Figure 6. PTRF nuclear localization is regulated by its nuclear export signals and other post-translational modifications.
(A) Schematic illustration of nuclear export signals (NES) and nuclear localization signal (NLS) motifs in mouse PTRF protein. (B) NES deleted PTRF constructs and wild type control were transfected to HEK293 cells. The nuclear and cytoplasmic fractions were separated on SDS-PAGE following by immunoblot using indicated antibodies. (C) Basal and nutrients/insulin-stimulated 47S levels were measured from empty vector controls (C), wild type (WT) and NES motif deleted PTRF cDNA constructs transfected PTRF null MEFs cells. (D and E) Total rat adipocyte lysate were immunoprecipitated by IgG, or PTRF or ubiquitin (Ui) followed by SDS-PAGE and blotted with indicated antibodies. (F) A scheme of 8 designed PTRF fragment mutants (C1-4, N1-4). (G) Whole cell lysates from Wild type HEK293 cells transfected by (WT) and 8 PTRF fragment mutants were immunoprecipitated by myc-tag magnetic beads followed by immuno-blots with indicated antibodies.