Differential functions of LSD1 isoforms. (A) Calf thymus histones or HeLa mononucleosomes were incubated with purified LSD1 (0, 2, and 20 μg) with or without recombinant CoREST, followed by immunoblotting using specific antibodies or silver staining (LSD1 and histones) (top panel). Signal intensities were quantified and shown as relative values of corresponding untreated controls (bottom panel). (B) Whole-cell lysates were prepared from HEK293 cells transfected with expression vectors for LSD1 isoform (−/−) or (+/−), and subjected to immunoblotting with the indicated antibodies. Signal intensities were quantified and shown as relative values of corresponding mock transfectants. (C) LSD1 expression and activity in HSPCs (see “Results” for details).