FLASH结合早幼粒细胞白血病蛋白Ⅳ并增强p53的SUMO修饰  

FLASH Interacts with Promyelocytic Leukemia Protein Ⅳ(PML Ⅳ)and Enhances the SUMOylation of p53

作　　者：王梦妮 熊真真 王之盈 吴建华 石晓钟 WANG Meng-Ni;XIONG Zhen-Zhen;WANG Zhi-Ying;WU Jian-Hua;SHI Xiao-Zhong(School of Biology and Biological Engineering,South China University of Technology,Guangzhou 510006,China;School of Basic Medical Sciences,Jiangxi Medical College,Nanchang University,Nanchang 330031,China)

机构地区：[1]华南理工大学生物科学与工程学院生物技术系,广州510006 [2]南昌大学医学部基础医学院生理系,南昌330031

出　　处：《中国生物化学与分子生物学报》2024年第10期1426-1440,共15页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金项目(No.31771449)资助。

摘　　要：FLASH/CASP8AP2为基因组中一个独特的基因,参与多个细胞调控过程,包括细胞凋亡、组蛋白基因pre-mRNA的加工、转录调控以及细胞周期进程等。临床医学研究表明,FLASH是急性淋巴细胞白血病的一种预后标志物,还是多种癌细胞存活的关键因子。因此,对FLASH功能的深入研究有望为相关疾病治疗提供新的视角。我们先前鉴定FLASH为p53的结合因子,并发现其能够增强p53的转录活性。在此基础上,本文阐述了FLASH和p53相互作用的分子机制。研究结果表明,p53 K386突变显著降低其与FLASH(aa 51~200)和FLASH-SIM(aa 1534~1806)的结合强度。然而,GST沉降分析仅能检测到SUMO与FLASH-SIM而不是FLASH(aa 51~200)之间的相互作用。在细胞中过量表达FLASH增强了整体性SUMO1修饰以及p53的SUMO1修饰,这可能是FLASH增强p53转录活性的一种作用机制。由于PML NB为细胞内SUMO的亚细胞反应器,而PMLⅣ亚型能够特异性地增强p53的SUMO修饰,我们在此分析了FLASH与PMLⅣ之间的相互作用,并鉴定了二者相互作用的结构域基础:FLASH-N3A(aa 501~802)和FLASH-C2(aa 1807~1981)均能与PMLⅣ(aa 228~633)结合。进一步的研究显示,PMLⅣ能够增强FLASH调控的整体性SUMO修饰和p53的SUMO修饰,即二者在功能上存在协同性。FLASH与肿瘤抑制因子p53和PMLⅣ之间的相互作用,丰富了对其功能的认识,有望揭示FLASH在肿瘤发生过程中的作用机制,为癌症的诊断和治疗提供新的思路。As a unique gene in the genome,FLASH(FADD-like interleukin-1β-converting enzyme associated huge protein)/CASP8AP 2 is involved in multiple cellular processes,including apoptosis,histone gene pre-mRNA processing,transcriptional regulation,and cell cycle progression.Clinical studies have shown that FLASH is a valuable prognostic marker for acute lymphoblastic leukemia,and a crucial factor for the survival of various cancer cells.Therefore,in-depth research into the function of FLASH may offer new perspectives for the treatment of related diseases.Our previous research identified FLASH as a binding partner of p53,demonstrating that FLASH enhances the transcriptional activity of p53.Here we further investigate the molecular mechanisms of the interaction between FLASH and p53,revealing that the p53-K386R mutation(SUMOylation residue)attenuated its interaction with FLASH(aa 51-200)and FLASH-SIM(SUMO-interacting motif)(aa 1534-1806)significantly.However,SUMO can bind to FLASH-SIM directly,instead of FLASH(aa 51-200).Subsequent research shows that overexpression of FLASH in cells enhances global SUMO1 conjugation and p53-SUMO1 conjugation,therefore providing a plausible explanation for the underlying mechanism of FLASH enhancing the transcriptional activity of p53.Since promyelocytic leukemia protein nuclear body(PML NB)serves as subcellular reactors for SUMO conjugation within the cell,and the PML Ⅳ isoform can specifically enhance the SUMO modification of p53,we have investigated the interaction between FLASH and PML Ⅳ,and elucidated the structural basis of their interaction:both FLASH-N3A(501-802)and FLASH-C2(1807-1981)bind to PML Ⅳ(aa 228-633).Further investigations reveal that they can synergistically enhance global SUMO1 modification as well as SUMO1 modification of p53.The interaction between FLASH and tumor suppressors p53 or PML Ⅳ enriches our understanding of its function and reveals the potential mechanism of FLASH in tumor development,therefore offering novel insights into cancer diagnosis and treatm

关 键 词：FADD样白细胞介素1β转化酶相关巨蛋白 P53 小泛素样修饰 早幼粒细胞白血病蛋白Ⅳ 

分 类 号：Q291[生物学—细胞生物学]