Characterization and functional dissection of the galactin‐1 gene promoter

Salvatore, Paola; Contursi, Cristina; Benvenuto, Giovanna; Bruni, Carmelo B.; Chiariotti, Lorenzo

doi:10.1016/0014-5793(95)01032-a

Cited by 26 publications

(27 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Seventeen CpG sites, natural substrates of mammalian methyltransferase, are located in this 5Ј region. Interestingly, the majority of these dinucleotides are clustered in a region of about 200 bp (positions Ϫ122 to ϩ81), encompassing the transcription start site, that is sufficient for basal promoter activity (45). A similar distribution of CpG doublets is present in the corresponding region of the mouse (11) and human (23) genes (Fig.…”

Section: Resultsmentioning

confidence: 76%

“…On the other hand, galectin-1 promoter constructs are transactivated by factors present in both expressing and nonexpressing cells (45). To explain this, we postulated that the gene is repressed in nonproducing cells, through a cis-acting mechanism which is nonfunctional on transiently transfected promoters, and is derepressed in the hybrids in a dominant fashion.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Cell-Specific Transcriptional Regulation and Reactivation of Galectin-1 Gene Expression Are Controlled by DNA Methylation of the Promoter Region

Benvenuto

Carpentieri

Salvatore

et al. 1996

Molecular and Cellular Biology

View full text Add to dashboard Cite

The galectin-1 gene is a developmentally regulated gene whose activity is strongly modulated during cell differentiation and transformation. We have previously shown that galectin-1 promoter constructs are highly active when transiently transfected in cells both expressing and not expressing the endogenous gene and that the basal activity is determined by a small region encompassing the transcription start site (from positions ؊50 to ؉50). We have now investigated the role of DNA methylation in galectin-1 gene expression. Southern blot analysis with HpaII and MspI endonucleases and sodium bisulfite analysis of genomic DNA from expressing and nonexpressing cell lines and cell hybrids showed a close correlation between gene activity and demethylation of the 5 region of the galectin-1 gene. We found that the galectin-1 promoter region is fully methylated, at every CpG site on both strands, in nonexpressing differentiated rat liver (FAO) and thyroid (PC Cl3) cells and unmethylated in the expressing undifferentiated liver (BRL3A) and thyroid transformed (PC myc/raf) cell lines. In addition, reactivation of the silent FAO alleles in the FAO-human osteosarcoma (143TK ؊ ) hybrid cells is accompanied by a complete demethylation of the promoter region. Finally, when galectin-1-chloramphenicol acetyltransferase (CAT) promoter constructs were methylated in vitro by SssI methylase at every cytosine residue of the CpG doublets and transfected into mouse fibroblasts, the transcription of the CAT reporter gene was strongly inhibited.Mammalian lectins are a growing class of proteins that share the presence of a carbohydrate recognition domain and are involved in several biological processes (17). Changes in the expression of endogenous lectins and abnormal glycosylation may both result in altered protein-carbohydrate interactions and are characteristic of a number of diseases, including autoimmune diseases and cancer (17). In this work, we investigated whether changes in DNA methylation, which are frequently associated with differentiation and transformation events (28, 43), can account for variations in the expression of the endogenous lectin galectin-1 (2, 3).Galectin-1 appears to play a key role in different biological processes, such as cell growth control (37, 40, 51, 52), cell-cell and cell-matrix interactions, including acquisition of the metastatic phenotype (14,22,34,50), and the maturation of Tlymphoblastoid cells (5). The expression of galectin-1 is strongly modulated during development (38) and increases dramatically with transformation and loss of differentiated functions both in cell lines (10, 41) and in mammalian tissues (9, 27). By contrast, treatment of transformed neural cells with differentiating agents leads to extinction of galectin-1 expression (7, 33). Nuclear run-on experiments showed that regulation of this gene occurs, at least in part, at the transcriptional level (10). To date, however, little is known concerning the mechanisms whereby transformation and loss of differentiation lead to transcriptiona...

show abstract

Section: Resultsmentioning

confidence: 76%

mentioning

confidence: 99%

Cell-Specific Transcriptional Regulation and Reactivation of Galectin-1 Gene Expression Are Controlled by DNA Methylation of the Promoter Region

Benvenuto

Carpentieri

Salvatore

et al. 1996

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…Next we questioned whether MBDin could reactivate transcription from methylated promoters. For this purpose we used a plasmid construct containing 1,700 bp of the mouse galectin-1 promoter upstream of a CAT reporter gene (pGAT1700) (36). It was previously demonstrated that galectin-1 promoter constructs are repressed by in vitro DNA methylation (4).…”

Section: Resultsmentioning

confidence: 99%

MBDin, a Novel MBD2-Interacting Protein, Relieves MBD2 Repression Potential and Reactivates Transcription from Methylated Promoters

Lembo

Pero

Angrisano

et al. 2003

Molecular and Cellular Biology

Self Cite

View full text Add to dashboard Cite

We have identified a human gene encoding a novel MBD2-interacting protein (MBDin) that contains an N-terminal GTP-binding site, a putative nuclear export signal (NES), and a C-terminal acidic region. MBDin cDNA was isolated through a two-hybrid interaction screening using the methyl-CpG-binding protein MBD2 as bait. The presence of the C-terminal 46-amino-acid region of MBD2 and both the presence of the acidic C-terminal 128-amino-acid region and the integrity of the GTP-binding site of MBDin were required for the interaction. Interaction between MBD2 and MBDin in mammalian cells was confirmed by immunoprecipitation experiments. Fluorescence imaging experiments demonstrated that MBDin mainly localizes in the cytoplasm but accumulates in the nucleus upon disruption of the NES or treatment with leptomycin B, an inhibitor of NES-mediated transport. We also found that MBDin partially colocalizes with MBD2 at foci of heavily methylated satellite DNA. An MBD2 deletion mutant lacking the C-terminal region maintained its subnuclear localization but failed to recruit MBDin at hypermethylated foci. Functional analyses demonstrated that MBDin relieves MBD2-mediated transcriptional repression both when Gal4 chimeric constructs and when in vitro-methylated promoter-reporter plasmids were used in transcriptional assays. Southern blotting and bisulfite analysis showed that transcriptional reactivation occurred without changes of the promoter methylation pattern. Our findings suggest the existence of factors that could be targeted on methylated DNA by methyl-CpG-binding proteins reactivating transcription even prior to demethylation.Addition of methyl groups mostly at the CpG dinucleotide represents the major epigenetic modification of eukaryotic genomes heritable by somatic cells after cell division. DNA methylation plays an essential role in mammalian development (24) and in different biological processes such as tissue-specific gene expression (40), X-chromosome inactivation (17), genomic imprinting (2, 33), and repression of transposable elements (46). Abnormal methylation is a cause of human genetic diseases, including ICF syndrome (16), and is involved in carcinogenic processes primarily through aberrant hypermethylation of tumor suppressors' promoter regions (12,21,22).Methylated DNA is generally associated with transcriptional silencing (6, 7, 32), but how DNA methylation silences gene expression is not well understood. Studies are now focusing on the different components of the DNA methylation system and particularly on the mechanisms by which methyl-CpG signal is targeted, read, and maintained. Recently, a family of five mammalian methyl-CpG-binding proteins (MeCP2, MBD1, MBD2, MBD3, and MBD4) has been found to be essential to interpret the methylation patterns and to mediate the biological consequences of DNA methylation (1, 15, 18). All methyl-binding proteins share a common structural stretch of 60 to 80 amino acids called the mCpG-binding domain (MBD) and, with the exception of MBD4 (19, 34), mediate transcription...

show abstract

“…Among the parsimony reconstructions (i.e., ACCTRAN and DELTRAN) and maximum likelihood (ML) reconstructions of ancestral states on the species tree, several functionally important replacements occurred in which derived cysteines would have resulted LGALS1 directs the transcription of two distinct-length mRNAs encoding for the same protein in humans and mice, and the transcription initiation for both transcripts is mediated by the Inr, TATA box, and SP1 binding site, the latter of which is crucial for the basal LGALS1 expression (35)(36)(37)(38). From the conserved cis elements (AP-2, yellow boxes; AP-4, black boxes, CAAT box-binding protein, white boxes; CAC-binding protein, gray boxes; C/EBP-␣, pink boxes; c-ETS-2, brown boxes; ERE, red boxes; HSF-1, orange boxes; NF-1, light blue boxes, NF-Y, dark blue boxes; and SP1, green boxes), 10 have been gained on the stem of placental mammals.…”

Section: C) (D)mentioning

confidence: 99%

“…Indeed, the stem of placental mammals underwent a gain of 10 cis elements, including a highly conserved half ERE, an overlapping NF-Y, and a nearby AP-2 motif, which were identified in humans and mice but functionally not yet characterized (35)(36)(37). Estrogens act through estrogen receptors that are involved in the stimulation of uterine growth, progesterone receptor expression, and immunoregulation (39).…”

Section: Ere May Participate In Regulation Of Uterine/placentalmentioning

confidence: 99%

Emergence of hormonal and redox regulation of galectin-1 in placental mammals: Implication in maternal–fetal immune tolerance

Than

Romero²,

Erez³

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Galectin-1 is an anti-inflammatory lectin with pleiotropic regulatory functions at the crossroads of innate and adaptive immunity. It is expressed in immune privileged sites and is implicated in establishing maternal-fetal immune tolerance, which is essential for successful pregnancy in eutherian mammals. Here, we show conserved placental localization of galectin-1 in primates and its predominant expression in maternal decidua. Phylogenetic footprinting and shadowing unveil conserved cis motifs, including an estrogen responsive element in the 5 promoter of LGALS1, that were gained during the emergence of placental mammals and could account for sex steroid regulation of LGALS1 expression, thus providing additional evidence for the role of galectin-1 in immuneendocrine cross-talk. Maximum parsimony and maximum likelihood analyses of 27 publicly available vertebrate and seven newly sequenced primate LGALS1 coding sequences reveal that intense purifying selection has been acting on residues in the carbohydrate recognition domain and dimerization interface that are involved in immune functions. Parsimony-and codon model-based phylogenetic analysis of coding sequences show that amino acid replacements occurred in early mammalian evolution on key residues, including gain of cysteines, which regulate immune functions by redox status-mediated conformational changes that disable sugar binding and dimerization, and that the acquired immunoregulatory functions of galectin-1 then became highly conserved in eutherian lineages, suggesting the emergence of hormonal and redox regulation of galectin-1 in placental mammals may be implicated in maternal-fetal immune tolerance.decidua ͉ estrogen ͉ glycocode ͉ immune-endocrine cross-talk ͉ pregnancy T he success of mammalian pregnancy, in which the developing fetus and mother exchange nutrients, gases, and other molecules via the chorioallantoic placenta, requires maternal immune tolerance to fetal allo-antigens (1-4). This tolerance presumably prevents the occurrence of exaggerated inflammation at the implantation site and reduces the danger of destructive immune attacks on the fetus, a danger that the first mammals with an invasive placenta would have faced (5, 6). It seems likely that mechanisms for immune tolerance to invasive placentation were already functioning in the early placental mammals and that immunoregulatory molecules, which had existed before the mammalian placenta evolved, were incorporated in this tolerance and have undergone evolutionary modifications coincident with the emergence of the mammalian placenta. Here, we present evidence that such modifications occurred in a key immunoregulatory molecule, galectin-1.Molecules that have been implicated in conferring maternalfetal immune tolerance include galectin-1, B7 proteins, Crry, Fas ligand, HLA-G, indoleamine 2,3-dioxygenase, and killer cell immunoglobulin-like receptors (2-4, 7-11). These proteins are involved in pathways regulating adaptive or innate immune responses at the maternal-fetal interface, and their di...

show abstract

Characterization and functional dissection of the galactin‐1 gene promoter

Cited by 26 publications

References 29 publications

Cell-Specific Transcriptional Regulation and Reactivation of Galectin-1 Gene Expression Are Controlled by DNA Methylation of the Promoter Region

Cell-Specific Transcriptional Regulation and Reactivation of Galectin-1 Gene Expression Are Controlled by DNA Methylation of the Promoter Region

MBDin, a Novel MBD2-Interacting Protein, Relieves MBD2 Repression Potential and Reactivates Transcription from Methylated Promoters

Emergence of hormonal and redox regulation of galectin-1 in placental mammals: Implication in maternal–fetal immune tolerance

Contact Info

Product

Resources

About