CDK13, a Kinase Involved in Pre-mRNA Splicing, Is a Component of the Perinucleolar Compartment
Fig 8
Increased CDK13 complexes expression decreases PNC prevalence.
(A) GFP-tagged cyclins were expressed with or without HA-CDK13 in HeLa cells and the level of protein expression was controlled by GFP fluorescence or immunofluorescence. PNC prevalence was measured by immunofluorescence labelling with anti-PTB antibodies. Percentages (± SD) of transfected (GFP-positive) and non-transfected (nt) cells containing nuclear PTB-positive dots were evaluated by counting for each condition 500 cultured cells in three different transfection experiments. In those experiments, 30% of non-transfected HeLa cells were PTB-positive. **P<0.001. (B) HeLa cells were treated with (or without) siRNAs targeting CDK13. SiRNA2 only faintly diminished CDK13 expression levels and did not significantly altered PNC prevalence. In contrast, siRNA5 strongly altered CDK13 expression, leading to a significant decrease in PNC prevalence. In this set of experiments, 50% of control cells (w/o siRNA) were PTB-positive. *P<0,05.