In order to obtain further information about the effect of KAP1 methylation on KAP1/KRAB zinc
finger protein interaction, the HEK293 cells were transfected with the expression vector for
Flag-ZNF224 in presence or absence of AdOx treatment and analyzed by IP-Western blot. We
observed that KAP1 co-precipitated with Flag-ZNF224 in a methylation-dependent fashion (Figure 2c). In
fact, the KAP1/ZNF224 interaction was enhanced by AdOx treatment (Figure 2c, lane 4 vs. lane 3).
This result indicates that arginine KAP1 methylation destabilizes of the association between KAP1 and
ZNF224, thus suggesting that the interaction between the corepressor KAP1 and ZNF224 could be
affected by PRMT5 catalytic activity.