Takahashi Yuki, Lallemand-Breitenbach Valérie, Zhu Jun, de Thé Hugues
CNRS UPR 9051, laboratoire associé No 11 du comité de Paris de la Ligue contre le Cancer, affilié à l'université de Paris VII. Hôpital Saint-Louis, centre Hayem, 1, av. C. Vellefaux 75475 Paris Cedex 10, France.
Oncogene. 2004 Apr 12;23(16):2819-24. doi: 10.1038/sj.onc.1207533.
Promyelocytic leukaemia nuclear bodies (PML NBs) are structured protein complexes associated with the nuclear matrix. PML constitutes the scaffold component of NBs and recruits onto these domains a striking variety of proteins, many of which are involved in apoptosis control. Several reports have directly implicated PML in apoptosis and senescence, but the mechanisms by which these are conveyed are still largely unsettled. Recruitment of partner proteins onto NBs is regulated by PML sumolation, a specific post-translational modification also found in many NB-associated proteins. Among these, several are implicated in transcription repression or activation, like the transcriptional repressor Daxx or the transcriptional activator P53. Whether NBs constitute platforms where active sites of enzymatic modifications are carried out, as suggested for P53, sites of intranuclear protein sequestration, as proposed for Daxx or organelles specialized in catabolism, is still debated. A variety of stress-related signalling pathways dramatically modulate the formation of PML NBs, which may provide a clue as to their physiological function.
早幼粒细胞白血病核体（PML NBs）是与核基质相关的结构化蛋白复合物。PML构成了核体的支架成分，并在这些结构域上招募了大量不同的蛋白质，其中许多蛋白质都参与细胞凋亡调控。有几份报告直接表明PML与细胞凋亡和衰老有关，但其中的具体机制仍未完全明确。核体上伴侣蛋白的招募受PML的SUMO化调控，SUMO化是一种在许多与核体相关的蛋白质中也能发现的特定翻译后修饰。其中，有几种蛋白质与转录抑制或激活有关，比如转录抑制因子Daxx或转录激活因子P53。核体是否如P53那样构成进行酶促修饰活性位点的平台，如Daxx所提出的那样是核内蛋白质隔离的位点，或者是专门进行分解代谢的细胞器，目前仍存在争议。多种与应激相关的信号通路能显著调节PML NBs的形成，这可能为其生理功能提供线索。
