TY - JOUR
T1 - The promyelocytic leukaemia protein tumour suppressor functions as a transcriptional regulator of p63
AU - Bernassola, Francesca
AU - Oberst, Andrew
AU - Melino, Gerry
AU - Pandolfi, Pier Paolo
PY - 2005/10/20
Y1 - 2005/10/20
N2 - p63 plays unique developmental roles in epidermal morphogenesis, despite its structural similarity with p53. The p63 gene has two distinct promoters, coding for proteins containing an N-terminal transactivation domain (TA isoforms) and for proteins lacking this region (ΔN isoforms). The full-length transcriptionally active TAp63 isoforms are capable of transactivating the majority of the p53 target promoters thus inducing cell cycle arrest and apoptosis. On the contrary, the ΔNp63 isoforms seem to counteract the transactivation activities of p53 and TAp63 proteins, thus possibly conferring a proliferative advantage to cancer cells. However, the molecular mechanisms controlling the transcriptional activity of p63 remain largely unclear. Here we present data indicating that (i) the promyelocytic leukaemia protein (PML) physically interacts with p63, (ii) p63 is localized into the PML nuclear-bodies (PML-NBs) in vivo, and (iii) PML regulates p63 transcriptional activity. We show that the interaction of p63 with PML increases the levels of p63 in cultured cells as well as its ability to transactivate the p53-responsive elements of the GADD45, p21 and bax promoters. These data are consistent with a general role for PML as a functional modulator of all the p53 family members. Our findings strengthen the relevance of the cross talk between PML and the p53 family members, imply a new tumour suppressive function of PML and unveil a possible role for PML in epidermal morphogenesis and differentiation.
AB - p63 plays unique developmental roles in epidermal morphogenesis, despite its structural similarity with p53. The p63 gene has two distinct promoters, coding for proteins containing an N-terminal transactivation domain (TA isoforms) and for proteins lacking this region (ΔN isoforms). The full-length transcriptionally active TAp63 isoforms are capable of transactivating the majority of the p53 target promoters thus inducing cell cycle arrest and apoptosis. On the contrary, the ΔNp63 isoforms seem to counteract the transactivation activities of p53 and TAp63 proteins, thus possibly conferring a proliferative advantage to cancer cells. However, the molecular mechanisms controlling the transcriptional activity of p63 remain largely unclear. Here we present data indicating that (i) the promyelocytic leukaemia protein (PML) physically interacts with p63, (ii) p63 is localized into the PML nuclear-bodies (PML-NBs) in vivo, and (iii) PML regulates p63 transcriptional activity. We show that the interaction of p63 with PML increases the levels of p63 in cultured cells as well as its ability to transactivate the p53-responsive elements of the GADD45, p21 and bax promoters. These data are consistent with a general role for PML as a functional modulator of all the p53 family members. Our findings strengthen the relevance of the cross talk between PML and the p53 family members, imply a new tumour suppressive function of PML and unveil a possible role for PML in epidermal morphogenesis and differentiation.
KW - Nuclear body
KW - p63
KW - PML
KW - Transcription
UR - http://www.scopus.com/inward/record.url?scp=27144507300&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27144507300&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1208843
DO - 10.1038/sj.onc.1208843
M3 - Article
C2 - 16007146
AN - SCOPUS:27144507300
VL - 24
SP - 6982
EP - 6986
JO - Oncogene
JF - Oncogene
SN - 0950-9232
IS - 46
ER -