Glucose deprivation activates Nrf1 through TADs other than the NST domain.

Abstract

<p>(<b>A</b>) Cells expressing wild-type Nrf1 were allowed to recover from transfection in fresh 5.5 mM-glucose-containing-medium for 8 h, and were thereafter cultured for a further 18 h in media containing 0, 1.1 or 25 mM glucose. The cell lysates were resolved by 4-12% LDS/NuPAGE, followed by immunoblotting with V5 antibodies to detect ectopic Nrf1 protein. (<b>B</b>) Increased activity of ectopic wild-type Nrf1 resulting from exposure to glucose deprivation (i.e. ‘no-glucose’) conditions (, p<0.001, n = 9) was determined by reporter gene assays, in which the transfected cells were allowed to recover for 8 h in medium containing 5.5 mM glucose before they were subjected to an additional 18-h culture in either glucose-free or 25-mM glucose medium. (C) Transactivation of an ARE-driven luciferase gene by Nrf1 or mutants, following 18-h no-glucose starvation, was calculated from three independent reporter gene assays. Significant increases in transactivation activity ($, p<0.05; , p<0.001, n = 9) and significant decreases (*, p<0.05; **, p<0.001, n = 9) are shown.</p