Figure 1. CSA localizes to nucleoli and CSA mutation impairs rDNA transcription. (A) Immunofluorescence stainings with anti-HA and CSA antibody showing CSA in green and nucleolin in red in HA-CSA reconstituted CS3BE cells before and after proteasomal inhibition by MG-132. (B) QPCR analysis of the 47S precursor rRNA and the gene internal 5.8S/ internal transcribed spacer expression in CS3BE cells and CS3BE cells reconstituted with HA-tagged CSA. (C) Inhibition of CSA expression reduces rRNA transcription. QPCR detection of CSA expression and the 47S precursor rRNA expression after anti-CSA shRNA transfection and antibiotic selection in secondary fibroblasts. Values are normalized against RPL13 expression and the respective IgG controls. Values are mean ± s.e.m. of 3 independent experiments. (*P > 0.05; **P > 0.01; ***P > 0.001)