PHD finger found in death-inducer obliterator variants Dido1, Dido2, and Dido3
This family includes three alternative splicing variants (Dido1, 2, and 3) encoded by the Dido gene, which have been implicated in a number of cellular processes such as apoptosis and chromosomal segregation, particularly in the hematopoietic system. Dido1, also termed DIO-1, or death-associated transcription factor 1 (DATF-1), is important for maintaining embryonic stem (ES) cells and directly regulates the expression of pluripotency factors. It is the shortest isoform that contains only a highly conserved plant homeodomain (PHD) finger responsible for the binding of histone H3 with a higher affinity for trimethylated lysine 4 (H3K4me3). Gene Dido is a Bonemorphogenetic protein (BMP) target gene, which promotes BMP-induced melanoma progression. It also triggers apoptosis after nuclear translocation and caspase upregulation. Dido3 is the largest isoform ubiquitously expressed in all human tissues. It is dispensable for ES cell self-renewal and pluripotency, but involved in the maintenance of stem cell genomic stability and tumorigenesis. Dido3 contains a PHD finger, a transcription elongation factor S-II subunit M (TFSIIM) domain, aspen paralog and ortholog (SPOC) module, and a long C-terminal region (CT) of unknown homology. Its PHD finger interacts with H3K4me3.