Fig. 1: ATRA induces the ubiquitin-independent proteasomal degradation of p11 in APL cell line, NB4.

a Immunoblot analysis of NB4 cells treated for 48 h with 1 µM ATRA alone or in combination with 2 µM lactacystin (LC) or 2 µM PYR-41. b Immunoprecipitation of p11 or IgG1 isotype control in NB4 cells treated for 24 h with 1 µM ATRA alone or in combination with 2 µM LC. Purified AIIt (0.25 µg) was used as a control. c Immunoprecipitation of p11 in PR9 cells treated for 48 h with 2 µM LC. Purified AIIt (0.25 µg) was used as a control. d Immunoprecipitation of p11 or IRS-1 in NB4 cells treated for 24 h with 1 µM ATRA alone, or in combination with 2 µM LC. Cell lysates were prepared and the level of the indicated proteins were examined by immunoblot analysis with β-actin used as a loading control. Data is expressed as the mean ± S.D. of three independent experiments. Statistical significance was determined using one-way ANOVA (with Tukey multiple comparisons), where **P < 0.01, ***P < 0.001, and ****P < 0.0001 are considered statistically significant