GADD45A

This gene is a member of a group of genes, the GADD45 genes, whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents (mutagens). The DNA damage-induced transcription of this gene is mediated by both p53-dependent and -independent mechanisms. The protein encoded by this gene responds to environmental stresses by mediating activation of the p38/JNK pathway via MTK1/MEKK4 kinase.^[7]

The fact that expression of this gene is an indicator of DNA damage has been exploited to construct an in vitro test for mutagenicity, the GADD45a-GFP GreenScreen HC assay.^[8] This assay consists of a cell line which has been engineered so that expression of GADD45A will lead to expression of green fluorescent protein, which can easily be detected. To test a substance for mutagenicity, it is applied to these cells and fluorescence is measured.

GADD45A has been shown to interact with:

• AURKA,^[9]
• Cdk1,^{[10][11][12][13]}
• CCNB1,^[10][13]
• GADD45GIP1^[14]
• MAP3K4,^[15]
• P21,^[12][16] and
• PCNA.^{[12][17][18][19][20]}

• Gadd45