Expression, Purification, Characterization and Cellular Uptake of MeCP2 Variants.

The transcriptional regulator Methyl-CpG-binding protein 2 (MeCP2) is an intrinsically disordered protein, mutations in which, are implicated in the onset of Rett Syndrome, a severe and debilitating neurodevelopmental disorder. Delivery of this protein fused to the cell-penetrating peptide TAT could allow for the intracellular replenishment of functional MeCP2 and hence potentially serve as a prospective Rett Syndrome therapy. This work outlines the expression, purification and characterization of various TAT-MeCP2 constructs as well as their full-length and shortened eGFP fusion variants. The latter two constructs were used for intracellular uptake studies with subsequent analysis via western blotting and live-cell imaging. All purified MeCP2 samples exhibited high degree of stability and very little aggregation propensity. Full length and minimal TAT-MeCP2-eGFP were found to efficiently transduce into human dermal and murine fibroblasts and localize to cell nuclei. These findings clearly support the utility of MeCP2-based protein replacement therapy as a potential Rett Syndrome treatment option.