Abstract: The present invention relates to polynucleotides comprising a first nucleic acid sequence for a chromatin element, which is capable of enhancing expression, and at least one second nucleic acid sequence comprising a curved origin motif. Furthermore, the invention relates to a host cell, a non-human transgenic organism, a vector and a kit comprising the aforementioned polynucleotide. Moreover, the invention relates to methods for expressing a polynucleotide of interest.