ATXN2 overexpression reduces the endogenous PAPB level. Top, HEK293T cells were transfected with plasmids encoding MYC-ATXN2(Q22) or MYC-ATXN2(Q79) proteins. Twenty-four hours post transfection, proteins were visualized with antibodies directed against the MYC-tag and PABP, respectively. Nuclei in all images presented were stained with Hoechst. Bars, 10 μm. Arrows indicate nontransfected cells. Bottom, Western blot analysis. HEK293T transiently overexpressing MYC-ATXN2(Q22) or MYC-ATXN2(Q79) proteins were lysed. The same amount of each protein lysate was separated by SDS-PAGE and transferred to a nitrocellulose membrane or stained with Coomassie to demonstrate equal loading of each lysate. Antibodies directed against ATXN2, PABP, and TIA-1 were used for visualization of proteins.