library_construction_protocol: After treatment cells were crosslinked with 0.15% formaldehyde on ice for 10 min with slow agitation. Crosslinking was stopped with 37.5 mM glycine. Cells were washed with PBS and lysed with 100 mM KCl, 20 mM Tris-HCl pH 8, 1.5 mM MgCl2, 1.5% (v/v) NP-40, 2 mM DTT supplemented with protease inhibitor. After lysis, lysate was clarified. Total RNA from 10% of the lysate was extracted by hot acid phenol extraction. TruSeq mRNA stranded Illumina