Fig. 3.

pRB is more heavily O-GlcNAc modified in G1 of the cell-cycle. pRB from pre-cleared lysates of HeLa S3 arrested in G1 with lovastatin or growing asynchronously was immunopurified. Equal amounts of pRB, as well as the antibody alone, were subjected to radioactive galactose capping of the O-GlcNAc modification via β-1,4-galactosyltransferase, separated by SDS–PAGE, and Western blotted with an anti-pRB antibody or visualized by autoradiography