Mapping of the gypsy retrotransposon sequence is responsible for the EAST-dependent repression in the yellow gene model system of Drosophila melanogaster

Resumo

The EAST protein is a component of nuclear matrix. In the interphase cells, EAST is localized in the extrachromosomal nuclear domain. Increased EAST concentration leads to a change in spatial chromatin structure. However, previously, it was not known whether this protein played any role in the regulation of transcription. This study examines the mechanism of the EAST protein effect on the yellow gene transcription. It was demonstrated that the EAST-dependent repression observed in a model system of the yellow gene could occur not only in the presence of the Su(Hw) insulator sequence but also in the presence of the long terminal repeat sequence of the gypsy retrotransposon. In the LTR, a 92-bp sequence involved in the mechanism of EAST-dependent repression was detected. These results suggest that the found DNA motif is the place of the assembly of a protein complex, which functionally interacts with the EAST protein. This complex either independently suppresses the yellow gene expression in bristles or moves the transgene in the nuclear region with a high concentration of transcription repression factors.