Active dissociation of the fluorescent dye Hoechst 33342 from DNA in a living cell: Who could do it?

It is assumed that DNA in mammalian cells is a dynamic conformationally uns table system. This instability provides the cell with a mechanism for disso ciating a large number of substances that bind tightly but not covalently t o DNA. Among these is the fluorescent dye Hoechst 33342, which binds to DNA in the minor groove. We have selected cell lines with a high capability fo r active dissociation of Hoechst 33342. Comparative protein analysis of the se lines by means of two-dimensional (2-D) electrophoresis was performed. C ell and nuclear proteins were analyzed from these and normal strains. A few proteins with significantly changed quantities have been found. The prelim inary search of the 2-D database allowed us to identity some known and unkn own cellular proteins that could participate in active dissociation of the dye from DNA.