BRF1 mutations alter RNA polymerase III–dependent transcription and cause neurodevelopmental anomalies

In vitro transcription defects caused by BRF1 mutations in yeast. (Top) A representative gel of the in vitro transcription reaction using a nuclear extract harboring a deficient Brf1 protein (p.Trp107Arg, W107R) that is impaired in Pol III–dependent transcription. Addition of WT Brf1 rescues activity whereas the different Brf1 variants and the combinations present in the affected children show a defect in transcription. Data are presented as mean ± SD. A quantification is shown in the middle panel. (*) P < 0.01; (**) P < 0.0001. The lower panel shows a twelve times excess of the Brf1 protein amount used for this assay separated on an SDS gel.