Figure 7.

Overexpression of UBF1 is not sufficient to activate silenced rDNA. (A) Western blot analysis of NIH3T3 cell lines expressing rUBF1-MSCV or empty vector MSCV. (B) qChIP analysis of UBF binding to rDNA in cell lines in A. Samples were analyzed by qRT-PCR as described in Fig. 1 D (n = 3). (C) ChIP-CHOP assay of ChIP samples in B was performed as in Fig. 6 D (n = 3). (D) Nuclei from cells listed in A analyzed by psoralen cross-linking (left). The proportion of active versus inactive rDNA was quantitated (right; n = 5; **, P < 0.01). ENH, enhancer; ITS, internal transcribed spacer. Mean ± SEM (error bars).