Repression by Exile: Repositioning to Nuclear Lamina Represses Expression

Source: Reddy et al. (2008). Transcriptional repression mediated by repositioning of genes to the nuclear lamina. Nature 452:243-247.

The correlation between nuclear compartmentalization and gene expression is long known; however, we don't know whether the observed repression of transcription is a by-product of switching compartments or they simply co-occur for other reasons. This paper makes the case for the former; the authors design a construct that can be attached to nuclear membrane upon induction. The reporter set-up (shown below) involves a hygromycin resistance gene (Tk-hyg) as well as multiple copies of Lac operators (lacO) that constitute binding sites for the E. coli Lac repressor (LacI). A GFP-LacI-ΔEMD which is tethered to the nuclear membrane through ΔEMD can be induced by IPTG to recruite lacO sites on the reporter. The localization of the reporter can be simultaneouly monitored using a GFP-LacI fusion.

Using this set-up the authors make the case for a general repression mechanism through membrane tethering. They also employ other methods (e.g. FISH and DamID) to further validate their results which I don't get into.