Characterization of the DNA binding property of emerin

Emerin is an inner nuclear membrane protein, which is the gene product resp onsible for X-linked Emery-Dreifuss muscular dystrophy (X-EDMD). lit this s tudy we extracted emerin front mammalian cells and examined the DNA binding property by in vitro binding assay with double-strand DNA cellulose. We pr epared emerins from two sources; the native emerin in HeLa cells and the re combinant human emerin produced in COS7. These samples were incubated with DNA cellulose, and the bound proteins were directly eluted with salt-contai ning buffers. These elutants were subsequently analyzed by SDS-PAGE and wes tern blotting. The results showed that 1) both HeLa cell emerin and recombi nant COS7 emerin were recovered in the elutants of the binding assays, and 2) several other nuclear proteins were always co-isolated in the purificati on procedure of recombinant COS7 emeriti. These results suggest that emerin is tightly integrated in some protein "complex" with other nuclear compone nts and hinds DNA asa protein complex. In this study we demonstrated that e meriti directly or indirectly binds to DNA.