Figure 2.

Cell cycle-dependent phosphorylations on TAFs. Quantitative mass spectra of highly cell cycle-regulated phosphorylations on TAFs. Peak pairs representing isotopic labeled phosphopeptides derived from asynchronous and cell cycle blocked cells are indicated. Peaks labeled * are derived from isotopic labeled arginine-to-proline conversion, and should be added to the 'heavy' peaks for quantification. Shown are G2/M-induced phosphorylations on TAF1 (A), TAF1D (C), and TAF7 (D); G1/S-induced dephosphorylation on TAF3 (E). (B) Cell cycle-independent phosphorylation on TAF3. All phosphorylations were quantified after correction for protein levels (see Table 1).