TY - JOUR
T1 - Physical and functional interaction between ribosomal protein L11 and the tumor suppressor ARF
AU - Dai, Mu Shui
AU - Challagundla, Kishore B.
AU - Sun, Xiao Xin
AU - Palam, Lakshmi Reddy
AU - Zeng, Shelya X.
AU - Wek, Ronald C.
AU - Lu, Hua
PY - 2012/5/18
Y1 - 2012/5/18
N2 - The ARF tumor suppressor protein activates p53 in response to oncogenic stress, whereas ribosomal protein L11 induces p53 following ribosomal stress. Both proteins bind to central, albeit non-overlapping, regions of MDM2 and suppress MDM2 activity toward p53. However, it is not known whether the two pathways are functionally connected. Here we show that ARF directly binds to L11 in vitro and in cells, which then forms a complex with MDM2 and p53. L11 collaboratively enhances ARF-induced p53 transcriptional activity and cell cycle arrest. Supporting these results, knocking down L11 reduces ARF-mediated p53 accumulation and alleviates ARF-induced cell cycle arrest. Interestingly, overexpression of ARF increases the levels of ribosome-free L11 and enhances the interaction of L11 with MDM2 and p53. These results demonstrate that ARF activates p53, at least partly by induction of ribosomal stress, which results in L11 suppression of MDM2, and suggest that the ARFMDM2-p53 and the L11-MDM2-p53 pathways are functionally connected.
AB - The ARF tumor suppressor protein activates p53 in response to oncogenic stress, whereas ribosomal protein L11 induces p53 following ribosomal stress. Both proteins bind to central, albeit non-overlapping, regions of MDM2 and suppress MDM2 activity toward p53. However, it is not known whether the two pathways are functionally connected. Here we show that ARF directly binds to L11 in vitro and in cells, which then forms a complex with MDM2 and p53. L11 collaboratively enhances ARF-induced p53 transcriptional activity and cell cycle arrest. Supporting these results, knocking down L11 reduces ARF-mediated p53 accumulation and alleviates ARF-induced cell cycle arrest. Interestingly, overexpression of ARF increases the levels of ribosome-free L11 and enhances the interaction of L11 with MDM2 and p53. These results demonstrate that ARF activates p53, at least partly by induction of ribosomal stress, which results in L11 suppression of MDM2, and suggest that the ARFMDM2-p53 and the L11-MDM2-p53 pathways are functionally connected.
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U2 - 10.1074/jbc.M111.311902
DO - 10.1074/jbc.M111.311902
M3 - Article
C2 - 22467867
AN - SCOPUS:84861209820
SN - 0021-9258
VL - 287
SP - 17120
EP - 17129
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 21
ER -