Genome-wide studies of histone Me2 SWIRM and polyamine oxidase domain homologues of mammalian LSD1

In order to gain a more global view of the activity of histone demethylases we report here studies of the two fission yeast SWIRM and polyamine oxidase domain homologues of mammalian LSD1. Consistent with previous work (Nicolas et al., 2006) we find that the two S. pombe proteins, which we name Swm1 and Swm2 (after SWIRM1 and SWIRM2), associate together in a complex. We find that this complex specifically demethylates lysine 9 in histone H3 (H3K9) to up- and down-regulate expression of different genes. Using chromatin-immunoprecipitation, to isolate fragments of chromatin containing either H3K4me2 or H3K9me2, and DNA microarray analysis (ChIP-chip), we have studied genome-wide changes in patterns of histone methylation, and their correlation with gene expression, upon deletion of the swm1+ gene. Using hyper-geometric probability comparisons we uncover links between lysine specific demethylases, the histone deacetylase Clr6, and the chromatin remodeller Hrp1. Keywords: chip on chip Genome-wide studies of histone demethylation catalysed by the fission yeast SWIRM and polyamine oxidase domain homologues of mammalian LSD1