Fig. 5. STAU1 protein regulates circSNX5 biogenesis dependent on its RNA-binding activity.

A Control and STAU1 shRNA were delivered into cells, and the protein and RNA expression of cells was analyzed by Western blot assay and RT-qPCR assay, respectively. GAPDH expression served as internal control for immunoblotting. B CircSNX5 PCR assays of indicated cells was performed, and resulting products were visualized by gel electrophoresis. PCR amplicons were annotated and quantified. C Subcellular fractionation experiments of indicated cells were performed, and circSNX5 RNA expression of fractions was analyzed by RT-qPCR assay. D Protein and RNA expression of control and STAU1 overexpressing cells were measured by Western blot assay and RT-qPCR analysis, respectively. GAPDH expression served as loading control for immunoblotting. E CircSNX5 expression of subcellular fractions in control and STAU1 overexpression cells was determined by RT-qPCR assays. F RNA-IP assay was performed with control and STAU1-specific antibodies, and precipitates was collected and subjected to RT-qPCR assay with the indicated primers. G, I Indicated STAU1 plasmids were delivered into the cells, and protein expression of transfectants was analyzed by Western blot assays. GAPDH expression served as internal control for immunoblotting. CircSNX5 PCR assays of the transfectants were performed and visualized by gel electrophoresis (H), and the PCR amplicons were noted and quantified.