Ubiquitinated YY1 physically interacts with HDAC3 in the nuclei of rat
hippocampal cells; however, the interaction is markedly reduced after neuronal
depolarization. A, HDAC1, HDAC2, and HDAC3 are expressed in cell
nuclei of the rat hippocampal cells, and their expression is modified by PTZ
treatment. Equal amounts (20 μg) of nuclear cell lysates obtained from the
unstimulated (-PTZ) as well as from the PTZ-stimulated (2 h;
+PTZ) rat hippocampi were analyzed by Western blot with antibodies
against anti-HDAC1, -2, and -3. As a loading control, results of Western blot
analysis for histone H3 are shown. B, YY1 physically interacts with
HDACs in the nuclei of the rat hippocampal cells. Equal amounts (300 μg) of
nuclear cell lysates obtained from the unstimulated (-PTZ) as well as
from the PTZ-stimulated (2 h; +PTZ) rat hippocampi were
immunoprecipitated (IPα) with anti-HDAC1, anti-HDAC2, or
anti-HDAC3 antibody and analyzed for YY1 expression by Western blot. As a
positive control, protein nuclear cell lysate obtained from the unstimulated
hippocampi has been used (resolved in the input lane). The unmodified
YY1 and ubiquitinated YY1 (uYY1) are indicated. C, after
PTZ-evoked neuronal activation, an expression of the ubiquitinated form of YY1
is diminished in cell nuclei of the rat hippocampus. Equal amounts of nuclear
cell lysates obtained from the unstimulated (-PTZ) as well as from
the PTZ-stimulated (2 h; +PTZ) rat hippocampi were immunoprecipitated
with anti-YY1 or control (isotype) antibody and analyzed for a ubiquitin
expression by Western blot. As a positive control, protein nuclear cell
lysates obtained from the unstimulated hippocampi have been used. Please note
that the intensity of IgG bands reflects similar loading of immunoprecipitated
samples. The ubiquitinated YY1 (uYY1) and IgG heavy chain bands are
indicated. D, interaction of HDAC3 with ubiquitinated YY1 is neuronal
activity-dependent in cell nuclei of the rat hippocampus. Equal amounts (300
μg) of nuclear cell lysates obtained from the unstimulated (-PTZ)
as well as from the PTZ-stimulated (2 h; +PTZ) rat hippocampi were
immunoprecipitated with anti-HDAC3 or control (isotype) antibody and analyzed
by Western blot for ubiquitin. As a positive control, 20% of protein nuclear
cell lysate immunoprecipitated with anti-YY1 antibody from the unstimulated
hippocampi has been used. The ubiquitinated YY1 (uYY1) is indicated.
In the input lane, 30 μg of hippocampal nuclear proteins has been
resolved.