1. Figure 7. Schematic model of the regulation of YY1 by Aurora B at G2/M.
Kassardjian A, Rizkallah R, Riman S, Renfro SH, Alexander KE, et al. (2012) The Transcription Factor YY1 Is a Novel Substrate for Aurora B Kinase at G2/M Transition of the Cell Cycle. PLoS ONE 7(11): e doi: /journal.pone

2. Regulation of caspase 7 cleavage of YY1 by CK2α.
Sarah Riman et al. Mol. Cell. Biol. 2012;32:
Regulation of caspase 7 cleavage of YY1 by CK2α. The model represents how YY1, a caspase substrate, is protected from caspase 7 cleavage when it is phosphorylated at S118 by CK2α. S118 is a residue adjacent to the caspase 7 recognition site. Failure of YY1 to undergo caspase cleavage in response to apoptotic signals could contribute to tumorigenesis.

3. Figure 5. Threonine 39 phosphorylation on YY1 peaks at G2/M transition.
Rizkallah R, Alexander KE, Kassardjian A, Lüscher B, Hurt MM (2011) The Transcription Factor YY1 Is a Substrate for Polo-Like Kinase 1 at the G2/M Transition of the Cell Cycle. PLoS ONE 6(1): e doi: /journal.pone
Threonine 39 phosphorylation on YY1 peaks at G2/M transition.
Stable HeLa-Flag-YY1 cells were synchronized by double-thymidine block and then released. (A) Analysis of the cell-cycle progression of HeLa cells released after double-thymidine block using fluorescence-activated cell sorting. Cells were stained with propidium iodide and analyzed based on their DNA content. An asynchronous population of cells was used as a control. (B) Whole cell extracts were prepared from HeLa-Flag-YY1 cells collected at the indicated times after release from double-thymidine block. Total WCE were analyzed on a Western blot after SDS-PAGE separation, and probed with anti-Plk1, anti-Cyclin B1, and anti-YY1 antibodies. Flag-YY1 was immunoprecipitated from the extracts of each time point, and then analyzed on a Western blot using anti-pT39 and anti-YY1 antibodies.

4. Figure 4 Temporal correlation between phosphorylation of HpTGEKP and pH3S10. HeLa cells grown on coverslips were synchronized by double-thymidine block, released and collected 8–10 h after release. Cells were stained with DAP I (blue) and immunostained with α-HpTGEKP (red) and α-pH3S10 (green). Specific mitotic stage labeling was based on chromatin morphology. (Bar, 20 µM).
Published in: Raed Rizkallah; Karen E. Alexander; Myra M. Hurt; Cell Cycle  2011, 10,
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