Vitamin D controls the expression o

Vitamin D controls the expression of Nrf2 [28,29], which is a
redox-sensitive transcription factor that activates many genes that
encode antioxidant and detoxifying enzymes [30e32] (Fig. 2). The
transcriptional activity of Nrf-2 is regulated by a number of mechanisms that determines its nuclear import/export balance and its
degradation [33e35] (Fig. 3). In the absence of cell stress and reactive
oxygen species (ROS), the Nrf2 binds to Kelch-like ECH-associated
protein 1 (Keap1), which represses Nrf2 activity and is associated
with the ubiquitin ligase Cullin 3 that ubiquitinates Nrf2 resulting in
its degradation by the proteasome.