Establishing the molecular function of the zinc finger domain of NEMO in DNA damage-dependent NF-&kappaB activation

Owing to the functional importance of the transcription factor NF-kappaB in numerous clinically significant contexts, intense interest has focused on characterizing the molecular events that lead to activation of NF-kappaB in response to many different stimuli. NF-kappaB Essential Modulator (NEMO) is centrally important for many pathways leading to NF-kappaB activation, including in response to DNA damaging agents that generate double strand breaks (DSB) in the nucleus. The goal of this project was to understand the mechanistic basis for the requirement of the zinc finger (ZF) domain of NEMO for NF-kappaB activation in response to genotoxic stress.Using a somatic genetic reconstitution approach, I uncovered a new function of the ZF as a novel histone H2B binding domain that appears to be critical for NF-kappaB activation in response to DNA damage. Subsequent work utilized native electrophoretic techniques to establish a new assay to monitor the presence of a specific fraction of "free" NEMO that appears to be required for NF-kappaB activation following genotoxic stress. These findings extend our knowledge of the signal transduction events following genotoxic stress and provide new insight into the functional significance of NEMO in the DNA damage pathway of NF-kappaB activation.