NS1 upregulates expression of cyclin B1, CDK1, and p21, but not expression of ATM and CHK2.

<p>NS1-S1 and NS1^mTAD2-S1 cells were treated with Dox (5 μg/ml) and collected and lysed 72 h later. (A) Cell lysates were analyzed for expression of cyclin B1, phosphorylated CDK1 (CDK1(pY15) and CDK1(pT161), lower band [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006266#ppat.1006266.ref042" target="_blank">42</a>]), and total CDK1 by Western blotting. (B) Cell lysates were analyzed for expression of ATM(pS1981), ATM, CHK2, CHK2(pS33/35), and β-actin by Western blotting. (C) Cell lysates were analyzed for expression of p21 by Western blotting with an anti-p21 antibody. β-actin was used as a loading control. Untreated UT7/Epo-S1 (S1) cells, S1 cells treated with nocodazole (Noco), and S1 cells treated with hydroxyurea (HU) were used as controls.