CPNE5对细胞凋亡的作用与机制研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
Copines蛋白家族是近期发现的一类进化保守的Ca2+依赖性磷脂结合蛋白,该家族蛋白有两个保守结构域:N端两个C2 domain,是结合钙和磷脂的部位,已知蛋白激酶C、磷脂酶C和突触结合蛋白等也有该结构域;C端的A domain,类似于整合素(integrin)中的A domain,具有蛋白质相互作用位点,是结合靶蛋白的结构域。CPNE5定位于第6号染色体的6p21.1基因座,含一个1782bp的开放阅读框,编码593个氨基酸的蛋白。本研究主要围绕CPNE5对TNF-a诱导的NF-kB转录激活活性的影响及其作用机制,以及CPNE5在细胞凋亡方面的作用进行了研究。
     在HEK293细胞中,TNF-a诱导CPNE5 mRNA表达显著上调。含有NF-κB调控靶序列的双荧光素酶报告基因实验结果表明,外源表达CPNE5能够抑制TNF-a诱导的NF-κB的转录激活活性。RT-PCR实验显示,过表达CPNE5抑制了NF-κB下游基因Bcl-2等在核酸水平的表达。为研究CPNE5保守区域A domain在CPNE5抑制NF-κB活性中的作用,我们构建了C2结构域缺失的AD(A domain)的GFP表达载体,发现AD-GFP融合蛋白在细胞内呈弥散表达,不同于CPNE5的定位。我们发现AD的高表达,可以显著地抑制TNF-a所诱导的NF-κB转录激活活性,且这种抑制作用与AD转染量具有剂量依赖性。这说明CPNE5的AD结构域在其抑制NF-κB转录激活中起到重要作用。
     在发现CPNE5可以显著抑制TNF-a对NF-κB的转录激活的基础上,我们进一步对抑制机制进行了研究。首先我们在HEK293细胞中建立了CPNE5的四环素诱导表达系统(Tet-on)。经过Zeocin筛选,我们挑取了7个pcDNATM 4/TO-CPNE5 T-Rex-293细胞克隆株。这些细胞株经四环素诱导12h~24h后,目的蛋白CPNE5有不同程度的表达。我们选取诱导表达量较高的细胞株,研究高表达CPNE5抑制NF-κB转录激活的机制。Western-blot结果显示,CPNE5高表达并不影响NF-κB亚单位p65的入核。细胞免疫荧光实验结果也验证了这一结果,正常HEK293细胞中,TNF-a刺激能诱导NF-κB的快速入核。Western blot实验和细胞免疫荧光实验结果均表明,外源高表达CPNE5没有阻止TNF-a诱导的NF-κB入核。这些结果表明,CPNE5不通过NF-κB出入核调节机制来抑制NF-κB的活性。凝胶阻滞实验结果表明,CPEN5过表达抑制了NF-κB的DNA结合活性。免疫共沉淀(co-IP)实验结果表明,外源表达的CPNE5和NF-κB(P65)有相互作用。为研究CPNE5是否如CPNE1一样可以剪切P65或P50,我们过表达CPNE5后再进行TNF-a处理,Westernblot检测未发现P65/P50有剪切体出现,这表明CPNE5没有如同家族的CPNE1一样诱导P65或P50的剪切。
     为研究外源表达CPNE5是否因为抑制了NF-κB的活性,从而抑制了TNF-a诱导的与细胞生存相关的信号通路,进而促进了TNF-a诱导的细胞凋亡,我们研究了外源表达CPNE5对TNF-a诱导的细胞凋亡的影响。与空载体转染组相比,外源表达CPNE5的HEK293细胞,在TNF-a作用后,细胞形态学上出现特征性的凋亡改变,如细胞外形模糊、细胞皱缩、细胞体积缩小等。流式细胞术检测结果显示,TNF-a处理12h或24h时,实验组细胞凋亡率高于对照组。分析介导凋亡的信号分子发现,凋亡核心成员半胱氨酸-天冬氨酸蛋白酶(caspase)的切割底物PARP参与了此过程。Western Blot结果表明,外源表达CPNE5促进了PARP的剪切。以上结果表明,CPNE5可以在一定程度上促进TNF-a诱导的细胞凋亡。而外源表达CPNE5对CHX和TNF-a(-/+)诱导的细胞凋亡无显著的影响。CHX是一种真核细胞蛋白翻译的常见抑制剂,它可以通过抑制核糖体亚基肽转移酶活性来阻止蛋白质的合成。以上实验结果表明CPNE5和CHX促进TNF-a诱导细胞凋亡的效应有重叠,这提示二者促凋亡机制可能有类似之处,即通过抑制抗凋亡蛋白的合成促进凋亡。
     我们在检测NF-κB下游基因时,发现一个有趣的现象:无TNF-a诱导时,过表达CPNE5能够显著增强NF-κB下游基因Bcl-xL的蛋白表达水平。此时,NF-κB的转录调控活性并没有被激活。Bcl-xL属于Bc1-2家族I类成员,具有抑制细胞凋亡的作用,已有报道表明Bcl-xL也参与了TNF-a对NF-κB活性的调控。进一步调研文献发现,Bcl-xL的表达除了受NF-κB调控外,还有很多因子可以调控它的表达,其中重要的如STATs和Ets等。由此,我们推测过表达CPNE5可能通过一条不依赖NF-κB活性的信号通路促Bcl-xL表达,而正由于Bcl-xL这种表达水平的升高,导致了尽管CPNE5有效地抑制了NF-κB的转录激活活性,却依然没有显著促进NF-κB诱导的细胞凋亡。为验证这一设想,我们钓取了人Bcl-xL基因并将其构建到真核表达载体。双荧光素酶报告基因实验结果显示,过表达Bcl-xL能够抑制NF-κB转录激活活性;转染Bcl-xL的RNA干涉片段SiRNA-BclxL,降低了Bcl-xL的表达同时弱化CPNE5对NF-κB活性的抑制,表明Bcl-xL可能在CPNE5抑制NF-κB转录激活活性过程中发挥重要的作用。
     本研究内容概括为:1.外源表达CPNE5抑制了TNF-a诱导了NF-κB的转录激活活性;CPNE5的A结构域也有这种抑制作用,并且呈现剂量依赖性;2. CPNE5不影响p65的出入核,表明CPNE5不通过NF-κB出入核调节机制来抑制NF-κB的活性,但CPEN5抑制了NF-κB与DNA结合的活性,且可以和P65相互作用;3. CPNE5促进了TNF-a诱导的凋亡率增加;但对CHX或TNF-a/CHX诱导的细胞凋亡无影响;4.成功钓取Bcl-xL基因;发现CPNE5表达诱导Bcl-xL表达水平上调;过表达Bcl-xL抑制NF-κB活性,SiRNA-BclxL弱化CPNE5对NF-κB活性的抑制,表明Bcl-xL可能参与CPNE5抑制NF-κB活性的过程。
     我们的研究首次证明了CPNE5及其保守结构域AD对NF-κB的转录激活具有抑制作用,其机制为CPNE5抑制NF-κB DNA结合活性,且可能和CPNE5与P65的结合有关。我们也研究了CPNE5对细胞凋亡的影响。过表达CPNE5抑制NF-κB的活性且促进凋亡。尽管过表达CPNE5也会上调Bcl-xL的表达,但在整个TNF-a诱导的细胞凋亡过程中,过表达CPNE5总体上呈现促凋亡的效应。
The copines are a novel family of ubiquitous Ca2+-dependent, phospholipid-binding proteins. Copines are comprised of two N-terminal C2 domains and a C-terminal A domain (AD). The C2 domains of copines are responsible for calcium and phospholipid-binding. C2 domains also present in proteins such as protein kinase C, phospholipase C and synaptotagmin. Because of A domain, copines may also be involved in protein-protein interactions since they contain a domain similar to the protein-binding‘A domain’of integrins. CPNE5 is mapped on chromosome 6p21.1. CPNE5 contains a complete open reading frame of 1782bp which encoding a 593 amino acid protein. Here, we show the studies on CPNE5 gene function, including its regulation in TNF-a induced NF-kB transcriptional activation and the possible mechanisms, and its role in apoptosis.
     In HEK293 cells, TNF-a treatment significantly increased CPNE5 mRNA expression. Dual-Luciferase Reporter Assay showed that exogenous expressed CPNE5 inhibited the transcriptional activity of NF-κB induced by TNF-a. RT-PCR results showed that overexpression of CPNE5 inhibited mRNA expression of NF-κB downstream genes such as Bcl-2. To investigate the role of C2 domains in the inhibition of NF-κB transcriptional activity, we constructed an AD-GFP expression vector with two C2 domain deletion. We found high expression of AD can significantly inhibit the transcriptional activity of NF-κB induced by TNF-a. The inhibition is dose-dependent with the amount of AD transfection. This indicates that AD domain plays an important role during the inhibition of NF-κB transcriptional activity.
     To further investigated the inhibitory mechanism, we established the tetracycline induced expression system (Tet-on) of CPNE5 in HEK293 cells. After Zeocin selection, we picked seven pcDNATM 4/TO-CPNE5 T-Rex-293 cell clone. CPNE5 was differentially expressed after 12h induction by tetracycline in these cells. We used the cell clones with the highest CPNE5 expression level to investigate the mechanism of CPNE5 inhibiting NF-κB activity. The translocation of NF-κB subunit P65 from cytoplasm to nucleus is the typical activation of NF-κB. We first detected whether CPNE5 overexpression inhibit the translocation of P65. Both western blot and imunofluorescence results showed that CPNE5 overexpression had no effect on translocation of P65 induced by TNF-a. These results indicate that CPNE5 did not suppress NF-κB transcriptional activity through the classical NF-κB regulatory pathway. However, electrophoretic mobility shift assay (EMSA) result showed that CPEN5 overexpression repressed NF-κB DNA-binding activity. Immunoprecipitation experiments showed that exogenous expressed CPNE5 interact with NF-κB (P65) directly.
     TNF-a induced activation of NF-κB plays important role in cell survival. To study whether exogenous expression of CPNE5 induces apoptosis through inhibiting the transcriptional activity of NF-κB, we explored the effect of exogenous CPNE5 on apoptosis induced by TNF-a. HEK293 cells were transfected with pcDNA3.1 and pcDNA3.1-CPNE5 respectively and treated with TNF-a, the apoptosis rate were detected by FACS analysis. Compared to the cells transfected with pcDNA3.1, cells transfected with pcDNA3.1-CPNE5 showed higher apoptsis rate. The cells expressing exogenous CPNE5 showed characteristic morphological changes of apoptosis, such as cell shape fuzzy, cell shrinkage, reduced cell volume and so on. Further investigation into the apoptosis signaling showed that PARP, a cutting substrate of caspase, is involved in the above process. Western blot result showed that exogenous expression of CPNE5 promoted PARP cleavage. These results showed that CPNE5 could promote TNF-a induced apoptosis to some degree. Exogenous expression of CPNE5 had no significant effect on CHX (TNF-a–/+) induced apoptosis. CHX is a most common inhibitor of eukaryotic protein translation, which can inhibit the 60S ribosomal subunit peptide transferase activity to prevent protein synthesis. These results showed that exogenous expression of CPNE5 regulated TNF-a induced apoptosis process involved with synthesis of protective protein.
     Further investigation of the expression of NF-κB downstream genes, we found an interesting result. Without TNF-a induced activation of NF-κB, overexpressed CPNE5 upregulate Bcl-xL expression significantly. Bcl-xL, a member of the Bcl-2 family, is also known to inhibit TNF-a-induced apoptosis. We cloned the cDNA and constructed the eukaryotic expression vector of Bcl-xL. Overexpression of Bcl-xL inhibited the transcriptional activity of NF-κB. Downregulate the expression of Bcl-xL with SiRNA-Bcl-xL weaken the inhibition of NF-κB activity by CPNE5. These results indicate that Bcl-xL may play an important role in inhibition of NF-κB transcriptional activation by CPNE5.
     This research summarized as: 1. exogenous expression of CPNE5 inhibited the TNF-a induced NF-κB transcriptional activity; A domain of CPNE5 also had this inhibitory effect in dose-dependent manner; 2. CPNE5 had no effect on translocation of P65; CPNE5 did not suppress NF-κB transcriptional activity through the classical NF-κB regulatory pathway, but CPEN5 inhibited DNA binding activity of NF-κB and interacted with P65; 3. CPNE5 promoted TNF-a induced apoptosis but had no effect on apoptosis induced byCHX or TNF-a/CHX; 4. overexpressed CPNE5 upregulate Bcl-xL expression; overexpression of Bcl-xL inhibited NF-κB activity; SiRNA-BclxL weaken the inhibition of NF-κB activity by CPNE5, these indicated that Bcl-xL may be involved in inhibition of NF-κB activity by CPNE5.
     Our results for the first time revealed that CPNE5 inhibit NF-κB transcriptional activity. CPNE5 might block the DNA binding activity of NF-κB through interacting with p65. In addition, we also found that overexpression of CPNE5 enhance cell apoptosis induced by TNF-a. The upregulation of Bcl-xL expression by CPNE5 might play a certain role in this process.
引文
[1] J. F. R. Kerr, A. H. Wyllie, A. R. Currie. Apoptosis: A Basic Biological Phenomenon with Wide-ranging Implications in Tissue Kinetics[J]. Br J Cancer. 1972, 26(4): 239–257.
    [2] Fan TJ, Han LH, Cong RS, Liang J. Caspase family proteases and apoptosis[J]. Acta Biochim Biophys Sin (Shanghai). 2005, 37(11):719-727.
    [3]Brunelle JK, Letai A. Control of mitochondrial apoptosis by the Bcl-2 family[J]. J Cell Sci. 2009, 122(Pt 4):437-41.
    [4]Gustafsson AB, Gottlieb RA. Bcl-2 family members and apoptosis, taken to heart[J]. Am J Physiol Cell Physiol. 2007, 292(1):45-51.
    [5]Meulmeester E, Jochemsen AG. p53: a guide to apoptosis[J]. Curr Cancer Drug Targets. 2008, 8(2):87-97.
    [6]Kucharczak J, Simmons MJ, Fan Y, et al. To be, or not to be: NF-kappaB is the answer-role of Rel/NF-kappaB in the regulation of apoptosis[J]. Oncogene. 2003, 22(56):8961-8982.
    [7] Heyninck K, Beyaert R. Crosstalk between NF-kappaB-activating and apoptosis-inducing proteins of the TNF-receptor complex[J]. Mol Cell Biol Res Commun. 2001, 4(5):259-265.
    [8] Barkett M, Gilmore TD. Control of apoptosis by Rel/NF-kappaB transcription factors[J]. Oncogene. 1999, 18(49):6910-6924.
    [9] Creutz CE, Tomsig JL, Snyder SL, et al. The copines, a novel class of C2 domain-containing, calcium-dependent, phospholipid-binding proteins conserved from Paramecium to humans[J]. J Biol Chem. 1998, 273(3):1393-1402.
    [10] Pesho MM, Bledzka K, Michalec L, et al. The specificity and function of the metal-binding sites in the integrin beta3 A-domain[J]. J Biol Chem. 2006, 281(32):23034-23041.
    [11] Eble JA, Tuckwell DS. The alpha2beta1 integrin inhibitor rhodocetin binds to the A-domain of the integrin alpha2 subunit proximal to the collagen-binding site[J]. Biochem J. 2003, 376(Pt 1):77-85.
    [12] Ramsey CS, Yeung F, Stoddard PB, et al. Copine-I represses NF-κB transcription by endoproteolysis of p65[J]. Oncogene, 2008, 27(25):3516-3526.
    [13] Heinrich C, Keller C, Boulay A, et al. Copine-III interacts with ErbB2 and promotes tumor cell migration[J]. Oncogene. 2010, 29(11):1598-610.
    [14] Sen R, Baltimore D. Multiple nuclear factors interact with the immunoglobulin enhancer sequences[J]. Cell, 1986, 46(5): 705-716.
    [15] Beg AA, Sha WC, Bronson RT, et al. Embryonic lethality and liver degeneration in mice lacking the RelA component of NF-kappaB[J]. Nature. 1995, 376(6536):167-170.
    [16] Wang CY, Cusack JC Jr, Liu R, et al. Control of inducible chemoresistance: enhanced anti-tumor therapy through increased apoptosis by inhibition of NF-κB[J]. Nat Med. 1999, 5(4):412-417.
    [17] Hayden MS, Ghosh S. Signaling to NF-kappaB[J]. Genes Dev. 2004 Sep 15;18(18):2195-2224.
    [18] Senftleben U, Cao Y, Xiao G, et al. Activation by IKKalpha of a second, evolutionary conserved, NF-kappa B signaling pathway[J]. Science. 2001, 293(5534): 1495-1499.
    [19] Wu Y, Zhou BP. TNF-alpha/NF-kappaB/Snail pathway in cancer cell migration and invasion[J]. Br J Cancer. 2010, 102(4):639-644.
    [20] Victor FC, Gottlieb AB. TNF-alpha and apoptosis: implications for the pathogenesis and treatment of psoriasis[J]. J Drugs Dermatol. 2002, 1(3):264-275.
    [21] Carswell EA, Old LJ, Kassel RL, et al. An endotoxin-induced serum factor that causes necrosis of tumors[J]. Proc Natl Acad Sci U S A. 1975, 72(9):3666-3670.
    [22] Wajant H, Henkler F, Scheurich P. The TNF-receptor-associated factor family: scaffold molecules for cytokine receptors, kinases and their regulators[J]. Cell Signal. 2001, 13(6):389-400.
    [23] Bharti AC, Aggarwal BB. Nuclear factor-kappa B and cancer: its role in prevention and therapy[J]. Biochem Pharmacol. 2002, 64(5-6):883-888.
    [24] Dutta J, Fan Y, Gupta N, et al. Current insights into the regulation of programmed cell death by NF-kappaB[J]. Oncogene. 2006, 25(51):6800-6816.
    [25] Hsu H, Shu HB, Pan MG, et al. TRADD-TRAF2 and TRADD-FADD interactions define two distinct TNF receptor 1 signal transduction pathways[J]. Cell. 1996, 84(2):299-308.
    [26] Rothe M, Sarma V, Dixit VM, et al. TRAF2-mediated activation of NF-kappa B by TNF receptor 2 and CD40[J]. Science. 1995, 269(5229):1424-1427.
    [27] Wang CY, Mayo MW, et al. TNF-a and cancer therapy-induced apoptosis: potentiation by inhibition of NF-κB[J]. Science , 1996, 274(5288): 784-787.
    [28] Heyninck K, Beyaert R. Crosstalk between NF-kappaB-activating andapoptosis-inducing proteins of the TNF-receptor complex[J]. Mol Cell Biol Res Commun. 2001, 4(5):259-265.
    [29] Tsujimoto, Y. and Shimizu, S. Bcl-2 family: life-or-death switch[J]. FEBS Lett. 2000, 466(1):6-10.
    [30] Marsden VS, O'Connor L, O'Reilly LA, et al. Apoptosis initiated by Bcl-2-regulated caspase activation independently of the cytochrome c/Apaf-1/caspase-9 apoptosome[J]. Nature. 2002, 419(6907):634-637.
    [31] Kim YG, Kim JY, Mohan C, et al. Effect of Bcl-xL overexpression on apoptosis and autophagy in recombinant Chinese hamster ovary cells under nutrient-deprived condition. Biotechnol Bioeng[J]. 2009, 103(4):757-766.
    [32] Fujimura S, Suzumiya J, Yamada Y, et al. Downregulation of Bcl-xL and activation of caspases during retinoic acid-induced apoptosis in an adult T-cell leukemia cell line[J]. Hematol J. 2003, 4(5):328-335.
    [33]王晓文,靳雁斌,吴燕,等. CopineⅤ蛋白的亚细胞定位[J].生物技术通讯, 2006, 17(2):149-151.
    [34] Ferreiro DU, Komives EA. Molecular mechanisms of system control of NF-kappaB signaling by IkappaBalpha. Biochemistry[J]. 2010, 49(8):1560-1567.
    [35] Goto K, Chiba Y, Sakai H, et al. Tumor necrosis factor-alpha (TNF-alpha) induces upregulation of RhoA via NF-kappaB activation in cultured human bronchial smooth muscle cells[J]. J Pharmacol Sci. 2009, 110(4):437-444.
    [36] Dhingra S, Sharma AK, Arora RC, et al. IL-10 attenuates TNF-alpha-induced NF kappaB pathway activation and cardiomyocyte apoptosis[J]. Cardiovasc Res. 2009, 82(1):59-66.
    [37] Sarkar D, Park ES, Emdad L, et al. Molecular basis of nuclear factor-kappaB activation by astrocyte elevated gene-1[J]. Cancer Res. 2008, 68(5):1478-1484.
    [38] Nozell S, Laver T, Moseley D, et al. The ING4 tumor suppressor attenuates NF-kappaB activity at the promoters of target genes[J]. Mol Cell Biol. 2008, 28(21): 6632-6645.
    [39] Chen Y, Li HH, Fu J, et al. Oncoprotein p28 GANK binds to RelA and retains NF-kappaB in the cytoplasm through nuclear export[J]. Cell Res. 2007, 17(12): 1020-1029.
    [40] Ghosh S , May MJ , Kopp EB. NF-kappaB and Rel proteins:evolutionarily conserved mediators of immune responses[J]. Annu Rev Immunol. 1998, 16:225-260..
    [41] Maniatis T. A ubiquitin ligase complex essential for the NF-kappaB,Wnt/Wingless, and Hedgehog signaling pathways[J]. Genes Dev. 1999, 13(5):505-510.
    [42] Baldi L , Brown K , Franzoso G , et al . Critical role for lysines 21and 22 in signal-induced, ubiquitin-mediated proteolysis of IkappaB-alpha[J]. J Biol Chem. 1996, 271(1):376-379.
    [43] Hershko A, Ciechanover A. The ubiquitin system[J]. Annu Rev Biochem. 1998, 67:425-479.
    [44] Béraud C, Henzel WJ, Baeuerle PA. Involvement of regulatory and catalytic subunits of phosphoinositide 3-kinase in NF-kappaB activation[J]. Proc Natl Acad Sci USA. 1999, 96(2):429-434.
    [45] Li N , Karin M. Ionizing radiation and short wave length UV activate NF-κB through two distinct mechanisms[J]. Proc Natl Acad Sci USA. 1998, 95(22): 13012-13017.
    [46] Schmeisser F, Donohue M, Weir JP. Tetracycline-regulated gene expression in replication-incompetent herpes simplex virus vectors[J]. Hum Gene Ther. 2002, 13(18):2113-2124.
    [47] Zhong H, Voll RE, Ghosh S. Phosphorylation of NF-kappa B p65 by PKA stimulates transcriptional activity by promoting a novel bivalent interaction with the coactivator CBP/p300[J]. Mol Cell, 1998, 1(5):661-671.
    [48] Kiernan R, Brès V, Ng RW, et al. Post-activation turn-off of NF-κB dependent transcription is regulated by acetylation of p65[J]. J Biol Chem, 2003, 278(4): 2758-2766.
    [49] Kang KH, Lee KH, Kim MY, et al. Caspase-3-mediated cleavage of the NF-κB subunit p65 at the NH2 terminus potentiates naphthoquinone analog-induced apoptosis[J]. J Biol Chem, 2001, 276(27):24638-24644.
    [50] Bonnard M, Mirtsos C, Suzuki S, et al. Deficiency of T2K leads to apoptotic liver degeneration and impaired NF-κB-dependent gene transcription[J]. EMBO J, 2000, 19(18):4976-4985.
    [51] Schwabe RF, Brenner DA. Role of glycogen synthase kinase-3 in TNF-alpha-induced NF-kappaB activation and apoptosis in hepatocytes[J]. Am J Physiol Gastrointest Liver Physiol. 2002, 283(1): G204-G211.
    [52] Wan F, Lenardo MJ. The nuclear signaling of NF-kappaB: current knowledge, new insights, and future perspectives[J]. Cell Res. 2010, 20(1):24-33.
    [53] Dutta J, Fan Y, Gupta N, et al. Current insights into the regulation ofprogrammed cell death by NF-kappaB[J]. Oncogene. 2006, 25(51):6800-6816.
    [54] Ferrington D A,Tran T N,Kathleen L.Diferent death stimuli eyoke apoptosis iva multiple pathways in retinal pigment epithelial cell[J].Exp Eye Res, 2006, 83:638-650.
    [55] Ashkenazi A. Targeting death and decoy receptors of the tumoumecrosis factor superfamily[J]. Nat Rev Cancer. 2002, 2(6):420-430.
    [56] Ran R, Lu A, Zhang L, et al. Hsp70 promotes TNF-mediated apoptosis by binding IKK gamma and impairing NF-kappaB survival signaling[J]. Genes Dev. 2004, 18(12):1466-1481.
    [57] Lee TJ, Jang JH, Noh HJ, et al. Overexpression of Par-4 sensitizes TRAIL-induced apoptosis via inactivation of NF-kappaB and Akt signaling pathways in renal cancer cells[J]. J Cell Biochem. 2010, 109(5):885-895.
    [58] Konishi T, Sasaki S, Watanabe T, et al. Overexpression of hRFI inhibits 5-fluorouracil-induced apoptosis in colorectal cancer cells via activation of NF-kappaB and upregulation of BCL-2 and BCL-XL[J]. Oncogene. 2006, 25(22): 3160-3169.
    [59]董波,饶亚岚,鲁茁壮等.一种新的GFP/DNA双标记流式细胞技术[J].军事医学科学院院刊. 2004, 28(6):565-568.
    [60] Boulares AH, Yakovlev AG, Ivanova V, et al. Role of poly(ADP-ribose) polymerase (PARP) cleavage in apoptosis. Caspase 3-resistant PARP mutant increases rates of apoptosis in transfected cells[J]. J Biol Chem. 1999, 274(33):22932-22940.
    [61] Petros AM, Olejniczak ET, Fesik SW. Structural biology of the Bcl-2 family of proteins[J]. Biochim Biophys Acta. 2004, 1644(2-3):83-94.
    [62] Kirkin V, Joos S, Z?rnig M. The role of Bcl-2 family members in tumorigenesis[J]. Biochim Biophys Acta. 2004, 1644(2-3):229-249.
    [63] Grimm S, Bauer MK, Baeuerle PA, et al. Bcl-2 down-regulates the activity of transcription factor NF-kappaB induced upon apoptosis[J]. J Cell Biol. 1996, 134(1): 13-23.
    [64] Battle TE, Frank DA. The role of STATs in apoptosis[J]. Curr Mol Med. 2002, 2(4):381-392.
    [65] Sanij E, Hatzistavrou T, Hertzog P, et al. Ets-2 is induced by oxidative stress and sensitizes cells to H2O2-induced apoptosis: implications for Down's syndrome[J]. Biochem Biophys Res Commun. 2001, 287(4):1003-1008.
    [66] Zhang Q, Badell IR, Schwarz EM, et al. Tumor necrosis factor preventsalendronate-induced osteoclast apoptosis in vivo by stimulating Bcl-xL expression through Ets-2[J]. Arthritis Rheum. 2005, 52(9):2708-2718.
    [67] Sun A, Tang J, Hong Y, et al. Androgen receptor-dependent regulation of Bcl-xL expression: Implication in prostate cancer progression[J]. Prostate. 2008, 68(4):453-461.
    [68] Khoshnan A, Tindell C, Laux I, et al. The NF-kappa B cascade is important in Bcl-xL expression and for the anti-apoptotic effects of the CD28 receptor in primary human CD4+ lymphocytes[J]. J Immunol. 2000, 165(4):1743-1754.
    [69] Alfano D, Iaccarino I, Stoppelli MP. Urokinase signaling through its receptor protects against anoikis by increasing Bcl-xL expression levels[J]. J Biol Chem. 2006, 281(26):17758-67.
    [70] Gascoyne DM, Kypta RM, Vivanco MM. Glucocorticoids inhibit apoptosis during fibrosarcoma development by transcriptionally activating Bcl-xL[J]. J Biol Chem. 2003, 278(20):18022-18029.
    [71] Grad JM, Zeng XR, Boise LH. Regulation of Bcl-xL: a little bit of this and a little bit of STAT[J]. Curr Opin Oncol. 2000, 12(6):543-549.
    [72] Ji L, Chen Y, Liu T, et al. Involvement of Bcl-xL degradation and mitochondrial-mediated apoptotic pathway in pyrrolizidine alkaloids-induced apoptosis in hepatocytes. Toxicol Appl Pharmacol. 2008, 231(3):393-400.
    [73] Liu Z, Wang S, Zhou H,et al. Na+/H+ exchanger mediates TNF-alpha-induced hepatocyte apoptosis via the calpain-dependent degradation of Bcl-xL. J Gastroenterol Hepatol. 2009, 24(5):879-885.
    [74] Luo W, Lin S C. Axin: a master scaffold for multiple signaling pathways[J]. Neurosignals, 2004, 13 (3):99-113.
    [75] Kikuchi A. Roles of Axin in the Wnt signalling pathway[J]. Cell Signal. 1999, 11(11):777-788.
    [76] Shiomi K, Uchida H, Keino Masu K, et al. Ccd1, a novel protein with a DIX domain, is a positive regulator in the Wnt signaling during zebrafish neural patterning[J]. Curr Biol, 2003, 13(1):73-77.
    [77] Shiomi K, Kanemoto M, Keino-Masu K, et al. Identification and differential expression of multiple isoforms of mouse Coiled-coil-DIX1(Ccd1), a positive regulator of Wnt signaling[J]. Brain Res Mol Brain Res. 2005, 135(1-2):169-180.
    [78] Wiese C, Zheng Y. Microtubule nucleation: gamma-tubulin and beyond[J]. J Cell Sci. 2006, 119(Pt20):4143-4153.
    [79] Oakley BR. gamma-Tubulin[J]. Curr Top Dev Biol. 2000, 49:27-54.
    [80] Gunawardane RN, Lizarraga SB, Wiese C, et al. gamma-Tubulin complexes and their role in microtubule nucleation[J]. Curr Top Dev Biol. 2000, 49:55-73.
    [81] Kong Z, Hotta T, Lee YR, et al. The {gamma}-tubulin complex protein GCP4 is required for organizing functional microtubule arrays in Arabidopsis thaliana[J]. Plant Cell. 2010, 22(1):191-204.
    [82] Jing XT, Wu HT, Wu Y, et al. DIXDC1 promotes retinoic acid-induced neuronal differentiation and inhibits gliogenesis in P19 cells[J]. Cell Mol Neurobiol. 2009, 29(1):55-67.
    [83] Wang L, Cao XX, Chen Q, et al. DIXDC1 targets p21 and cyclin D1 via PI3K pathway activation to promote colon cancer cell proliferation[J]. Cancer Sci. 2009, 100(10):1801-1808.
    [1] Sen R, Baltimore D. Multiple nuclear factors interact with the immunoglobulin enhancer sequences[J]. Cell, 1986, 46(5): 705-716.
    [2] Devin A, Cook A, Lin Y, et al. The distinct roles of TRAF2 and RIP in IKKactivation by TNF-R1: TRAF2 recruits IKK to TNF-R1 while RIP mediates IKKactivation[J]. Immunity, 2000, 12(4):419~29.
    [3] Senftleben U, Cao Y, Xiao G, et al. Activation by IKKalpha of a second,evolutionary conserved, NF-kappa B signaling pathway[J]. Science, 2001, 293(5534): 1495-1499.
    [4] Dejardin E, Droin NM, Delhase M, et al. The lymphotoxin-beta receptor inducesdifferent patterns of gene expression via two NF-kappaB pathways[J]. Immunity,2002, 17(4):525-535.
    [5] Bonnard M, Mirtsos C, Suzuki S, et al. Deficiency of T2K leads to apoptotic liverdegeneration and impaired NF-KB-dependent gene transcription[J]. EMBO J, 2000,19(18): 4976-4985.
    [6] Schwabe RF, Brenner DA. Role of glycogen synthase kinase-3 inTNF-alpha-induced NF-kappaB activation and apoptosis in hepatocytes[J]. Am JPhysiol Gastrointest Liver Physiol, 2002, 283(1): G204-G211.
    [7] Zhong H, Voll RE, Ghosh S. Phosphorylation of NF-kappa B p65 by PKAstimulates transcriptional activity by promoting a novel bivalent interaction with thecoactivator CBP/p300[J]. Mol Cell, 1998, 1(5):661-671.
    [8] Vermeulen L, De Wilde G, Van Damme P, et al. Transcriptional activation of theNF-kappaB p65 subunit by mitogenand stress-activated protein kinase-l (MSK1)[J].EMBO J, 2003, 22(6): 1313-1324.
    [9] Duran A, Diaz-Meco MT, Moscat J. Essential role of RelA Ser3llphosphorylation by zetaPKC in NF-kappaB transcriptional activation[J]. EMBO J,2003, 22(15):3910-3918.
    [10] Sakurai H, Chiba H, Miyoshi H, et al. IkB kinases phosphorylate NF-kB p65 subunit on serine 536 in the transactivation domain[J]. J Biol Chem, 1999, 274(43):30353-30356.
    [11] O'Mahony AM, Montano M, Van Beneden K, et al. Human T-cell lymphotropic virus type 1 tax induction of biologically Active NF-kB requires IkB kinase-1-mediated phosphorylation of RelA/p65[J]. J Biol Chem, 2004 279(18): 18137-18145.
    [12] Chen Lf, Fischle W, Verdin E, et al. Duration of nuclear NF-kB action regulatedby reversible acetylation[J]. Science, 2001, 293(5535): 1653-1657.
    [13] Kiernan R, Bres V, Ng RW, et al. Post-activation turn-off of NF-kB dependenttranscription is regulated by acetylation of p65[J]. J Biol Chem, 2003,278(4):2758-2766.
    [14] Chen LF, Mu Y, Greene WC. Acetylation of RelA at discrete sites regulatesdistinct nuclear functions of NF-kappaB [J]. EMBO J, 2002, 21(23): 6539-6548.
    [15] Kang KH, Lee KH, Kim MY, et al. Caspase-3-mediated cleavage of the NF-kBsubunit p65 at the NH2 terminus potentiates naphthoquinone analog-inducedapoptosis[J]. JBiol Chem, 2001, 276(27):24638-24644.
    [16] Ramsey CS, Yeung F, Stoddard PB, et al. Copine-I represses NF-kB transcriptionby endoproteolysis of p65[J]. Oncogene, 2008, 27(25):3516-3526.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700