HP1α and HP1β, but not HP1γ, coprecipitate with MyoD in
myoblasts. Nuclear extracts from growing myoblasts were used for
immunoprecipitation with antibodies raised against MyoD, Suv39h1, or control
beads (A) or against HP1α, HP1β, HP1γ, or normal
mouse IgG as a negative control (B). The resulting precipitates were
then subjected to Western blotting (immunoblot, IB) analysis for the
presence of Suv39h1, MyoD, HP1α, HP1β, and HP1γ as indicated
in A and B. Total input lysate was loaded in B to
show that HP1γ is present in the inputs, even if it is not present in
the IP. Lower panel of B, the faint signal obtained with
anti-HP1 Western blotting in the control IgG IP corresponds to IgG light chain
(noise).