Geeliä muodostava musiini MUC2,Geeni kr. 5 p15.5

http://atlasgeneticsoncology.org/Genes/MUC2ID41457ch11p15.html
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MUC2 is located within a 29-kb DNA fragment between MUC6, MUC5AC and MUCB on chromosome 11 in the region p15.5 (Griffiths et al., 1990; Desseyn et al., 1998; Rousseau et al., 2004), and cDNA is approximately 15.5 kb long. Genes that share some sequence homology are believed to have arisen by duplication from a common ancestor.

Transcription

The MUC2 promoter contains a TATA box, and includes binding sequence motifs for transcription factors such as AP2, SP1 and CDX2 (Griffiths et al., 1990; Toribara et al., 1991; Gum et al., 1994). MUC2 expression has been reported to be regulated by the Sp family (Nogami et al., 1997; Aslam et al., 2001). SP1 activates transcription synergistically both close to and far from the transcription start site in an enhancer-like manner. In several human cancer cell lines, p53 has also been indicated to regulate MUC2 transactivation by binding to two of its sites (-1131/-1100 and -676/-650) (Ookawa et al., 2002). Moreover, NF-kB and CDX2 have been reported to up-regulate MUC2 transcription (Yamamoto et al., 2003; Ikeda et al., 2007). Methylation of cytosine residues at CpG dinucleotides is an important epigenetic change that has been linked to transcriptional repression and regulation of chromatin structure (Holliday et al., 1975; Meehan et al., 2001; Recillas-Targa et al., 2002). Increased methylation of promoter region causes suppression of MUC2 gene (Hanski et al., 1997b; Riede et al., 1998). Hamada et al. have determined the detailed methylation status of a wide area of the MUC2 promoter region in pancreatic cancer cell lines, and suggested that methylation of certain CpG sites may play a particularly important role in the regulation of MUC2 transcription (Hamada et al., 2005). A CDX2 binding site is present downstream of the MUC2 promoter, and Yamamoto et al. have reported that the homeodomain protein CDX2 interacts with the MUC2-WT cis element (bases -201 to -162) in the MUC2 promoter and that ectopic expression of the CDX2 protein activates transcription of MUC2 (Yamamoto et al., 2003). In bisulfite genomic sequencing study, CDX2-binding CpG site showed 95% methylation in PANC1 (MUC2-negative) and 50% methylation in BxPC3 (MUC2-positive) (Hamada et al., 2005). Thus, MUC2 expression might be regulated by epigenetic changes in the promoter region containing the CDX2 binding site. In addition to DNA methylation, H3-K9 methylation is closely related to DNA methylation and acts as an epigenetic marker for silencing of the MUC2 gene (Yamada et al., 2006; Vincent et al., 2007).