CpG methylation at GATA elements in the regulatory region ofCCR3positively correlates withCCR3transcription

Abstract

DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription.

Promoter identification and analysis of key glycosphingolipid biosynthesis-globo series pathway genes in piglets

“…The CpG islands of FUT1, FUT2, HEXA, HEX, NAGA, and ST3GAL1 were found to contain 20, 11, 14, 18, 23, and 18 putative TFBSs, respectively. Methylation of TFBSs for SP1, CREB, Myc, USF-1, CTCF, GATA-1, and AP-2 decreases the affinity of protein-DNA interactions, thereby lowering the transcription rate (Clark et al, 1997;Perini et al, 2005;Kim and Leonard, 2007;Uhm et al, 2012). We found SP1 TFBSs in all CpG islands identified in the present study.…”

Lysophosphatidylserine receptor P2Y10: A G protein‐coupled receptor that mediates eosinophil degranulation

“…Fresh CB CD34 + cells were immunomagnetically purified from human CB mononuclear cells using a MACS CD34 microbead kit (Miltenyi Biotec). These purified cells were then induced to differentiate into eosinophils for 24 or more days, as previously described in detail . Eosinophilic differentiation was monitored on the basis of granule formation and nucleus shape following staining with Diff‐Quick solution.…”

Allele-specific DNA methylation reinforces PEAR1 enhancer activity

“…20 Although an inverse correlation between DNA methylation and gene expression is very well known, the opposite is not yet well understood, although reported in some large-scale studies 54 and highly dependent on the genomic context. [55][56][57] To better understand this unusual relation between DNA methylation and gene expression, we have studied PEAR1 DNA methylation, during early and late megakaryopoiesis. We found that parallel progressive elevation of PEAR1 CGI1 methylation and PEAR1 expression occurs in early differentiation.…”