WDR5: ProductsWDR5 (WD repeat-containing protein 5; also BMP2-induced 3 kb gene protein/BIG3) is a nuclear, 36-40 kDa monomeric member of the WD family of repeat proteins. It is known to be expressed in osteoblasts, osteocytes and chrondrocytes, among other cells, and appears to serve as a structural organizer for the histone methyltransferase MLL1 complex. This complex methylates histone H3, and within this complex, WDR5 binds to mono- or dimethylated histone H3 and serves as an anchor for complex subunits RbBP5, Ash2L and MLL1. Human WDR5 is 334 amino acids (aa) in length. It contains seven WD domains (aa 43-333) that likely participate in protein-protein interactions, plus a phosphorylation site at Ser267. There are three isoform variants for WDR5. Human and mouse WDR5 are absolutely identical in aa sequence.