for their capability to direct CAT expression after transient transfection into various cell lines. Similar CAT activities were recorded both in rat pheochromocytoma (PC12) and mouse neuroblastoma N115 cells and also in several nonneural cell lines (HeLa, C127, NIH 3T3). Regions responsible for the basic promoter activity were located between -407 and +75 bp from the transcription initiation site. The NGF-responsive element was located between -38 and +75 bp, and sequence -97 to -38 was found to contain a functional cAMP-responsive element. In PC12 cells in which nerve growth factor (NGF) induces neurite outgrowth and NF-L transcription, NF-L promoter-driven CAT expression was stimulated up to 12-fold within three days of NGF treatment, whereas epidermal growth factor (EGF) had no effect. Rat NF-L promoter contained Sp1, AP-2 and CGCCCCCGC elements. In PC12 cells, NGF transiently induced the binding of transcription factors to the deoxyoligonucleotide probes containing the binding sites of these elements. The role of these factors in NF-L gene transcriptional induction by NGF in PC12 cells is discussed.
Collapse
Affiliation(s)
- M Reeben
- Laboratory of Molecular Genetics, Estonian Academy of Sciences, Tallinn
| | | | | | | | | | | |
Collapse
|
16
|
BSF1, a novel brain-specific DNA-binding protein recognizing a tandemly repeated purine DNA element in the GABAA receptor delta subunit gene. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36601-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
17
|
Schwartz M, Katagi C, Bruce J, Schlaepfer W. Brain-specific enhancement of the mouse neurofilament heavy gene promoter in vitro. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36852-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
18
|
Eyer J, Peterson A. Neurofilament-deficient axons and perikaryal aggregates in viable transgenic mice expressing a neurofilament-beta-galactosidase fusion protein. Neuron 1994; 12:389-405. [PMID: 8110465 DOI: 10.1016/0896-6273(94)90280-1] [Citation(s) in RCA: 220] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Interactions between neurofilament side arms may modulate axon caliber. To investigate this hypothesis, we derived transgenic mice expressing a fusion protein in which the carboxyl terminus of the high molecular weight neurofilament protein (NFH) was replaced by beta-galactosidase. The transgene, regulated by NFH sequences, was expressed in projection neurons. However, the fusion protein remained in perikarya precipitating large filamentous aggregates. Axons were not invested with neurofilaments and developed only small calibers. Perikaryal aggregates, with similar structural features, are associated with neurodegenerative diseases, but these mice showed few ill effects and their neurons rarely degenerated. We conclude that an organized neurofilament cytoskeleton is required by axons to achieve large calibers but is not essential for neuronal function or extended survival.
Collapse
Affiliation(s)
- J Eyer
- Department of Neurology and Neurosurgery, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada
| | | |
Collapse
|
19
|
Abstract
In the past few years, several neuronal intermediate filament proteins have been characterized. While ongoing investigations have continued to shed light on their developmental expression, the importance of different domains of the proteins for assembly, the elements in their genes necessary for tissue-specific expression, and the role of phosphorylation of neurofilaments, the function(s) of these structures remain a matter of speculation.
Collapse
Affiliation(s)
- R K Liem
- Department of Pathology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| |
Collapse
|
20
|
Elder GA, Liang Z, Li C, Lazzarini RA. Targeting of Sp1 to a non-Sp1 site in the human neurofilament (H) promoter via an intermediary DNA-binding protein. Nucleic Acids Res 1992; 20:6281-5. [PMID: 1475189 PMCID: PMC334517 DOI: 10.1093/nar/20.23.6281] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The human neurofilament (H) promoter contains multiple binding sites for nuclear proteins including a Proximal (Prox) site centered around the sequence GGTTGGACC and an adjacent pyrimidine (Pyr) tract site centered around the sequence CCCTCCTCCCC. Surprisingly binding to a probe containing the Prox/Pyr region of the NF(H) promoter was competed in gel shifts by an oligonucleotide containing only an Sp1 binding site (GGGGCGGGG). Supershift assays with a polyclonal anti-Sp1 antisera confirmed that Sp1 was part of the complex formed with the Prox/Pyr probe. However neither bacterially expressed Sp1 516C or vaccinia virus expressed full-length Sp1 778C bound to the Prox or Pyr sequences in DNase I footprints or gel shift assays. Gel shift competitions and supershift assays with probes containing either Prox or Pyr tract sites alone demonstrated targeting of Sp1 to the Prox binding site and identified a non-Sp1 containing complex which contains a Prox binding protein. Adding exogenous Sp1 to a HeLa nuclear extract enhanced the Sp1-containing complex but had no effect on the Prox complex. These studies show that Sp1 can be targeted to a non-Sp1 site in the human NF(H) promoter through protein/protein interactions with a distinct sequence specific DNA-binding protein.
Collapse
Affiliation(s)
- G A Elder
- Brookdale Center for Molecular Biology, Mount Sinai School of Medicine, New York, NY 10029
| | | | | | | |
Collapse
|
21
|
Elder GA, Liang Z, Snyder SE, Lazzarini RA. Multiple nuclear factors interact with the promoter of the human neurofilament M gene. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1992; 15:99-107. [PMID: 1331673 DOI: 10.1016/0169-328x(92)90156-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to identify potential regulatory elements of the human mid-sized (M) neurofilament (NF) gene we preformed DNase I footprinting, gel mobility shift assays and methylation interference studies with probes from the NF(M) immediate 5' flanking region. These studies identified multiple sites for DNA-binding proteins including four Sp1 sites, and single sites each for members of the NF-1 and AP-1 families of DNA binding proteins. In addition a binding site within a pyrimidine tract likely binds a novel DNA-binding protein which also interacts with the human NF(H) gene promoter. Factors that bind to these sites are found in both neural and non-neural cells suggesting that the NF(M) promoter may not contain tissue specific regulatory signals. In transient assays, addition of these binding sites to an NF(M) minimal promoter containing only a TATA box lead to a greater than 40-fold activation of transcription over background. Progressive 5' deletions reduced expression in a step wise manner suggesting that all the factors likely act synergistically as positive regulators of transcription.
Collapse
Affiliation(s)
- G A Elder
- Brookdale Center for Molecular Biology, Mount Sinai School of Medicine, New York, NY 10029
| | | | | | | |
Collapse
|