Fig. (1) (1A-K). HDAC2 localizes to the cytoplasm of terminally differentiating murine keratinocytes. (A) Representative high magnification image of Keratin-10 positive epidermal spinous cell layer. (B) Representative high magnification image of cytoplasmic HDAC2 sequestration in Keratin-10 positive epidermal spinous cell layer. (C) Representative low magnification image of E15 murine skin demonstrating HDAC2 cytoplasmic retention specifically in terminally differentiating keratinocytes. Note lack of HDAC2 immunoreactivity in basal cell layer and underlying dermal mesenchyme. (D) HDAC2 retains cytoplasmic localization in newborn P1 murine keratinocytes. (E) Cytoplasmic HDAC2 is observed in keratinizing E17 murine upper lip epidermis but not in non-keratinizing E17 tongue. (F) Terminally differentiating, HDAC2 positive keratinocytes specifically display robust nuclear histone acetylation. HDAC2 exists as a nuclear protein in (G) E12 murine embryonic neural cortex cells, (H) undifferentiated normal human keratinocytes (NHEK), and (I) primary human foreskin keratinocytes (HFKs). (J) The epithelial transcription factor p63 localizes strongly to the nucleus of all E17 epidermal cells. (K) HDAC3 is a ubiquitous nuclear Class I HDAC in all E17 epidermal and dermal cells.