Glucose-regulated protein 78 (GRP78), a key regulator of endoplasmic reticulum stress, facilitates cancer cell growth and viral replication. The mechanism leading to GRP78 gene activation during viral infection is largely unknown. Here, we show that the immediate-early 1 (IE1-72) protein of the human cytomegalovirus (HCMV) is essential for HCMV-mediated GRP78 activation. IE1-72 up-regulated grp78 gene expression depending on the ATP binding site, the zinc finger domain and the putative leucine zipper motif of IE1-72, as well as the ER stress response elements (ERSEs) on the grp78 promoter. The purified IE1-72 protein bound to the CCAAT box within ERSE in vitro, whereas deletion mutants of IE1 deficient in grp78 promoter stimulation failed to do so. Moreover, IE1-72 binding to the grp78 promoter in infected cells accompanied the recruitment of TBP-associated factor 1 (TAF1), a histone acetyltransferase, and the increased level of acetylated histone 4, an indicator of active-state chromatin. These results provide evidence that HCMV IE1-72 activates grp78 gene expression through direct promoter binding and modulation of the local chromatin structure, indicating an active viral mechanism of cellular chaperone induction for viral growth.

葡萄糖調控蛋白78 (GRP78) 在內質網逆境刺激反應調控扮演重要角色，並參與癌細胞的生長與病毒複製過程。然而，病毒調控GRP78的基因表達之機制未明。本論文研究提供一系列實驗證明，指出人類巨細胞病毒 (human cytomegalovirus) 之迅早期蛋白1-72 (IE1-72) 於病毒複製過程中調控GRP78基因之大量表達。IE1-72借由其三個功能區域—三磷酸腺苷結合區、鋅指區域與預測為亮氨酸拉鍊序列—調控GRP78的基因表現。此外，位在GRP78啟動子上的內質網逆境反應序列 (ERSE) 對IE1-72的調控來說，也不可或缺。為進一步討論其機制，我們於大腸桿菌中表達並純化IE1-72，發現純化之IE1-72於試管中可與ERSE序列中的CCAAT區域結合。此發現指出IE1-72可能為去氧核醣核酸(DNA)結合蛋白。相關實驗更指出去除上述所提及的三個功能區域之變種IE1-72均使其喪失與ERSE結合的能力。此外，細胞內染色質免疫沈澱技術證明IE1-72確實與GRP78的啟動子結合，並伴隨著組蛋白乙醯基轉移酶TATA聯結相關蛋白1 (TAF1) 與GRP78啟動子之結合，及GRP78啟動子組蛋白4之甲基化增加—這些都使得啟動子的活性上升，而導致轉錄效率上升。另外，利用短髮夾RNA (small hairpin RNA) 技術抑制GRP78之表達，病毒DNA複製量亦隨之下降。這些結果首次顯示IE1-72可經由與DNA結合之機制直接調控GRP78啟動子而表達大量GRP78，最終促進病毒複製。

1. Fink AL. Chaperone-mediated protein folding. Physiol Rev 1999; 79:425-449.
2. Lee AS. The glucose-regulated proteins: stress induction and clinical applications. Trends Biochem Sci 2001; 26:504-510.
3. Okada T, Yoshida H, Akazawa R, Negishi M, Mori K. Distinct roles of activating transcription factor 6 (ATF6) and double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase (PERK) in transcription during the mammalian unfolded protein response. Biochem J 2002; 366:585-594.
4. Shen J, Chen X, Hendershot L, Prywes R. ER stress regulation of ATF6 localization by dissociation of BiP/GRP78 binding and unmasking of Golgi localization signals. Dev Cell 2002; 3:99-111.
5. Harding HP, Zhang Y, Ron D. Protein translation and folding are coupled by an endoplasmic-reticulum-resident kinase. Nature 1999; 397:271-274.
6. Bertolotti A, Zhang Y, Hendershot LM, Harding HP, Ron D. Dynamic interaction of BiP and ER stress transducers in the unfolded-protein response. Nat Cell Biol 2000; 2:326-332.
7. Yoshida H, Matsui T, Yamamoto A, Okada T, Mori K. XBP1 mRNA is induced by ATF6 and spliced by IRE1 in response to ER stress to produce a highly active transcription factor. Cell 2001; 107:881-891.
8. Sriburi R, Jackowski S, Mori K, Brewer JW. XBP1: a link between the unfolded protein response, lipid biosynthesis, and biogenesis of the endoplasmic reticulum. J Cell Biol 2004; 167:35-41.
9. Yoshida H, Oku M, Suzuki M, Mori K. pXBP1(U) encoded in XBP1 pre-mRNA negatively regulates unfolded protein response activator pXBP1(S) in mammalian ER stress response. J Cell Biol 2006; 172:565-575.
10. Urano F, Wang X, Bertolotti A et al. Coupling of stress in the ER to activation of JNK protein kinases by transmembrane protein kinase IRE1. Science 2000; 287:664-666.
11. Yoneda T, Imaizumi K, Oono K et al. Activation of caspase-12, an endoplastic reticulum (ER) resident caspase, through tumor necrosis factor receptor-associated factor 2-dependent mechanism in response to the ER stress. J Biol Chem 2001; 276:13935-13940.
12. Hollien J, Weissman JS. Decay of endoplasmic reticulum-localized mRNAs during the unfolded protein response. Science 2006; 313:104-107.
13. Nadanaka S, Yoshida H, Kano F, Murata M, Mori K. Activation of mammalian unfolded protein response is compatible with the quality control system operating in the endoplasmic reticulum. Mol Biol Cell 2004; 15:2537-2548.
14. Ye J, Rawson RB, Komuro R et al. ER stress induces cleavage of membrane-bound ATF6 by the same proteases that process SREBPs. Mol Cell 2000; 6:1355-1364.
15. Mori K. Signaling pathways in the unfolded protein response: development from yeast to mammals. J Biochem 2009.
16. Zhang K, Shen X, Wu J et al. Endoplasmic reticulum stress activates cleavage of CREBH to induce a systemic inflammatory response. Cell 2006; 124:587-599.
17. Liang G, Audas TE, Li Y et al. Luman/CREB3 induces transcription of the endoplasmic reticulum (ER) stress response protein Herp through an ER stress response element. Mol Cell Biol 2006; 26:7999-8010.
18. Kim HC, Choi KC, Choi HK et al. HDAC3 selectively represses CREB3-mediated transcription and migration of metastatic breast cancer cells. Cell Mol Life Sci 2010; 67:3499-3510.
19. Kondo S, Murakami T, Tatsumi K et al. OASIS, a CREB/ATF-family member, modulates UPR signalling in astrocytes. Nat Cell Biol 2005; 7:186-194.
20. Kondo S, Saito A, Hino S et al. BBF2H7, a novel transmembrane bZIP transcription factor, is a new type of endoplasmic reticulum stress transducer. Mol Cell Biol 2007; 27:1716-1729.
21. Saito A, Hino S, Murakami T et al. Regulation of endoplasmic reticulum stress response by a BBF2H7-mediated Sec23a pathway is essential for chondrogenesis. Nat Cell Biol 2009; 11:1197-1204.
22. Nagamori I, Yabuta N, Fujii T et al. Tisp40, a spermatid specific bZip transcription factor, functions by binding to the unfolded protein response element via the Rip pathway. Genes Cells 2005; 10:575-594.
23. Stirling J, O'Hare P. CREB4, a transmembrane bZip transcription factor and potential new substrate for regulation and cleavage by S1P. Mol Biol Cell 2006; 17:413-426.
24. Yoshida H, Haze K, Yanagi H, Yura T, Mori K. Identification of the cis-acting endoplasmic reticulum stress response element responsible for transcriptional induction of mammalian glucose-regulated proteins. Involvement of basic leucine zipper transcription factors. J Biol Chem 1998; 273:33741-33749.
25. Thuerauf DJ, Marcinko M, Belmont PJ, Glembotski CC. Effects of the isoform-specific characteristics of ATF6 alpha and ATF6 beta on endoplasmic reticulum stress response gene expression and cell viability. J Biol Chem 2007; 282:22865-22878.
26. Audas TE, Li Y, Liang G, Lu R. A novel protein, Luman/CREB3 recruitment factor, inhibits Luman activation of the unfolded protein response. Mol Cell Biol 2008; 28:3952-3966.
27. Yoshida H, Uemura A, Mori K. pXBP1(U), a negative regulator of the unfolded protein response activator pXBP1(S), targets ATF6 but not ATF4 in proteasome-mediated degradation. Cell Struct Funct 2009; 34:1-10.
28. Vattem KM, Wek RC. Reinitiation involving upstream ORFs regulates ATF4 mRNA translation in mammalian cells. Proc Natl Acad Sci U S A 2004; 101:11269-11274.
29. Lu PD, Harding HP, Ron D. Translation reinitiation at alternative open reading frames regulates gene expression in an integrated stress response. J Cell Biol 2004; 167:27-33.
30. Harding HP, Novoa I, Zhang Y et al. Regulated translation initiation controls stress-induced gene expression in mammalian cells. Mol Cell 2000; 6:1099-1108.
31. Novoa I, Zeng H, Harding HP, Ron D. Feedback inhibition of the unfolded protein response by GADD34-mediated dephosphorylation of eIF2alpha. J Cell Biol 2001; 153:1011-1022.
32. Lee AH, Iwakoshi NN, Glimcher LH. XBP-1 regulates a subset of endoplasmic reticulum resident chaperone genes in the unfolded protein response. Mol Cell Biol 2003; 23:7448-7459.
33. van Huizen R, Martindale JL, Gorospe M, Holbrook NJ. P58IPK, a novel endoplasmic reticulum stress-inducible protein and potential negative regulator of eIF2alpha signaling. J Biol Chem 2003; 278:15558-15564.
34. Yan W, Frank CL, Korth MJ et al. Control of PERK eIF2alpha kinase activity by the endoplasmic reticulum stress-induced molecular chaperone P58IPK. Proc Natl Acad Sci U S A 2002; 99:15920-15925.
35. Marciniak SJ, Yun CY, Oyadomari S et al. CHOP induces death by promoting protein synthesis and oxidation in the stressed endoplasmic reticulum. Genes Dev 2004; 18:3066-3077.
36. Calfon M, Zeng H, Urano F et al. IRE1 couples endoplasmic reticulum load to secretory capacity by processing the XBP-1 mRNA. Nature 2002; 415:92-96.
37. Dudek J, Greiner M, Muller A et al. ERj1p has a basic role in protein biogenesis at the endoplasmic reticulum. Nat Struct Mol Biol 2005; 12:1008-1014.
38. Maattanen P, Gehring K, Bergeron JJ, Thomas DY. Protein quality control in the ER: the recognition of misfolded proteins. Semin Cell Dev Biol 2010; 21:500-511.
39. Sun FC, Wei S, Li CW et al. Localization of GRP78 to mitochondria under the unfolded protein response. Biochem J 2006; 396:31-39.
40. Xiao G, Chung TF, Pyun HY, Fine RE, Johnson RJ. KDEL proteins are found on the surface of NG108-15 cells. Brain Res Mol Brain Res 1999; 72:121-128.
41. Ni M, Zhou H, Wey S, Baumeister P, Lee AS. Regulation of PERK signaling and leukemic cell survival by a novel cytosolic isoform of the UPR regulator GRP78/BiP. PLoS One 2009; 4:e6868.
42. Quinones QJ, de Ridder GG, Pizzo SV. GRP78: a chaperone with diverse roles beyond the endoplasmic reticulum. Histol Histopathol 2008; 23:1409-1416.
43. Reddy RK, Mao C, Baumeister P et al. Endoplasmic reticulum chaperone protein GRP78 protects cells from apoptosis induced by topoisomerase inhibitors: role of ATP binding site in suppression of caspase-7 activation. J Biol Chem 2003; 278:20915-20924.
44. Fu Y, Li J, Lee AS. GRP78/BiP inhibits endoplasmic reticulum BIK and protects human breast cancer cells against estrogen starvation-induced apoptosis. Cancer Res 2007; 67:3734-3740.
45. Misra UK, Gonzalez-Gronow M, Gawdi G et al. The role of Grp 78 in alpha 2-macroglobulin-induced signal transduction. Evidence from RNA interference that the low density lipoprotein receptor-related protein is associated with, but not necessary for, GRP 78-mediated signal transduction. J Biol Chem 2002; 277:42082-42087.
46. Misra UK, Deedwania R, Pizzo SV. Binding of activated alpha2-macroglobulin to its cell surface receptor GRP78 in 1-LN prostate cancer cells regulates PAK-2-dependent activation of LIMK. J Biol Chem 2005; 280:26278-26286.
47. Misra UK, Payne S, Pizzo SV. Ligation of prostate cancer cell surface GRP78 activates a pro-proliferative and anti-apoptotic feedback loop: A role for secreted PSA. J Biol Chem 2010.
48. Kelber JA, Panopoulos AD, Shani G et al. Blockade of Cripto binding to cell surface GRP78 inhibits oncogenic Cripto signaling via MAPK/PI3K and Smad2/3 pathways. Oncogene 2009; 28:2324-2336.
49. Shani G, Fischer WH, Justice NJ et al. GRP78 and Cripto form a complex at the cell surface and collaborate to inhibit transforming growth factor beta signaling and enhance cell growth. Mol Cell Biol 2008; 28:666-677.
50. Philippova M, Ivanov D, Joshi MB et al. Identification of proteins associating with glycosylphosphatidylinositol- anchored T-cadherin on the surface of vascular endothelial cells: role for Grp78/BiP in T-cadherin-dependent cell survival. Mol Cell Biol 2008; 28:4004-4017.
51. McFarland BC, Stewart J, Jr., Hamza A et al. Plasminogen kringle 5 induces apoptosis of brain microvessel endothelial cells: sensitization by radiation and requirement for GRP78 and LRP1. Cancer Res 2009; 69:5537-5545.
52. Al-Hashimi AA, Caldwell J, Gonzalez-Gronow M et al. Binding of anti-GRP78 autoantibodies to cell surface GRP78 increases tissue factor procoagulant activity via the release of calcium from endoplasmic reticulum stores. J Biol Chem 2010; 285:28912-28923.
53. Watson LM, Chan AK, Berry LR et al. Overexpression of the 78-kDa glucose-regulated protein/immunoglobulin-binding protein (GRP78/BiP) inhibits tissue factor procoagulant activity. J Biol Chem 2003; 278:17438-17447.
54. Li M, Baumeister P, Roy B et al. ATF6 as a Transcription Activator of the Endoplasmic Reticulum Stress Element: Thapsigargin Stress-Induced Changes and Synergistic Interactions with NF-Y and YY1. Mol Cell Biol 2000; 20:5096-5106.
55. Baumeister P, Luo S, Skarnes WC et al. Endoplasmic reticulum stress induction of the Grp78/BiP promoter: activating mechanisms mediated by YY1 and its interactive chromatin modifiers. Mol Cell Biol 2005; 25:4529-4540.
56. Nagy Z, Riss A, Romier C et al. The human SPT20-containing SAGA complex plays a direct role in the regulation of endoplasmic reticulum stress-induced genes. Mol Cell Biol 2009; 29:1649-1660.
57. Roy B, Li WW, Lee AS. Calcium-sensitive transcriptional activation of the proximal CCAAT regulatory element of the grp78/BiP promoter by the human nuclear factor CBF/NF-Y. J Biol Chem 1996; 271:28995-29002.
58. Abdelrahim M, Liu S, Safe S. Induction of endoplasmic reticulum-induced stress genes in Panc-1 pancreatic cancer cells is dependent on Sp proteins. J Biol Chem 2005; 280:16508-16513.
59. Parker R, Phan T, Baumeister P et al. Identification of TFII-I as the endoplasmic reticulum stress response element binding factor ERSF: its autoregulation by stress and interaction with ATF6. Mol Cell Biol 2001; 21:3220-3233.
60. Luo S, Baumeister P, Yang S, Abcouwer SF, Lee AS. Induction of Grp78/BiP by translational block: activation of the Grp78 promoter by ATF4 through and upstream ATF/CRE site independent of the endoplasmic reticulum stress elements. J Biol Chem 2003; 278:37375-37385.
61. Racek T, Buhlmann S, Rust F et al. Transcriptional repression of the prosurvival endoplasmic reticulum chaperone GRP78/BIP by E2F1. J Biol Chem 2008; 283:34305-34314.
62. Baumeister P, Dong D, Fu Y, Lee AS. Transcriptional induction of GRP78/BiP by histone deacetylase inhibitors and resistance to histone deacetylase inhibitor-induced apoptosis. Mol Cancer Ther 2009.
63. Kim SK, Kim YK, Lee AS. Expression of the glucose-regulated proteins (GRP94 and GRP78) in differentiated and undifferentiated mouse embryonic cells and the use of the GRP78 promoter as an expression system in embryonic cells. Differentiation 1990; 42:153-159.
64. Barnes JA, Smoak IW. Glucose-regulated protein 78 (GRP78) is elevated in embryonic mouse heart and induced following hypoglycemic stress. Anat Embryol (Berl) 2000; 202:67-74.
65. Mao C, Tai WC, Bai Y, Poizat C, Lee AS. In vivo regulation of Grp78/BiP transcription in the embryonic heart: role of the endoplasmic reticulum stress response element and GATA-4. J Biol Chem 2006; 281:8877-8887.
66. Macejak DG, Sarnow P. Internal initiation of translation mediated by the 5' leader of a cellular mRNA. Nature 1991; 353:90-94.
67. Yang Q, Sarnow P. Location of the internal ribosome entry site in the 5' non-coding region of the immunoglobulin heavy-chain binding protein (BiP) mRNA: evidence for specific RNA-protein interactions. Nucleic Acids Res 1997; 25:2800-2807.
68. Kim YK, Back SH, Rho J, Lee SH, Jang SK. La autoantigen enhances translation of BiP mRNA. Nucleic Acids Res 2001; 29:5009-5016.
69. Cho S, Park SM, Kim TD et al. BiP internal ribosomal entry site activity is controlled by heat-induced interaction of NSAP1. Mol Cell Biol 2007; 27:368-383.
70. Kim YK, Hahm B, Jang SK. Polypyrimidine tract-binding protein inhibits translation of bip mRNA. J Mol Biol 2000; 304:119-133.
71. Tardif KD, Waris G, Siddiqui A. Hepatitis C virus, ER stress, and oxidative stress. Trends Microbiol 2005; 13:159-163.
72. Pasqual G, Burri DJ, Pasquato A, de la Torre JC, Kunz S. The role of the host cell's unfolded protein response in arenavirus infection. J Virol 2010.
73. Cheng G, Feng Z, He B. Herpes simplex virus 1 infection activates the endoplasmic reticulum resident kinase PERK and mediates eIF-2alpha dephosphorylation by the gamma(1)34.5 protein. J Virol 2005; 79:1379-1388.
74. Isler JA, Skalet AH, Alwine JC. Human cytomegalovirus infection activates and regulates the unfolded protein response. J Virol 2005; 79:6890-6899.
75. Chan CP, Siu KL, Chin KT et al. Modulation of the unfolded protein response by the severe acute respiratory syndrome coronavirus spike protein. J Virol 2006; 80:9279-9287.
76. Yu CY, Hsu YW, Liao CL, Lin YL. Flavivirus infection activates the XBP1 pathway of the unfolded protein response to cope with endoplasmic reticulum stress. J Virol 2006; 80:11868-11880.
77. Su HL, Liao CL, Lin YL. Japanese encephalitis virus infection initiates endoplasmic reticulum stress and an unfolded protein response. J Virol 2002; 76:4162-4171.
78. Medigeshi GR, Lancaster AM, Hirsch AJ et al. West Nile virus infection activates the unfolded protein response, leading to CHOP induction and apoptosis. J Virol 2007; 81:10849-10860.
79. Li XD, Lankinen H, Putkuri N, Vapalahti O, Vaheri A. Tula hantavirus triggers pro-apoptotic signals of ER stress in Vero E6 cells. Virology 2005; 333:180-189.
80. Zhang HM, Ye X, Su Y et al. Coxsackievirus B3 infection activates the unfolded protein response and induces apoptosis through downregulation of p58IPK and activation of CHOP and SREBP1. J Virol 2010; 84:8446-8459.
81. Triantafilou K, Fradelizi D, Wilson K, Triantafilou M. GRP78, a coreceptor for coxsackievirus A9, interacts with major histocompatibility complex class I molecules which mediate virus internalization. J Virol 2002; 76:633-643.
82. Landolfo S, Gariglio M, Gribaudo G, Lembo D. The human cytomegalovirus. Pharmacology & Therapeutics 2003; 98:269-297.
83. Mocaski ES, Shenk T, Pass RF. Cytomegalovirus: Replication. In: Knipe DM, Howley PM. eds. Fields Virology. Philadelphia: Lippincott Williams and Wilkins, 2007:2718-2727.
84. Bissinger AL, Sinzger C, Kaiserling E, Jahn G. Human cytomegalovirus as a direct pathogen: correlation of multiorgan involvement and cell distribution with clinical and pathological findings in a case of congenital inclusion disease. J Med Virol 2002; 67:200-206.
85. Sinzger C, Plachter B, Grefte A, The TH, Jahn G. Tissue macrophages are infected by human cytomegalovirus in vivo. J Infect Dis 1996; 173:240-245.
86. Plachter B, Sinzger C, Jahn G. Cell types involved in replication and distribution of human cytomegalovirus. Adv Virus Res 1996; 46:195-261.
87. Sinzger C, Jahn G. Human cytomegalovirus cell tropism and pathogenesis. Intervirology 1996; 39:302-319.
88. Kahl M, Siegel-Axel D, Stenglein S, Jahn G, Sinzger C. Efficient lytic infection of human arterial endothelial cells by human cytomegalovirus strains. J Virol 2000; 74:7628-7635.
89. Sinzger C, Grefte A, Plachter B et al. Fibroblasts, epithelial cells, endothelial cells and smooth muscle cells are major targets of human cytomegalovirus infection in lung and gastrointestinal tissues. J Gen Virol 1995; 76 ( Pt 4):741-750.
90. Isaacson MK, Feire AL, Compton T. Epidermal growth factor receptor is not required for human cytomegalovirus entry or signaling. J Virol 2007; 81:6241-6247.
91. Wang X, Huong SM, Chiu ML, Raab-Traub N, Huang ES. Epidermal growth factor receptor is a cellular receptor for human cytomegalovirus. Nature 2003; 424:456-461.
92. Compton T. Receptors and immune sensors: the complex entry path of human cytomegalovirus. Trends Cell Biol 2004; 14:5-8.
93. Wang X, Huang DY, Huong SM, Huang ES. Integrin alphavbeta3 is a coreceptor for human cytomegalovirus. Nat Med 2005; 11:515-521.
94. Feire AL, Koss H, Compton T. Cellular integrins function as entry receptors for human cytomegalovirus via a highly conserved disintegrin-like domain. Proc Natl Acad Sci U S A 2004; 101:15470-15475.
95. Feire AL, Roy RM, Manley K, Compton T. The glycoprotein B disintegrin-like domain binds beta 1 integrin to mediate cytomegalovirus entry. J Virol 2010; 84:10026-10037.
96. Nelson JA, Gnann JW, Jr., Ghazal P. Regulation and tissue-specific expression of human cytomegalovirus. Curr Top Microbiol Immunol 1990; 154:75-100.
97. Meier JL, Stinski MF. Effect of a modulator deletion on transcription of the human cytomegalovirus major immediate-early genes in infected undifferentiated and differentiated cells. J Virol 1997; 71:1246-1255.
98. Boshart M, Weber F, Jahn G et al. A very strong enhancer is located upstream of an immediate early gene of human cytomegalovirus. Cell 1985; 41:521-530.
99. Fortunato EA, Spector DH. Regulation of human cytomegalovirus gene expression. Adv Virus Res 1999; 54:61-128.
100. Pajovic S, Wong EL, Black AR, Azizkhan JC. Identification of a viral kinase that phosphorylates specific E2Fs and pocket proteins. Mol Cell Biol 1997; 17:6459-6464.
101. Spengler ML, Kurapatwinski K, Black AR, Azizkhan-Clifford J. SUMO-1 modification of human cytomegalovirus IE1/IE72. J Virol 2002; 76:2990-2996.
102. Gawn JM, Greaves RF. Absence of IE1 p72 protein function during low-multiplicity infection by human cytomegalovirus results in a broad block to viral delayed-early gene expression. J Virol 2002; 76:4441-4455.
103. Greaves RF, Mocarski ES. Defective Growth Correlates with Reduced Accumulation of a Viral DNA Replication Protein after Low-Multiplicity Infection by a Human Cytomegalovirus ie1 Mutant. J Virol 1998; 72:366-379.
104. Reeves M, Woodhall D, Compton T, Sinclair J. Human cytomegalovirus IE72 protein interacts with the transcriptional repressor hDaxx to regulate LUNA gene expression during lytic infection. J Virol 2010; 84:7185-7194.
105. Nevels M, Brune W, Shenk T. SUMOylation of the human cytomegalovirus 72-kilodalton IE1 protein facilitates expression of the 86-kilodalton IE2 protein and promotes viral replication. J Virol 2004; 78:7803-7812.
106. Hagemeier C, Walker SM, Sissons PJ, Sinclair JH. The 72K IE1 and 80K IE2 proteins of human cytomegalovirus independently trans-activate the c-fos, c-myc and hsp70 promoters via basal promoter elements. J Gen Virol 1992; 73 ( Pt 9):2385-2393.
107. Hayhurst GP, Bryant LA, Caswell RC, Walker SM, Sinclair JH. CCAAT box-dependent activation of the TATA-less human DNA polymerase alpha promoter by the human cytomegalovirus 72-kilodalton major immediate-early protein. J Virol 1995; 69:182-188.
108. Margolis MJ, Pajovic S, Wong EL et al. Interaction of the 72-kilodalton human cytomegalovirus IE1 gene product with E2F1 coincides with E2F-dependent activation of dihydrofolate reductase transcription. J Virol 1995; 69:7759-7767.
109. Shirakata M, Terauchi M, Ablikim M et al. Novel immediate-early protein IE19 of human cytomegalovirus activates the origin recognition complex I promoter in a cooperative manner with IE72. J Virol 2002; 76:3158-3167.
110. Wade M, Kowalik TF, Mudryj M, Huang ES, Azizkhan JC. E2F mediates dihydrofolate reductase promoter activation and multiprotein complex formation in human cytomegalovirus infection. Mol Cell Biol 1992; 12:4364-4374.
111. Xu Y, Ahn J-H, Cheng M et al. Proteasome-Independent Disruption of PML Oncogenic Domains (PODs), but Not Covalent Modification by SUMO-1, Is Required for Human Cytomegalovirus Immediate-Early Protein IE1 To Inhibit PML-Mediated Transcriptional Repression. J Virol 2001; 75:10683-10695.
112. Zhang Z, Huong SM, Wang X, Huang DY, Huang ES. Interactions between human cytomegalovirus IE1-72 and cellular p107: functional domains and mechanisms of up-regulation of cyclin E/cdk2 kinase activity. J Virol 2003; 77:12660-12670.
113. Kim S, Yu SS, Lee IS et al. Human cytomegalovirus IE1 protein activates AP-1 through a cellular protein kinase(s). J Gen Virol 1999; 80:961-969.
114. Jiang HY, Petrovas C, Sonenshein GE. RelB-p50 NF-kappa B complexes are selectively induced by cytomegalovirus immediate-early protein 1: differential regulation of Bcl-x(L) promoter activity by NF-kappa B family members. J Virol 2002; 76:5737-5747.
115. Wang X, Sonenshein GE. Induction of the RelB NF-kappaB subunit by the cytomegalovirus IE1 protein is mediated via Jun kinase and c-Jun/Fra-2 AP-1 complexes. J Virol 2005; 79:95-105.
116. Crump JW, Geist LJ, Auron PE et al. The immediate early genes of human cytomegalovirus require only proximal promoter elements to upregulate expression of interleukin-1 beta. Am J Respir Cell Mol Biol 1992; 6:674-677.
117. Iwamoto GK, Monick MM, Clark BD et al. Modulation of interleukin 1 beta gene expression by the immediate early genes of human cytomegalovirus. J Clin Invest 1990; 85:1853-1857.
118. Wara-aswapati N, Yang Z, Waterman WR et al. Cytomegalovirus IE2 protein stimulates interleukin 1beta gene transcription via tethering to Spi-1/PU.1. Mol Cell Biol 1999; 19:6803-6814.
119. Murayama T, Mukaida N, Sadanari H et al. The immediate early gene 1 product of human cytomegalovirus is sufficient for up-regulation of interleukin-8 gene expression. Biochem Biophys Res Commun 2000; 279:298-304.
120. Murayama T, Ohara Y, Obuchi M et al. Human cytomegalovirus induces interleukin-8 production by a human monocytic cell line, THP-1, through acting concurrently on AP-1- and NF-kappaB-binding sites of the interleukin-8 gene. J Virol 1997; 71:5692-5695.
121. Murayama T, Kuno K, Jisaki F et al. Enhancement human cytomegalovirus replication in a human lung fibroblast cell line by interleukin-8. J Virol 1994; 68:7582-7585.
122. Kline JN, Geist LJ, Monick MM, Stinski MF, Hunninghake GW. Regulation of expression of the IL-1 receptor antagonist (IL-1ra) gene by products of the human cytomegalovirus immediate early genes. J Immunol 1994; 152:2351-2357.
123. Chan G, Stinski MF, Guilbert LJ. Human cytomegalovirus-induced upregulation of intercellular cell adhesion molecule-1 on villous syncytiotrophoblasts. Biol Reprod 2004; 71:797-803.
124. Burns LJ, Pooley JC, Walsh DJ et al. Intercellular adhesion molecule-1 expression in endothelial cells is activated by cytomegalovirus immediate early proteins. Transplantation 1999; 67:137-144.
125. Kronschnabl M, Stamminger T. Synergistic induction of intercellular adhesion molecule-1 by the human cytomegalovirus transactivators IE2p86 and pp71 is mediated via an Sp1-binding site. J Gen Virol 2003; 84:61-73.
126. Hwang ES, Zhang Z, Cai H et al. Human cytomegalovirus IE1-72 protein interacts with p53 and inhibits p53-dependent transactivation by a mechanism different from that of IE2-86 protein. J Virol 2009; 83:12388-12398.
127. Ahn JH, Hayward GS. The major immediate-early proteins IE1 and IE2 of human cytomegalovirus colocalize with and disrupt PML-associated nuclear bodies at very early times in infected permissive cells. J Virol 1997; 71:4599-4613.
128. Kelly C, Van Driel R, Wilkinson GW. Disruption of PML-associated nuclear bodies during human cytomegalovirus infection. J Gen Virol 1995; 76 ( Pt 11):2887-2893.
129. Korioth F, Maul GG, Plachter B, Stamminger T, Frey J. The nuclear domain 10 (ND10) is disrupted by the human cytomegalovirus gene product IE1. Exp Cell Res 1996; 229:155-158.
130. Wilkinson GW, Kelly C, Sinclair JH, Rickards C. Disruption of PML-associated nuclear bodies mediated by the human cytomegalovirus major immediate early gene product. J Gen Virol 1998; 79 ( Pt 5):1233-1245.
131. Ishov AM, Stenberg RM, Maul GG. Human cytomegalovirus immediate early interaction with host nuclear structures: definition of an immediate transcript environment. J Cell Biol 1997; 138:5-16.
132. Ahn JH, Brignole EJ, 3rd, Hayward GS. Disruption of PML subnuclear domains by the acidic IE1 protein of human cytomegalovirus is mediated through interaction with PML and may modulate a RING finger-dependent cryptic transactivator function of PML. Mol Cell Biol 1998; 18:4899-4913.
133. Salomoni P, Pandolfi PP. The role of PML in tumor suppression. Cell 2002; 108:165-170.
134. Soroceanu L, Cobbs CS. Is HCMV a tumor promoter? Virus Res 2010.
135. Shen Y, Zhu H, Shenk T. Human cytomagalovirus IE1 and IE2 proteins are mutagenic and mediate "hit-and-run" oncogenic transformation in cooperation with the adenovirus E1A proteins. Proc Natl Acad Sci U S A 1997; 94:3341-3345.
136. Cobbs CS, Soroceanu L, Denham S, Zhang W, Kraus MH. Modulation of oncogenic phenotype in human glioma cells by cytomegalovirus IE1-mediated mitogenicity. Cancer Res 2008; 68:724-730.
137. Cobbs CS, Soroceanu L, Denham S et al. Human cytomegalovirus induces cellular tyrosine kinase signaling and promotes glioma cell invasiveness. J Neurooncol 2007; 85:271-280.
138. Cobbs CS, Harkins L, Samanta M et al. Human Cytomegalovirus Infection and Expression in Human Malignant Glioma. Cancer Res 2002; 62:3347-3350.
139. Straat K, Liu C, Rahbar A et al. Activation of telomerase by human cytomegalovirus. J Natl Cancer Inst 2009; 101:488-497.
140. Blaheta RA, Weich E, Marian D et al. Human cytomegalovirus infection alters PC3 prostate carcinoma cell adhesion to endothelial cells and extracellular matrix. Neoplasia 2006; 8:807-816.
141. Buchkovich NJ, Maguire TG, Paton AW, Paton JC, Alwine JC. The endoplasmic reticulum chaperone BiP/GRP78 is important in the structure and function of the HCMV assembly compartment. J Virol 2009.
142. Buchkovich NJ, Maguire TG, Alwine JC. Role of the endoplasmic reticulum chaperone BiP, SUN domain proteins, and dynein in altering nuclear morphology during human cytomegalovirus infection. J Virol 2010; 84:7005-7017.
143. Buchkovich NJ, Yu Y, Pierciey FJ, Jr., Alwine JC. HCMV induces the endoplasmic reticulum chaperone BiP through increased transcription and activation of translation using the BiP IRES. J Virol 2010.
144. Spaete RR, Mocarski ES. Insertion and deletion mutagenesis of the human cytomegalovirus genome. Proc Natl Acad Sci U S A 1987; 84:7213-7217.
145. Hsu CH, Chang MD, Tai KY et al. HCMV IE2-mediated inhibition of HAT activity downregulates p53 function. EMBO J 2004; 23:2269-2280.
146. Lee H-R, Kim D-J, Lee J-M et al. Ability of the Human Cytomegalovirus IE1 Protein To Modulate Sumoylation of PML Correlates with Its Functional Activities in Transcriptional Regulation and Infectivity in Cultured Fibroblast Cells. J Virol 2004; 78:6527-6542.
147. Juan L-J, Shia W-J, Chen M-H et al. Histone Deacetylases Specifically Down-regulate p53-dependent Gene Activation. J Biol Chem 2000; 275:20436-20443.
148. Hwang S, Gou Z, Kuznetsov IB. DP-Bind: a web server for sequence-based prediction of DNA-binding residues in DNA-binding proteins. Bioinformatics 2007; 23:634-636.
149. Kuznetsov IB, Gou Z, Li R, Hwang S. Using evolutionary and structural information to predict DNA-binding sites on DNA-binding proteins. Proteins 2006; 64:19-27.
150. Lukac DM, Harel NY, Tanese N, Alwine JC. TAF-like functions of human cytomegalovirus immediate-early proteins. J Virol 1997; 71:7227-7239.
151. Mizzen CA, Yang X-J, Kokubo T et al. The TAFII250 Subunit of TFIID Has Histone Acetyltransferase Activity. Cell 1996; 87:1261-1270.
152. Buchkovich NJ, Maguire TG, Yu Y et al. Human cytomegalovirus specifically controls the levels of the endoplasmic reticulum chaperone BiP/GRP78, which is required for virion assembly. J Virol 2008; 82:31-39.
153. Johnson RA, Yurochko AD, Poma EE, Zhu L, Huang ES. Domain mapping of the human cytomegalovirus IE1-72 and cellular p107 protein--protein interaction and the possible functional consequences. J Gen Virol 1999; 80:1293-1303.
154. Poma EE, Kowalik TF, Zhu L, Sinclair JH, Huang ES. The human cytomegalovirus IE1-72 protein interacts with the cellular p107 protein and relieves p107-mediated transcriptional repression of an E2F-responsive promoter. J Virol 1996; 70:7867-7877.
155. Huh YH, Kim YE, Kim ET et al. Binding STAT2 by the acidic domain of human cytomegalovirus IE1 promotes viral growth and is negatively regulated by SUMO. J Virol 2008; 82:10444-10454.
156. Nevels M, Paulus C, Shenk T. Human cytomegalovirus immediate-early 1 protein facilitates viral replication by antagonizing histone deacetylation. Proc Natl Acad Sci U S A 2004; 101:17234-17239.
157. Yurochko AD, Mayo MW, Poma EE, Baldwin AS, Jr., Huang ES. Induction of the transcription factor Sp1 during human cytomegalovirus infection mediates upregulation of the p65 and p105/p50 NF-kappaB promoters. J Virol 1997; 71:4638-4648.
158. Cherrington JM, Khoury EL, Mocarski ES. Human cytomegalovirus ie2 negatively regulates alpha gene expression via a short target sequence near the transcription start site. J Virol 1991; 65:887-896.
159. Jupp R, Hoffmann S, Depto A et al. Direct interaction of the human cytomegalovirus IE86 protein with the cis repression signal does not preclude TBP from binding to the TATA box. J Virol 1993; 67:5595-5604.
160. Wang L, Brown SJ. BindN: a web-based tool for efficient prediction of DNA and RNA binding sites in amino acid sequences. Nucleic Acids Res 2006; 34:W243-248.
161. Wang L, Huang C, Yang MQ, Yang JY. BindN+ for accurate prediction of DNA and RNA-binding residues from protein sequence features. BMC Syst Biol 2010; 4 Suppl 1:S3.
162. Yan C, Terribilini M, Wu F et al. Predicting DNA-binding sites of proteins from amino acid sequence. BMC Bioinformatics 2006; 7:262.
163. Johnson DS, Mortazavi A, Myers RM, Wold B. Genome-wide mapping of in vivo protein-DNA interactions. Science 2007; 316:1497-1502.
164. Jothi R, Cuddapah S, Barski A, Cui K, Zhao K. Genome-wide identification of in vivo protein-DNA binding sites from ChIP-Seq data. Nucleic Acids Res 2008; 36:5221-5231.
165. Das S, Vasanji A, Pellett PE. Three-dimensional structure of the human cytomegalovirus cytoplasmic virion assembly complex includes a reoriented secretory apparatus. J Virol 2007; 81:11861-11869.
166. Kardosh A, Golden EB, Pyrko P et al. Aggravated Endoplasmic Reticulum Stress as a Basis for Enhanced Glioblastoma Cell Killing by Bortezomib in Combination with Celecoxib or Its Non-Coxib Analogue, 2,5-Dimethyl-Celecoxib. Cancer Res 2008; 68:843-851.
167. Pyrko P, Schonthal AH, Hofman FM, Chen TC, Lee AS. The Unfolded Protein Response Regulator GRP78/BiP as a Novel Target for Increasing Chemosensitivity in Malignant Gliomas. Cancer Res 2007; 67:9809-9816.
168. Lee SB, Ou DS, Lee CF, Juan LJ. Gene-specific transcriptional activation mediated by the p150 subunit of the chromatin assembly factor 1. J Biol Chem 2009; 284:14040-14049.
169. Lee CF, Ou DS, Lee SB et al. hNaa10p contributes to tumorigenesis by facilitating DNMT1-mediated tumor suppressor gene silencing. J Clin Invest 2010; 120:2920-2930.
170. Kuo HP, Lee DF, Chen CT et al. ARD1 stabilization of TSC2 suppresses tumorigenesis through the mTOR signaling pathway. Sci Signal 2010; 3:ra9.
171. Lee DY, Sugden B. The LMP1 oncogene of EBV activates PERK and the unfolded protein response to drive its own synthesis. Blood 2008; 111:2280-2289.
172. Xu A, Bellamy AR, Taylor JA. BiP (GRP78) and endoplasmin (GRP94) are induced following rotavirus infection and bind transiently to an endoplasmic reticulum-localized virion component. J Virol 1998; 72:9865-9872.
173. Bechill J, Chen Z, Brewer JW, Baker SC. Coronavirus infection modulates the unfolded protein response and mediates sustained translational repression. J Virol 2008; 82:4492-4501.
174. Jordan R, Wang L, Graczyk TM, Block TM, Romano PR. Replication of a cytopathic strain of bovine viral diarrhea virus activates PERK and induces endoplasmic reticulum stress-mediated apoptosis of MDBK cells. J Virol 2002; 76:9588-9599.
175. Wati S, Soo ML, Zilm P et al. Dengue virus infection induces upregulation of GRP78, which acts to chaperone viral antigen production. J Virol 2009; 83:12871-12880.
176. Jheng JR, Lau KS, Tang WF, Wu MS, Horng JT. Endoplasmic reticulum stress is induced and modulated by enterovirus 71. Cell Microbiol 2010; 12:796-813.
177. Barry G, Fragkoudis R, Ferguson MC et al. Semliki forest virus-induced endoplasmic reticulum stress accelerates apoptotic death of mammalian cells. J Virol 2010; 84:7369-7377.
178. Watowich SS, Morimoto RI, Lamb RA. Flux of the paramyxovirus hemagglutinin-neuraminidase glycoprotein through the endoplasmic reticulum activates transcription of the GRP78-BiP gene. J Virol 1991; 65:3590-3597.
179. Bolt G. The measles virus (MV) glycoproteins interact with cellular chaperones in the endoplasmic reticulum and MV infection upregulates chaperone expression. Arch Virol 2001; 146:2055-2068.
180. Bitko V, Barik S. An endoplasmic reticulum-specific stress-activated caspase (caspase-12) is implicated in the apoptosis of A549 epithelial cells by respiratory syncytial virus. J Cell Biochem 2001; 80:441-454.
181. Li B, Gao B, Ye L et al. Hepatitis B virus X protein (HBx) activates ATF6 and IRE1-XBP1 pathways of unfolded protein response. Virus Res 2007; 124:44-49.
182. Cherrington JM, Mocarski ES. Human cytomegalovirus ie1 transactivates the alpha promoter-enhancer via an 18-base-pair repeat element. J Virol 1989; 63:1435-1440.
183. Gribaudo G, Riera L, Rudge TL et al. Human cytomegalovirus infection induces cellular thymidylate synthase gene expression in quiescent fibroblasts. J Gen Virol 2002; 83:2983-2993.
184. Geist LJ, Dai LY. Cytomegalovirus modulates interleukin-6 gene expression. Transplantation 1996; 62:653-658.
185. Santomenna LD, Colberg-Poley AM. Induction of cellular hsp70 expression by human cytomegalovirus. J Virol 1990; 64:2033-2040.
186. Krauss S, Kaps J, Czech N, Paulus C, Nevels M. Physical requirements and functional consequences of complex formation between the cytomegalovirus IE1 protein and human STAT2. J Virol 2009; 83:12854-12870.