The ChIP was performed with 20 min crosslinking in 1 % formaldehyde in PBS. Following chromatin shearing , 1-2µg antibody was used for immunoprecipitation overnight. The immunocomplexes were incubated 2 additional hours with protein A sepharose beads and subjected to washes. After reversing the cross-linking, the DNA was isolated by standart phenol-chloroform-isoamyl extraction procedure. ChIP-Seq libraries were prepared with MicroPlex Library Preparation Kit following the manufacturer's instructions.