Expression of Drosophila IntS1 and IntS12 is interdependent, and stability of IntS1 requires an intact IntS12 microdomain.
A, Western blot analysis of endogenous integrator subunit expression from S2 cells treated with various dsRNA targeting IntSs. An ∼60-kDa cross-reacting band with anti-IntS1 polyclonal antibodies is used as the loading control (Con.). B, Western blot analysis of endogenous IntS1 expression in S2 cells stably expressing FLAG-tagged IntS12* proteins containing mutations within the IntS12 microdomain. An ∼130-kDa cross-reacting band with anti-IntS1 polyclonal antibodies is used as the loading control. Resc., rescue plasmid; VA, vector alone.