Western blot of wild type IRES element and its deletion mutants substantiate the efficiency of the PTB elements: A) Schematic representation of Di-cis constructs used for the Western blot analysis. pRE; control vector having RLuc as first cistron and EGFP as downstream cistron, pRE-IR; wild type IRES containing Di-cis construct, pRE-IRDel1; PPT1 deleted, pRE-IRDel2; PPT2 deleted and pRE-IRDel3; PPT1 and PPT2 deleted IRES construct. B) Western blot of the constructs transiently transfected into N2A cells. 30 μg of cytosolic total proteins were resolved by 10% SDS-PAGE. Immunodetection was done using anti-GFP (1:2000) as primary antibody and peroxidase labeled anti-mouse IgG (1:7,500) as secondary antibody. C) The detection of β-actin served as internal loading control.