Figure 15. Model of chromatin architecture and transcription regulatory elements in XL9 and DQB1 segments.
(A) (i-ii) A model showing the XL9 transcription complex and three important proteins (CTCF, IRF4 and ZNF143) which may be impacted by SLE associated genetic variants hitting canonical motifs in XL9 region (Adapted from Majumdar et al., 2008). The chromatin structure of the regulatory complex produced in the DQB1 5’ segment is hypothetical and currently unknown. A chromosomal map of HLA-DRB1 through HLA-DQB1 region showing ENCODE defined regulatory marks, eQTLs and most strongly impacted transcription factors by XL9 and the DQB1 5’segment is shown below these models. The transcription factor binding sites impacted by functional variations within these regions are shown below the molecular map. (A) (iii) A table listing the numbers of and characteristics of functional variants in these two regulatory regions of HLA-D. (B): Global distribution of the major risk and protective haplotypes from the composite HLA-D region analysis.