E. Total cell extracts were prepared from U2OS cells treated with PCM1 siRNA and transfected with RNAi-resistant EGFP-PCM1-WT*. Cells were cultured asynchronously (As) or arrested in G1, G2 or M phase, followed by immunoprecipitation with an anti-GFP antibodies. Pulled down samples were immunoblotted with the indicated antibodies. 