Figure 4.

Pin1 associates with G1/S-phase RNAP IIO and with transcribing genes. (A) HeLa ChIP and NEs were prepared from cells released from a G1/S block at the times indicated. (Top panel) ChIP experiments were performed with anti-Pin1 antibodies, and products were amplified with primers for the β-actin gene at the promoter, coding, and poly(A) regions; for the cyclin D1 gene at the coding region; and for 28S RNA genes. Aliquots of the NEs were immunoprecipitated with anti-Pin1 antibody (@-Pin1 IP) or rabbit IgG (Mock). (Bottom panel) IPs were analyzed by Western blots probed with H14 antibodies. The input blot was also probed with 8WG16. (B) Similar ChIP and IP experiments were performed as in A, but with extracts prepared from cells released from M-phase arrest.