0 3 The the DT 4 18 retinoblastoma retinoblastoma NN 19 23 gene gene NN 24 31 product product NN 32 42 negatively negatively RB 43 52 regulates regulate VBZ 53 68 transcriptional transcriptional JJ 69 79 activation activation NN 80 88 mediated mediate VBN 89 91 by by IN 92 95 the the DT 96 101 human human JJ 102 117 cytomegalovirus cytomegalovirus NN 118 121 IE2 ie2 NN 122 129 protein protein NN 129 130 . . . 132 135 The the DT 136 139 IE2 ie2 NN 140 144 gene gene NN 145 152 product product NN 153 155 of of IN 156 161 human human JJ 162 177 cytomegalovirus cytomegalovirus NN 178 179 ( ( ( 179 183 HCMV HCMV NNP 183 184 ) ) ) 185 187 is be VBZ 188 191 one one CD 192 194 of of IN 195 196 a a DT 197 200 few few JJ 201 206 viral viral JJ 207 217 regulatory regulatory JJ 218 226 proteins protein NNS 227 236 expressed express VBN 237 248 immediately immediately RB 249 253 upon upon IN 254 263 infection infection NN 264 266 of of IN 267 270 the the DT 271 275 host host NN 276 280 cell cell NN 280 281 . . . 282 284 It it PRP 285 287 is be VBZ 288 289 a a DT 290 296 potent potent JJ 297 312 transcriptional transcriptional JJ 313 322 activator activator NN 323 325 of of IN 326 330 many many JJ 331 336 viral viral JJ 337 340 and and CC 341 349 cellular cellular JJ 350 359 promoters promoter NNS 359 360 . . . 361 363 We we PRP 364 369 found find VBD 370 374 that that IN 375 378 the the DT 379 393 retinoblastoma retinoblastoma NN 394 408 susceptibility susceptibility NN 409 413 gene gene NN 414 421 product product NN 422 423 ( ( ( 423 425 Rb Rb NNP 425 426 ) ) ) 427 439 dramatically dramatically RB 440 450 suppressed suppress VBD 451 455 this this DT 456 459 IE2 ie2 NN 460 475 transactivation transactivation NN 476 478 of of IN 479 486 various various JJ 487 496 promoters promoter NNS 496 497 . . . 498 505 However however RB 505 506 , , , 507 513 unlike unlike IN 514 521 another another DT 522 527 tumor tumor NN 528 538 suppressor suppressor NN 539 546 protein protein NN 546 547 , , , 548 551 p53 p53 NN 551 552 , , , 553 555 Rb Rb NNP 556 559 did do VBD 560 563 not not RB 564 568 have have VB 569 572 any any DT 573 584 significant significant JJ 585 591 effect effect NN 592 594 on on IN 595 600 basal basal JJ 601 607 levels level NNS 608 610 of of IN 611 624 transcription transcription NN 624 625 , , , 626 636 suggesting suggest VBG 637 641 that that IN 642 644 Rb Rb NNP 645 657 specifically specifically RB 658 667 interacts interact VBZ 668 672 with with IN 673 676 IE2 ie2 NN 677 683 rather rather RB 684 688 than than IN 689 694 other other JJ 695 703 cellular cellular JJ 704 711 factors factor NNS 712 720 involved involve VBN 721 723 in in IN 724 727 the the DT 728 735 general general JJ 736 749 transcription transcription NN 750 759 machinery machinery NN 759 760 . . . 761 763 We we PRP 764 769 found find VBD 770 772 by by IN 773 789 protein-affinity protein-affinity JJ 790 804 chromatography chromatography NN 805 809 that that IN 810 812 Rb Rb NNP 813 815 in in IN 816 823 nuclear nuclear JJ 824 832 extracts extract NNS 833 835 or or CC 836 844 produced produce VBN 845 847 by by IN 848 850 in in FW 851 856 vitro vitro FW 857 868 translation translation NN 869 877 directly directly RB 878 883 bound bind VBD 884 886 to to TO 887 890 IE2 ie2 NN 890 891 . . . 892 895 Our our PRP$ 896 903 results result NNS 904 911 suggest suggest VBP 912 916 that that IN 917 919 Rb Rb NNP 920 923 may may MD 924 932 regulate regulate VB 933 936 the the DT 937 941 life life NN 942 947 cycle cycle NN 948 950 of of IN 951 955 HCMV HCMV NNP 955 956 , , , 957 962 which which WDT 963 965 is be VBZ 966 973 endemic endemic JJ 974 976 in in IN 977 980 the the DT 981 986 human human JJ 987 997 population population NN 997 998 . . . 999 1010 Furthermore furthermore RB 1010 1011 , , , 1012 1017 these these DT 1018 1022 data datum NNS 1023 1026 may may MD 1027 1034 provide provide VB 1035 1038 new new JJ 1039 1047 insights insight NNS 1048 1052 into into IN 1053 1056 the the DT 1057 1061 slow slow JJ 1062 1066 rate rate NN 1067 1069 of of IN 1070 1074 HCMV HCMV NNP 1075 1078 DNA DNA NNP 1079 1090 replication replication NN 1091 1093 in in IN 1094 1099 cells cell NNS 1100 1103 and and CC 1104 1107 the the DT 1108 1116 possible possible JJ 1117 1128 involvement involvement NN 1129 1131 of of IN 1132 1136 HCMV HCMV NNP 1137 1139 in in IN 1140 1153 tumorigenesis tumorigenesis NN 1153 1154 . . .