Luxton Hayley J, Barnouin Karin, Kelly Gavin, Hanrahan Sarah, Totty Nick, Neal David E, Whitaker Hayley C
Uro-Oncology Research Group, Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK.
Protein Analysis and Proteomics, Cancer Research UK London Research Institute, London WC2A 3LY, UK; Protein Analysis and Proteomics, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms, Potters Bar EN6 3LD, UK.
Mol Oncol. 2014 May;8(3):633-41. doi: 10.1016/j.molonc.2014.01.009. Epub 2014 Jan 24.
The pivotal role of LYRIC/AEG-1 in malignant transformation, tumourigenesis and chemo-resistance has previously been demonstrated in different cell types and sub-cellular compartments. The localisation of LYRIC/AEG-1 appears crucial to its function and is regulated by three lysine-rich nuclear localisation signal regions, one of which was previously demonstrated to be modified by ubiquitin. Here we show that mutation of LYRIC/AEG-1 at K486 and K491 results in a loss of ubiquitination. A K486/491R double mutant that is incapable of ubiquitination shows reduced binding to the NFκB subunit p65 or importin-β resulting in a distinctive peri-nuclear localisation of LYRIC/AEG-1. We also provide evidence to suggest that TOPORS, an E3 ligase that also regulates p53 modification may be responsible for LYRIC/AEG-1 ubiquitin modification. Overall we demonstrate that specific sites of LYRIC/AEG-1 ubiquitination are essential for regulating LYRIC/AEG-1 localisation and functionally interacting proteins.
LYRIC/AEG-1在恶性转化、肿瘤发生和化疗耐药中的关键作用先前已在不同细胞类型和亚细胞区室中得到证实。LYRIC/AEG-1的定位似乎对其功能至关重要，并且受三个富含赖氨酸的核定位信号区域调控，其中一个先前已被证明可被泛素修饰。在此我们表明，LYRIC/AEG-1在K486和K491处的突变导致泛素化缺失。一个无法进行泛素化的K486/491R双突变体显示出与NFκB亚基p65或输入蛋白-β的结合减少，导致LYRIC/AEG-1出现独特的核周定位。我们还提供证据表明，同样调节p53修饰的E3连接酶TOPORS可能负责LYRIC/AEG-1的泛素修饰。总体而言，我们证明了LYRIC/AEG-1泛素化的特定位点对于调节LYRIC/AEG-1的定位和功能相互作用蛋白至关重要。
