siRNAs against p14ARF and TRIP12 were synthesized by Integrated DNA Technologies (Coralville, Iowa) using the following sequences 5′-CAUGGUGCGCAGGUUCUUGGUGACC-3′ and 5′-CCAGGAGCAACAACUGAAAUCUGCA-3′, respectively. The negative control (scrambled) siRNA was purchased from Ambion (Grand Island, NY).
Following primary antibodies were used in this research: rabbit monoclonal anti-p14ARF (clone EPR17878, ab185620) from Abcam (Cambridge, MA), mouse monoclonal anti-β-actin (clone AC-74) from Sigma (St. Louis, MO), mouse monoclonal anti-GFP from Vanderbilt Monoclonal Antibody Core (Nashville, TN), rabbit polyclonal anti-beclin-1 (#3738), anti-LC3B (#2775) from Cell Signaling (Danvers, MA), rabbit polyclonal anti-TRIP12 (A301-814A) and anti-MKRN1 (A300-990A) from Bethyl Laboratories (Montgomery, TX), rabbit polyclonal SIVA1 (A01) from Abnova (Walnut, CA). The secondary antibodies used were HRP-conjugated anti-mouse IgG from Promega and anti-rabbit IgG from Cell Signaling.
Proteasomal inhibitor MG132 was purchased from EMD Millipore (Burlington, MA). Cycloheximide, bafilomycin A, pepstatin A and E-64d were all from Sigma.