Introductory paragraphGATA binding protein 3 (GATA3) has traditionally been regarded as a lineage-specific transcription factor that drives the differentiation of CD4+ T helper (Th) 2 cells. However, increasing evidence shows that GATA3 is involved in a myriad of processes such as immune regulation, proliferation and maintenance in other T cell and non-T cell lineages. We show here a previously unknown mechanism utilized by CD4+ T cells to increase mitochondrial mass in response to DNA damage through the binding of GATA3, AMP-activated protein kinase (AMPK), peroxisome-proliferator-activated receptor {gamma} co-activator-1 (PGC1), nuclear factor erythroid 2-related factor 2 (NRF2) and superoxide dismutase 3 (SOD3) to the DNA damage repair (DDR) component ATR. These findings extend the pleotropic nature of GATA3 and highlight the potential for GATA3-targeted cell manipulation for clinical interventions.