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Seneviratne D, Ma J, Tan X, Kwon YK, Muhammad E, Melhem M, DeFrances MC, Zarnegar R. Genomic instability causes HGF gene activation in colon cancer cells, promoting their resistance to necroptosis. Gastroenterology 2015; 148:181-191.e17. [PMID: 25244939 PMCID: PMC4274190 DOI: 10.1053/j.gastro.2014.09.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 08/19/2014] [Accepted: 09/14/2014] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Genomic instability promotes colon carcinogenesis by inducing genetic mutations, but not all genes affected by this process have been identified. We investigated whether genomic instability in human colorectal cancer (CRC) cells produces mutations in the hepatocyte growth factor (HGF) gene. METHODS We genotyped human colon tumor tissues and adjacent nontumor tissues collected from 78 patients University of Pittsburgh Health Sciences and Veterans Hospital, along with 40 human CRC and adjacent nontumor tissues in a commercial microarray. We used cellular, biochemical, and molecular biological techniques to investigate the factors that alter HGF signaling in colon cancer cells and its effects on cell proliferation and survival. RESULTS All tested human CRC tissues and cell lines that had microsatellite instability contained truncations in the regulatory deoxyadenosine tract element (DATE) of the HGF gene promoter. The DATE was unstable in 14% (11 of 78) of CRC samples; DATE truncation was also polymorphic and detected in 18% (13 of 78) of CRC tissues without microsatellite instability. In CRC cell lines, truncation of DATE activated expression of HGF, resulting in its autocrine signaling via MET. This promoted cell proliferation and resistance to necroptosis. HGF signaling via MET reduced levels of the receptor-interacting serine-threonine kinase 1, a mediator of necroptosis, in CRC cells. High levels of HGF protein in tumor tissues correlated with lower levels of receptor-interacting serine-threonine kinase 1 and shorter survival times of patients. CONCLUSIONS Thirty-one percent of CRC samples contain alterations in the DATE of the HGF promoter. Disruption of the DATE increased HGF signaling via MET and reduced levels of receptor-interacting serine-threonine kinase 1 and CRC cell necroptosis. DATE alteration might be used as a prognostic factor or to select patients for therapies that target HGF-MET signaling.
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Affiliation(s)
| | | | | | | | | | | | | | - Reza Zarnegar
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
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2
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Chiba S, Tsuchiya N, Horikawa Y, Narita S, Inoue T, Akihama S, Saito M, Numakura K, Tsuruta H, Huang M, Satoh S, Habuchi T. Functional mononucleotide repeat polymorphism in the promoter region of HGF is associated with risk and malignant aggressiveness of bladder cancer. Int J Oncol 2013; 44:678-84. [PMID: 24366484 DOI: 10.3892/ijo.2013.2221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 11/18/2013] [Indexed: 11/05/2022] Open
Abstract
Increased expression of hepatocyte growth factor (HGF) has been shown to be associated with aggressiveness in several types of cancer. Shorter variants of deoxyadenosine tract element (DATE) located in the HGF promoter region have been reported to enhance the expression of HGF. In this study, we investigated the role of HGF DATE variants in bladder cancer risk, HGF expression and clinicopathological features. The frequency of individuals with a short DATE (<28 repeats) in peripheral blood lymphocytes (PBLs) was significantly higher in bladder cancer patients compared to controls (p<0.001). Somatic mutations were observed in 37 of 70 bladder tumor (BT) tissues and the frequency of mutation to long DATE was significantly higher than that to short DATE (p=0.047). The presence of the short DATE in BT tissue was significantly associated with higher tumor grade (p=0.015). HGF mRNA levels were significantly higher in pT2 tumors than pTa or pT1 tumors (p=0.019), and in grade 3 tumors than grade 1 or 2 tumors (p=0.020). Furthermore, BT tissues with the short DATE showed significantly higher levels of HGF mRNA (p<0.001). In patients who underwent radical cystectomy, those with higher HGF expression had a significantly shorter overall survival than those with lower HGF expression (p=0.012). In conclusion, HGF may be associated with the prognosis of patients who undergo radical cystectomy, and the HGF DATE may affect the risk and aggressiveness of bladder cancer by altering HGF expression.
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Affiliation(s)
- Syuji Chiba
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Norihiko Tsuchiya
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Yohei Horikawa
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Shintaro Narita
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takamitsu Inoue
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Susumu Akihama
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Mitsuru Saito
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Kazuyuki Numakura
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Hiroshi Tsuruta
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Mingguo Huang
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Shigeru Satoh
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Tomonori Habuchi
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
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3
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Cheng CC, Jian YH, Lo CJ, Cheng JW. Design and Characterization of a Short HMG-I/DAT1Peptide that Binds Specifically to the Minor Groove of DNA. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.199800093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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4
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Wang T, Hou G, Wang Y, Xue L. Characterization and heterologous expression of a new matrix attachment region binding protein from the unicellular green alga Dunaliella salina. J Biochem 2010; 148:651-8. [PMID: 20926505 DOI: 10.1093/jb/mvq100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) are implicated in various nuclear functions, the understanding of the regulatory mechanism of MARs is still poor. A few MAR-binding proteins (MARBP) have been isolated from some plants and animals, but not from the unicellular algae. Here, we identify a novel MAR-binding protein, namely DMBP-1, from the halotolerant alga Dunaliella salina. The cDNA of DMBP-1 is 2322-bp long and contains a 1626 bp of an open reading frame encoding a polypeptide of 542 amino acids (59 kDa). The DMBP-1 expressed in Escherichia coli specifically binds A/T-rich MAR DNA. The DMBP-1 fused to green fluorescent protein appears only inside the nuclei of Chinese hamster ovarian cells transfected with the pEGFP-MBP, indicating that the protein is located in the nuclei. The findings mentioned above may contribute to better understanding of the nuclear matrix-MAR interactions.
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Affiliation(s)
- Tianyun Wang
- Laboratory for Cell Biology, The First Affiliated Hospital, Zhengzhou University, 40 Daxue Road, Henan, China
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5
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Ma J, DeFrances MC, Zou C, Johnson C, Ferrell R, Zarnegar R. Somatic mutation and functional polymorphism of a novel regulatory element in the HGF gene promoter causes its aberrant expression in human breast cancer. J Clin Invest 2009; 119:478-91. [PMID: 19188684 DOI: 10.1172/jci36640] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 12/10/2008] [Indexed: 11/17/2022] Open
Abstract
The HGF gene is transcriptionally silenced in normal differentiated breast epithelial cells, but its repression fails to occur in mammary carcinoma tissues and cell lines. The molecular mechanisms underpinning aberrant HGF expression in breast cancer cells are unknown. Here we report the discovery of a DNA element located 750 bp upstream from the transcription start site in the human HGF promoter that acts as a transcriptional repressor and is a target of deletion mutagenesis in human breast cancer cells and tissues. This HGF promoter element consists of a mononucleotide repeat of 30 deoxyadenosines (30As), which we have termed "deoxyadenosine tract element" (DATE). Functional studies revealed that truncation mutations within DATE have profound local and global effects on the HGF promoter region by modulating chromatin structure and DNA-protein interactions, leading to constitutive activation of the HGF promoter in human breast carcinoma cell lines. We found that 51% of African Americans and 15% of individuals of mixed European descent with breast cancer harbor a truncated DATE variant (25As or fewer) in their breast tumors and that the truncated allele is associated with cancer incidence and aberrant HGF expression. Notably, breast cancer patients with the truncated DATE variant are substantially younger than those with a wild-type genotype. We also suggest that DATE may be used as a potential genetic marker to identify individuals with a higher risk of developing breast cancer.
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Affiliation(s)
- Jihong Ma
- Division of Experimental Pathology, Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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6
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Wu WS, Li WH, Chen BS. Computational reconstruction of transcriptional regulatory modules of the yeast cell cycle. BMC Bioinformatics 2006; 7:421. [PMID: 17010188 PMCID: PMC1637117 DOI: 10.1186/1471-2105-7-421] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Accepted: 09/29/2006] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND A transcriptional regulatory module (TRM) is a set of genes that is regulated by a common set of transcription factors (TFs). By organizing the genome into TRMs, a living cell can coordinate the activities of many genes and carry out complex functions. Therefore, identifying TRMs is helpful for understanding gene regulation. RESULTS Integrating gene expression and ChIP-chip data, we develop a method, called MOdule Finding Algorithm (MOFA), for reconstructing TRMs of the yeast cell cycle. MOFA identified 87 TRMs, which together contain 336 distinct genes regulated by 40 TFs. Using various kinds of data, we validated the biological relevance of the identified TRMs. Our analysis shows that different combinations of a fairly small number of TFs are responsible for regulating a large number of genes involved in different cell cycle phases and that there may exist crosstalk between the cell cycle and other cellular processes. MOFA is capable of finding many novel TF-target gene relationships and can determine whether a TF is an activator or/and a repressor. Finally, MOFA refines some clusters proposed by previous studies and provides a better understanding of how the complex expression program of the cell cycle is regulated. CONCLUSION MOFA was developed to reconstruct TRMs of the yeast cell cycle. Many of these TRMs are in agreement with previous studies. Further, MOFA inferred many interesting modules and novel TF combinations. We believe that computational analysis of multiple types of data will be a powerful approach to studying complex biological systems when more and more genomic resources such as genome-wide protein activity data and protein-protein interaction data become available.
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Affiliation(s)
- Wei-Sheng Wu
- Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Wen-Hsiung Li
- Department of Evolution and Ecology, University of Chicago, 1101 East 57th Street, Chicago, IL, 60637, USA
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Bor-Sen Chen
- Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
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7
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Morisawa G, Han-Yama A, Moda I, Tamai A, Iwabuchi M, Meshi T. AHM1, a novel type of nuclear matrix-localized, MAR binding protein with a single AT hook and a J domain-homologous region. THE PLANT CELL 2000; 12:1903-16. [PMID: 11041885 PMCID: PMC149128 DOI: 10.1105/tpc.12.10.1903] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2000] [Accepted: 07/20/2000] [Indexed: 05/18/2023]
Abstract
Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.
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Affiliation(s)
- G Morisawa
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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8
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Horn J, Dietz-Schmidt A, Zündorf I, Garin J, Dingermann T, Winckler T. A Dictyostelium protein binds to distinct oligo(dA) x oligo(dT) DNA sequences in the C-module of the retrotransposable element DRE. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 265:441-8. [PMID: 10491202 DOI: 10.1046/j.1432-1327.1999.00768.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The genome of the eukaryotic microbe Dictyostelium discoideum contains some 200 copies of the nonlong-terminal repeat retrotransposon DRE. Among several unique features of this retroelement, DRE is transcribed in both directions leading to the formation of partially overlapping plus strand and minus strand RNAs. The synthesis of minus strand RNAs is controlled by the C-module, a 134-bp DNA sequence located at the 3'-end of DRE. A nuclear protein (CMBF) binds to the C-module via interaction with two almost homopolymeric 24 bp oligo(dA) x oligo(dT) sequences. The DNA-binding drugs distamycin and netropsin, which bind to A x T-rich DNA sequences in the minor groove, competed efficiently for the binding of CMBF to the C-module. The CMBF-encoding gene, cbfA, was isolated and a DNA-binding domain was mapped to a 25-kDa C-terminal region of the protein. A peptide motif involved in the binding of A x T-rich DNA by high mobility group-I proteins ('GRP' box) was identified in the deduced CMBF protein sequence, and exchange of a consensus arginine residue for alanine within the CMBF GRP box abolished the interaction of CMBF with the C-module. The current data support the theory that CMBF binds to the C-module by detecting its long-range DNA conformation and interacting with A x T base pairs in the minor groove of oligo(dA) x oligo(dT) stretches.
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Affiliation(s)
- J Horn
- Institut für Pharmazeutische Biologie, Universität Frankfurt/Mainz (Biozentrum), Frankfurt, Germany
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9
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Hatton D, Gray JC. Two MAR DNA-binding proteins of the pea nuclear matrix identify a new class of DNA-binding proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 18:417-29. [PMID: 10406125 DOI: 10.1046/j.1365-313x.1999.00468.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: 05/23/2023]
Abstract
Four MAR-binding proteins of 60, 65, 70 and 72 kDa have been detected by South-Western blotting and isolated from pea nuclear matrices. Two cDNAs encoding the 60 and 65 kDa proteins (MARBP-1 and MARBP-2) were isolated from a pea leaf cDNA library by screening with a PCR product obtained using degenerate primers based on an amino acid sequence from the 60 kDa protein. The proteins of 560 and 550 amino acids are 86% identical and contain several KKD/E repeats near the C-terminus. Escherichia coli-expressed MARBP-1 specifically binds A/T-rich MAR DNA. The interaction of MARBP-1/MARBP-2 with MAR DNA involves novel DNA-binding motifs. The MARBP-1 and MARBP-2 genes are expressed in a range of pea tissues and are encoded by genes at different loci. MARBP-1 and MARBP-2 are homologous to yeast nucleolar proteins Nop56p and Nop58p, which are involved in ribosome biogenesis, and to similar highly conserved proteins in other eukaryotes and in archaebacteria. MARBP-1 and MARBP-2 may have multifunctional roles in chromatin organisation and ribosome biogenesis.
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Affiliation(s)
- D Hatton
- Department of Plant Sciences, University of Cambridge, UK
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10
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Jones PL, Jones FS, Zhou B, Rabinovitch M. Induction of vascular smooth muscle cell tenascin-C gene expression by denatured type I collagen is dependent upon a beta3 integrin-mediated mitogen-activated protein kinase pathway and a 122-base pair promoter element. J Cell Sci 1999; 112 ( Pt 4):435-45. [PMID: 9914156 DOI: 10.1242/jcs.112.4.435] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Tenascin-C is an extracellular matrix glycoprotein, the expression of which is upregulated in remodeling arteries. In previous studies we showed that the presence of tenascin-C alters vascular smooth muscle cell shape and amplifies their proliferative response by promoting growth factor receptor clustering and phosphorylation. Moreover, we demonstrated that denatured type I collagen induces smooth muscle cell tenascin-C protein production via beta3 integrins. In the present study, we examine the pathway by which beta3 integrins stimulate expression of tenascin-C, and define a promoter sequence that is critical for its induction. On native collagen, A10 smooth muscle cells adopt a stellate morphology and produce low levels of tenascin-C mRNA and protein, whereas on denatured collagen they spread extensively and produce high levels of tenascin-C mRNA and protein, which is incorporated into an elaborate extracellular matrix. Increased tenascin-C synthesis on denatured collagen is associated with elevated protein tyrosine phosphorylation, including activation of extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2). beta3 integrin function-blocking antibodies attenuate ERK1/2 activation and tenascin-C protein synthesis. Consistent with these findings, treatment with the specific MEK inhibitor, PD 98059, results in suppression of tenascin-C protein synthesis. To investigate whether beta3 integrin-dependent activation of ERK1/2 regulates the tenascin-C promoter, we transfected A10 cells with a full-length (approx. 4 kb) mouse tenascin-C gene promoter-chloramphenicol acetyltransferse reporter construct and showed that, relative to native collagen, its activity is increased on denatured collagen. Next, to identify regions of the promoter involved, we examined a series of tenascin-C promoter constructs with 5′ deletions and showed that denatured collagen-dependent promoter activity was retained by a 122-base pair element, located -43 to -165 bp upstream of the RNA start site. Activation of this element was suppressed either by blocking beta3 integrins, or by preventing ERK1/2 activation. These observations demonstrate that smooth muscle cell binding to beta3 integrins activates the mitogen activated protein kinase pathway, which is required for the induction of tenascin-C gene expression via a potential extracellular matrix response element in the tenascin-C gene promoter. Our data suggest a mechanism by which remodeling of type I collagen modulates tenascin-C gene expression via a beta3 integrin-mediated signaling pathway, and as such represents a paradigm for vascular development and disease whereby smooth muscle cells respond to perturbations in extracellular matrix composition by altering their phenotype and patterns of gene expression.
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Affiliation(s)
- P L Jones
- Division of Cardiovascular Research, Research Institute, The Hospital for Sick Children, Department of Pediatrics, University of Toronto, Ontario, Canada M5G 1X8.
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11
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Reardon BJ, Lombardo CR, Sander M. Drosophila Rrp1 domain structure as defined by limited proteolysis and biophysical analyses. J Biol Chem 1998; 273:33991-9. [PMID: 9852053 DOI: 10.1074/jbc.273.51.33991] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Drosophila Rrp1 is a DNA repair nuclease whose C-terminal region shares extensive homology with Escherichia coli exonuclease III, has nuclease activity, and provides resistance to oxidative and alkylating agents in repair-deficient E. coli strains. The N-terminal 421 amino acid region of Rrp1, which binds and renatures homologous single-stranded DNA, does not share homology with any known protein. Proteolysis by endoproteinase Glu-C (protease V8) reduces the Rrp1 protein to a single, cleavage-resistant peptide. The peptide (referred to as Rrp1-C274) begins with the sequence TKTTV, corresponding to cleavage between Glu-405 and Thr-406 of Rrp1. We determined that nuclease activity is intrinsic to Rrp1-C274 although altered when compared with Rrp1; 3'-exonuclease activity is reduced 210-fold, 3'-phosphodiesterase activity is reduced 6.8-fold, and no difference in apurinic/apyrimidinic endonuclease activity is observed. Rrp1 and Rrp1-C274 are both monomers with frictional coefficients of 2.2 and 1.4, respectively. Circular dichroism results indicate that Rrp1-C274 is predominantly alpha-helical, while the N-terminal 399 amino acids is predominantly random coil. These results suggest that Rrp1 may have a bipartite structural organization; a highly organized, globular C-terminal domain; and an asymmetric, protease-sensitive random coil-enriched N-terminal region. A shape model for this bipartite structure is proposed and discussed.
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Affiliation(s)
- B J Reardon
- Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
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12
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Nadir E, Margalit H, Gallily T, Ben-Sasson SA. Microsatellite spreading in the human genome: evolutionary mechanisms and structural implications. Proc Natl Acad Sci U S A 1996; 93:6470-5. [PMID: 8692839 PMCID: PMC39047 DOI: 10.1073/pnas.93.13.6470] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Microsatellites are tandem repeat sequences abundant in the genomes of higher eukaryotes and hitherto considered as "junk DNA." Analysis of a human genome representative data base (2.84 Mb) reveals a distinct juxtaposition of A-rich microsatellites and retroposons and suggests their coevolution. The analysis implies that most microsatellites were generated by a 3'-extension of retrotranscripts, similar to mRNA polyadenylylation, and that they serve in turn as "retroposition navigators," directing the retroposons via homology-driven integration into defined sites. Thus, they became instrumental in the preservation and extension of primordial genomic patterns. A role is assigned to these reiterating A-rich loci in the higher-order organization of the chromatin. The disease-associated triplet repeats are mostly found in coding regions and do not show an association with retroposons, constituting a unique set within the family of microsatellite sequences.
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Affiliation(s)
- E Nadir
- Department of Molecular Genetics, Hebrew University, Hadassah Medical School, Jerusalem, Israel
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13
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Botella LM, Nieto A. The C-terminal DNA-binding domain of Chironomus BR gene products shows preferential affinity for (dA.dT)-rich sequences. MOLECULAR & GENERAL GENETICS : MGG 1996; 251:422-7. [PMID: 8709945 DOI: 10.1007/bf02172370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Balbiani ring genes (BRs), the most active loci in the polytene chromosomes of the salivary gland of the midge Chironomus (Diptera), code for secretory giant peptides (the sp-I family). Evidence previously reported indicated that the conserved C-terminal region of proteins of the sp-I family had DNA-binding properties (assayed with sp-Ia), and one such region, derived from BR2.2, which codes for the product sp-Ib, might occur as a stable independent peptide, being transferred to the nucleus where it is detectable in the large BRs (BR1 and BR2), among other structures, by immunostaining. Here, we show that the C-terminal portion of one of the BR gene products, expressed as a glutathione-S-transferase fusion protein shows preferential affinity for A.T-rich sequences and binds with varying affinity to restriction fragments of the A.T-rich BR1 promoter. The binding was inhibited by distamycin, suggesting that the interaction involves the minor groove of the DNA. Analysis of the promoter fragments by gel electrophoresis indicated that most appeared to present a conspicuous bend, as deduced from their anomalous electrophoretic mobilities. Furthermore, the affinity of the C-terminal domain for the different promoter fragments appeared to correlate with the degree of bending. Thus, the C-terminal domain might play a role in controlling gene expression by binding to A.T-rich sequences, including those of the BR genes.
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Affiliation(s)
- L M Botella
- Departmento de Biologia Celular y del Desarrollo, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
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14
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Reardon BJ, Gordon D, Ballard MJ, Winter E. DNA binding properties of the Saccharomyces cerevisiae DAT1 gene product. Nucleic Acids Res 1995; 23:4900-6. [PMID: 8532535 PMCID: PMC307481 DOI: 10.1093/nar/23.23.4900] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The DAT1 gene of Saccharomyces cerevisiae encodes a DNA binding protein (Dat1p) that specifically recognizes the minor groove of non-alternating oligo(A).oligo(T) tracts. Sequence-specific recognition requires arginine residues found within three perfectly repeated pentads (G-R-K-P-G) of the Dat1p DNA binding domain [Reardon, B. J., Winters, R. S., Gordon, D., and Winter, E. (1993) Proc. Natl. Acad. Sci. USA 90, 11327-1131]. This report describes a rapid and simple method for purifying the Dat1p DNA binding domain and the biochemical characterization of its interaction with oligo(A).oligo(T) tracts. Oligonucleotide binding experiments and the characterization of yeast genomic Dat1p binding sites show that Dat1p specifically binds to any 11 base sequence in which 10 bases conform to an oligo(A).oligo(T) tract. Binding studies of different sized Dat1p derivatives show that the Dat1p DNA binding domain can function as a monomer. Competition DNA binding assays using poly(I).poly(C), demonstrate that the minor groove oligo(A).oligo(T) constituents are not sufficient for high specificity DNA binding. These data constrain the possible models for Dat1p/oligo(A).oligo(T) complexes, suggest that the DNA binding domain is in an extended structure when complexed to its cognate DNA, and show that Dat1p binding sites are more prevalent than previously thought.
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Affiliation(s)
- B J Reardon
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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15
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Chen L, Frankel AD. A peptide interaction in the major groove of RNA resembles protein interactions in the minor groove of DNA. Proc Natl Acad Sci U S A 1995; 92:5077-81. [PMID: 7761451 PMCID: PMC41851 DOI: 10.1073/pnas.92.11.5077] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A 17-amino acid arginine-rich peptide from the bovine immunodeficiency virus Tat protein has been shown to bind with high affinity and specificity to bovine immunodeficiency virus transactivation response element (TAR) RNA, making contacts in the RNA major groove near a bulge. We show that, as in other peptide-RNA complexes, arginine and threonine side chains make important contributions to binding but, unexpectedly, that one isoleucine and three glycine residues also are critical. The isoleucine side chain may intercalate into a hydrophobic pocket in the RNA. Glycine residues may allow the peptide to bind deeply within the RNA major groove and may help determine the conformation of the peptide. Similar features have been observed in protein-DNA and drug-DNA complexes in the DNA minor groove, including hydrophobic interactions and binding deep within the groove, suggesting that the major groove of RNA and minor groove of DNA may share some common recognition features.
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Affiliation(s)
- L Chen
- Department of Biochemistry and Biophysics, University of California, San Francisco 94141, USA
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16
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Copertino DW, Jenkinson S, Jones FS, Edelman GM. Structural and functional similarities between the promoters for mouse tenascin and chicken cytotactin. Proc Natl Acad Sci U S A 1995; 92:2131-5. [PMID: 7534412 PMCID: PMC42437 DOI: 10.1073/pnas.92.6.2131] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cytotactin/tenascin is an extracellular matrix glycoprotein expressed in a restricted anteroposterior pattern during vertebrate development and is reexpressed in the adult during wound healing, tumorigenesis, and nerve regeneration. Previously, we have characterized the chicken cytotactin promoter and have shown its regulation by homeobox gene products in vitro. We have now isolated the promoter for the mouse tenascin gene in order to determine whether common or different DNA regulatory elements control the expression of this gene in these two species. Like the chicken cytotactin gene, the mouse tenascin gene has a single RNA start site that lies 27 bp downstream of a TATA box. A 4028-bp region of DNA upstream of the mouse tenascin gene was sequenced and examined for regulatory motifs in common with the upstream sequence from the chicken cytotactin promoter. Two hundred thirty base pairs of the proximal promoter regions from both genes had an extended sequence similarity and contained common regulatory motifs such as two tracts of homopolymeric dA.dT sequence, an octamer motif, an ATTA (TAAT) motif which is a common core sequence for binding of homeodomain transcription factors, and a TATA-box/cap-site region. Reporter gene constructs with various 5' deletions of the mouse tenascin upstream sequence were tested in transient transfections of mouse NIH 3T3 and chicken embryo fibroblasts. The conserved proximal promoter region of tenascin was responsible for most of the positive regulatory activity. In addition, an upstream region (-2478 to -247) repressed proximal promoter activity in mouse fibroblasts and also in chicken embryo fibroblasts. These data indicate that both the structure and function of the cytotactin/tenascin proximal promoters have remained conserved over 250 million years.
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Affiliation(s)
- D W Copertino
- Scripps Research Institute, Department of Neurobiology, La Jolla, CA 92037
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