Research Paper Volume 14, Issue 15 pp 6128—6148

Figure 5. αB-crystallin inhibited CHK1 activation under the UVA irradiation. Both pEGFP-HLE and pEGFP-HαB-HLE cells (Mao et al., 2004) were grown to 90% confluence, then subjected to mock irradiation, 37.5 KJ/m2 and 75 KJ/m2 UVA irradiation, respectively. The irradiated cells were harvested for extraction of total proteins which were used for analysis of total CHK1 (T-CHK1, 54 kd), phosphorylated CHK1 at S-345 and β-Actin (loading control) levels (A) by Western blot analysis. Quantitative results of the T-CHK1 and p-CHK1-S345 against β-actin (loading control) levels in pEGFP-HLE cells and pEGFP-HαB-HLE cells (B) were analyzed by Image J software. Note that UVA induced significant upregulation of CHK1 activity (as reflected by phosphorylation at S345) in pEGFP-HLE cells. In contrast, in pEGFP-HαB-HLE cells, both total CHK1 and phosphorylated CHK1 at S345 were downregulated under UVA irradiation. N=3. NS, not significant. *p<0.05, ** p<0.01.