Fig 2: The PRMT5/WDR77 complex shapes the transcriptome of MDA-MB-231 cells through methylation of ZNF326. Methylation of ZNF326 by the PRMT5/WDR77 complex is essential for Pol II transcription across A-T rich genes. Loss of PRMT5 or WDR77 leads to a loss of methylation of ZNF326 that results in slow progression of Pol II causing the inclusion of A-T rich exons in target genes. A subset of these transcripts is targeted for degradation thereby altering the shape of the transcriptome of the cell. (A) Represents the influence of PRMT5/WDR77 to coordinate the rate at which transcription may help determine splicing patterns, where, the absence of PRMT5/WDR77 (B) effects the rate and aberrant inclusion of exons.

Fig 3: ZNF326 is symmetrically dimethylated at R175 by the PRMT5/WDR77 complex (A). ZNF326 has two glycine-arginine rich motifs. Asterisk indicates R175 that was identified to be dimethylated (B). Immunoblots of immunoprecipitates showing symmetric dimethylation of ZNF326 (C). Representative tandem mass spectrum of the peptide GR(28.0314)GTPAYPESTFGSR {m/z:537.602 (+3). The fragment ion matching within 10 ppm are shown as either the B-ion (purple) or Y-ion (blue) series. The green dashed line indicates precursor m/z. The dotted lines in the fragmentation ladder sequence on the top the spectrum corresponds to the missing B-ion (purple) and Y-ion (blue) series (D). Mass Spectrometry analysis showing the relative abundance of random and dimethylated peptides in cells infected with sh Scrambled, sh WDR77 and sh PRMT5 and (E). Graphical representation of the same.