InterPro domain: IPR037856

This entry includes Sdc1 from yeasts, and its homologues, Dpy-30, from animals.

Protein dpy-30 homologue (DPY30) is a component of the MLL1/MLL complex which trimethylates histone H3 at 'Lys-4' as a specific tag for epigenetic transcriptional activation [ 1 ]. DPY30 is also a component in MLL2/3 and MLL4/WBP7 methyltransferase-containing complexes [ 2 , 3 ] and the SET1 complex [ 4 ]. DPY30 is found in the nucleus and the trans-Golgi network where it interacts with ARFGEF1 implying a role in endosomal trafficking [ 5 ]. This entry also includes C. elegans dpy-30, which is an essential component of the C. elegans dosage compensation machinery that reduces X chromosome transcript levels in hermaphrodites (XX) [ 6 ].

The SET1 complex is a methyltransferase that that produces trimethylated histone H3 at Lys(4). It is composed of at least the catalytic subunit (SETD1A or SETD1B), WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1 and DPY30 [ 7 ]. In yeast there is only one SET1 complex, but in mammals there are additional H3K4 methylases [ 8 ].

1. On the mechanism of multiple lysine methylation by the human mixed lineage leukemia protein-1 (MLL1) core complex. J. Biol. Chem. 186, 343-53
2. Menin associates with a trithorax family histone methyltransferase complex and with the hoxc8 locus. Mol. Cell 284, 24242-56
3. PTIP associates with MLL3- and MLL4-containing histone H3 lysine 4 methyltransferase complex. J. Biol. Chem. 282, 13419-28
4. Molecular regulation of H3K4 trimethylation by Wdr82, a component of the human Set1/COMPASS. Mol. Cell. Biol. 282, 20395-406
5. A role of histone H3 lysine 4 methyltransferase components in endosomal trafficking. J. Cell Biol.
6. DPY-30, a nuclear protein essential early in embryogenesis for Caenorhabditis elegans dosage compensation. Development 121, 3323-34
7. Identification and characterization of the human Set1B histone H3-Lys4 methyltransferase complex. J. Biol. Chem. 13, 587-97