SP13 The role of the transcription factor 'Myc interacting zinc finger protein 1' (Miz-1) in response to genotoxic stress

Project leader: Christian Kosan

Background and previous work
Mammalian cells respond to genotoxic stress like DNA damage by the induction of cell cycle arrest or apoptosis, regulated by the tumour-suppressor p53. The cell fate decision induced by p53 is thought to be mediated by the extent of damaged DNA. However, how cells make the decision between cell cycle arrest and apoptosis is not fully resolved yet. We and others have previously shown that Miz-1 and the Miz-1/Myc complex control the p53 response upon genotoxic stress and are key links in this decision.

Specific aims
We will analyse the role of Miz-1 in cellular response to dose- and time-dependent genotoxic stress. In this context we will focus on 2 Aims: (1) The role of Miz-1 in the response to genotoxic stress and the Miz-1-dependent regulation of p53 function. Miz-1-/- mice will be subjected to different amounts of γ-radiation or isolated lymphocytes will be treated with increasing levels of DNA damaging agents such as the alkylating agent MNNG or etoposide. We will test for damaged DNA by measuring phosphorylated H2AX (γH2AX), determine cellular ROS levels and the expression of p53 target genes in the presence and absence of Miz-1 by ChIP-Seq and microarray experiments. (2) The role of Miz-1 and the Myc/Miz-1 complex in metabolic changes and regulation of autophagy after dose- and time-dependent DNA damage response (DDR). We will analyse Miz-1 function in regulation of AMPK and mTOR pathways during metabolic reprogramming. We will monitor the metabolic response to DDR and analyse the role of Miz-1 in the regulation of autophagy and the autophagic flux.
Taken together, our findings will provide new insights into cell fate decisions induced by p53 and its role in adaptive stress-induced persistence after DDR.