1A6/DRIM bound rDNA promoter and interacted with UBF at the rDNA promoter.

<p>A. Chromatin immunoprecipitation (ChIP) was performed with antibodies directed against either 1A6/DRIM or UBF. Mouse IgG (mIgG) was used as an antibody control. A DNA fragment of the rDNA promoter sequence was amplified by PCR. DNA fragments from either the U6 or GAPDH promoter were amplified as controls. The PCR products were resolved on a 2% agarose gel and stained with EB. B. Whole cell lysate was extracted from U2OS cells. Immunoprecipitation was carried out with anti-1A6/DRIM antibody. Proteins from 1A6/DRIM specific immunoprecipitates were separated on SDS-PAGE and blotted onto PVDF membranes. The upper part of the blot was probed with anti-1A6/DRIM antibody and the lower part of the same blot was hybridized with anti-UBF antibody or anti-TAF_I110 antibody. C. Re-ChIP experiment was performed to confirm that 1A6/DRIM bound UBF at the rDNA promoter. ChIP was performed using an anti-1A6/DRIM antibody. Re-ChIP was carried out using either mouse IgG (mIgG) or an anti-UBF antibody. A DNA fragment of the rDNA promoter sequence was amplified by PCR. DNA fragments from either the U6 or GAPDH promoter were amplified as controls. The PCR products were resolved on a 2% agarose gel and stained with EB.