Coexpression of PKCδ inhibits Bmx-induced DNA binding of Stat1. (A) Bmx (3 μg) and Stat1α (4 μg) expression vectors were transfected into COS cells together with expression vectors for the indicated PKC isoforms (4 μg), as shown. Cell lysates were analyzed in the mobility shift assay using 32P-labeled IRF-1 GAS oligonucleotide. First lane shows the 32P-labeled GAS oligonucleotide without cell lysate. Shown in the lower panel is an immunoblot from total cell lysates electrophoresed in 7.5% SDS-PAGE blotted for Stat1 using anti-HA antibodies. (B) The dose dependence of PKCδ inhibition of Stat1 DNA binding was evaluated by cotransfecting COS cells with expression vectors for Bmx (3 μg) and Stat1α (4 μg) and the indicated amounts of either PKCβ1 or PKCδ vectors. Cell lysates were analyzed in the mobility shift assay using 32P-labeled IRF-1 GAS oligonucleotide. Shown in the lower panel is an immunoblot from total cell lysates electrophoresed in 7.5% SDS-PAGE blotted for Stat1 using anti-HA antibodies.
