Differential methylation pattern of the X-linked lymphoproliferative (XLP) disease gene SH2D1A correlates with the cell lineage-specific transcription.

SH2D1A, the X-linked lymphoproliferative disease (XLP) gene, encodes a cytoplasmic protein that plays an essential role in controlling Epstein-Barr virus infection. It is expressed in T and NK cells, but not in B cells or in granulocytes. The promoter, the regulatory regions, as well as the mechanisms controlling its tissue-specific expression, are still unknown. We tested the hypothesis that DNA methylation might contribute to tissue-specific SH2D1A gene expression and analyzed the methylation status of 2,300 bp upstream of the ATG starting codon, the coding region and part of intron 1. By bisulfite sequencing and methylation-sensitive restriction enzyme digestion, we show that a differential methylation pattern of CpG-rich regions in the 5' region and the adjacent exon 1 of the SH2D1A gene indeed correlates with the tissue-specific gene transcription.