IMPACT OF LAMIN A ON PPARγ-DNA BINDING

Abstract

This study investigated how the absence of lamin A, a key nuclear structural protein, affects the mobility and DNA-binding of the lipid-regulating receptor PPARγ. Using viral transduction, researchers expressed EGFP-tagged PPARγ in both wild-type and lamin A-knockout mouse adult fibroblasts. Fluorescence correlation spectroscopy (FCS) identified two distinct PPARγ populations: a fast, freely diffusing group and a slow, DNA-bound group. Treating the cells with the ligand rosiglitazone (RSG) significantly increased the slow, DNA-bound population and decreased overall diffusion constants in both cell types. This treatment also revealed that PPARγ preferentially binds to euchromatin over heterochromatin regions. Ultimately, the data demonstrated that while RSG strongly promotes PPARγ DNA-binding, the absence of lamin A has no significant impact on this binding activity.