CYCA-Luc accumulates in response to S-phase blockage, and is degraded via the ubiquitin-proteasome pathway in HeLa-CYCA-Luc cells.

<p>(<b>A</b>) After treatment with 5 µg/mL HCPT for 48 h, HeLa-CYCA-Luc cells were analyzed for DNA content by FACS after propidium iodide staining or were lysed. (<b>B, C</b>) Cell extracts were analyzed by immunoblotting (<b>B</b>) or assayed for luciferase activity (<b>C</b>). After treatment with 12 µmol MG132 for 15 h, HeLa-CYCA-Luc cells were lysed, and cell lysates were analyzed by immunoblotting (<b>D</b>) or assayed for luciferase activity (<b>E</b>). For normalization of luciferase or CYCA-Luc activity, the signal for untreated cells was set to 1. This experiment was repeated three times (n = 3). Error bars indicate standard error; *, p<0.05 compared with PBS.</p>