Y23A, Y24A, R34A, and C151A mutants affect
HDAC1 deacetylase activity
but not protein association. (A) Wild-type or mutant proteins were
expressed in T-Ag Jurkat cells as FLAG-tagged fusion proteins, immunoprecipitated
with anti-FLAG-agarose beads, and tested for catalytic activity using
an in vitro fluorescence assay (histogram) or separated on SDS-PAGE
and probed with anti-FLAG antibody (gel image). The histogram shows
the mean percent of at least four independent trials, which were normalized
to wild-type deacetylase activity (set to 100%). The standard error
is shown as error bars (Table S1). (B).
Immunoprecipitates of wild type and alanine mutants in panel A were
further probed with anti-FLAG, anti-RbAp48, or anti-mSin3A antibodies
to assess protein association.