BACKGROUND: GADD45 is a multifunctional protein involved in DNA repair and in cell cycle checkpoint control. p53 plays an important role in regulating DNA repair and in response to UVB in keratinocytes. OBJECTIVE: GADD45 and p53 expression was examined and compared at the mRNA and protein level after exposure to UV irradiation. METHODS: Human keratinocytes were exposed to increasing doses of UVB, and an RNA protection assay and a Western blot analysis were performed. RESULTS: The RNase protection assays using human keratinocytes showed that GADD45 mRNA increases after 4 h and remains elevated for 24 h in cells irradiated at 100, 300, or 600 J/m2 UVB. The level of GADD45 protein increases after 8 h and remains elevated for 48 h, with maximal induction at 300 J/m2. p53 mRNA did not rise in concert with GADD45 at any dose used, and p53 protein was not up-regulated at the lower dose of 100 J/m2. CONCLUSION: GADD45 is regulated in both a p53-dependent and a p53-independent manner in keratinocytes after UV exposure.
BACKGROUND:GADD45 is a multifunctional protein involved in DNA repair and in cell cycle checkpoint control. p53 plays an important role in regulating DNA repair and in response to UVB in keratinocytes. OBJECTIVE:GADD45 and p53 expression was examined and compared at the mRNA and protein level after exposure to UV irradiation. METHODS:Human keratinocytes were exposed to increasing doses of UVB, and an RNA protection assay and a Western blot analysis were performed. RESULTS: The RNase protection assays using human keratinocytes showed that GADD45 mRNA increases after 4 h and remains elevated for 24 h in cells irradiated at 100, 300, or 600 J/m2 UVB. The level of GADD45 protein increases after 8 h and remains elevated for 48 h, with maximal induction at 300 J/m2. p53 mRNA did not rise in concert with GADD45 at any dose used, and p53 protein was not up-regulated at the lower dose of 100 J/m2. CONCLUSION:GADD45 is regulated in both a p53-dependent and a p53-independent manner in keratinocytes after UV exposure.
Authors: Alexey A Moskalev; Zeljka Smit-McBride; Mikhail V Shaposhnikov; Ekaterina N Plyusnina; Alex Zhavoronkov; Arie Budovsky; Robi Tacutu; Vadim E Fraifeld Journal: Ageing Res Rev Date: 2011-10-05 Impact factor: 10.895
Authors: Amanda S MacLeod; Ross Rudolph; Ross Corriden; Ivan Ye; Olivia Garijo; Wendy L Havran Journal: J Immunol Date: 2014-05-07 Impact factor: 5.422