0 5 Human human JJ 6 12 T-cell T-cell NNP 13 21 leukemia leukemia NN 22 27 virus virus NN 28 32 type type NN 33 34 I i CD 35 38 Tax Tax NNP 39 49 activation activation NN 50 52 of of IN 53 61 NF-kappa NF-kappa NNP 62 67 B/Rel B/Rel NNP 68 76 involves involve VBZ 77 92 phosphorylation phosphorylation NN 93 96 and and CC 97 108 degradation degradation NN 109 111 of of IN 112 113 I i NN 114 119 kappa kappa NN 120 121 B B NNP 122 127 alpha alpha NN 128 131 and and CC 132 136 RelA RelA NNP 137 138 ( ( ( 138 151 p65)-mediated p65)-mediated JJ 152 161 induction induction NN 162 164 of of IN 165 168 the the DT 169 174 c-rel c-rel NN 175 179 gene gene NN 179 180 . . . 182 185 The the DT 186 189 tax tax NN 190 194 gene gene NN 195 202 product product NN 203 205 of of IN 206 211 human human JJ 212 218 T-cell t-cell NN 219 227 leukemia leukemia NN 228 233 virus virus NN 234 238 type type NN 239 240 I i CD 241 242 ( ( ( 242 248 HTLV-I HTLV-I NNP 248 249 ) ) ) 250 252 is be VBZ 253 254 a a DT 255 261 potent potent JJ 262 277 transcriptional transcriptional JJ 278 287 activator activator NN 288 292 that that WDT 293 297 both both CC 298 308 stimulates stimulate VBZ 309 314 viral viral JJ 315 319 gene gene NN 320 330 expression expression NN 331 334 and and CC 335 344 activates activate VBZ 345 347 an an DT 348 353 array array NN 354 356 of of IN 357 365 cellular cellular JJ 366 371 genes gene NNS 372 380 involved involve VBN 381 383 in in IN 384 390 T-cell t-cell NN 391 397 growth growth NN 397 398 . . . 399 402 Tax Tax NNP 403 407 acts act VBZ 408 418 indirectly indirectly RB 419 421 by by IN 422 430 inducing induce VBG 431 433 or or CC 434 443 modifying modify VBG 444 447 the the DT 448 454 action action NN 455 457 of of IN 458 465 various various JJ 466 470 host host NN 471 484 transcription transcription NN 485 492 factors factor NNS 492 493 , , , 494 503 including include VBG 504 511 members member NNS 512 514 of of IN 515 518 the the DT 519 527 NF-kappa NF-kappa NNP 528 533 B/Rel B/Rel NNP 534 540 family family NN 541 543 of of IN 544 560 enhancer-binding enhancer-binding JJ 561 569 proteins protein NNS 569 570 . . . 571 573 In in IN 574 581 resting rest VBG 582 583 T t NN 584 589 cells cell NNS 589 590 , , , 591 595 many many JJ 596 598 of of IN 599 604 these these DT 605 613 NF-kappa NF-kappa NNP 614 619 B/Rel B/Rel NNP 620 627 factors factor NNS 628 631 are be VBP 632 643 sequestered sequester VBN 644 646 in in IN 647 650 the the DT 651 660 cytoplasm cytoplasm NN 661 663 by by IN 664 671 various various JJ 672 684 ankyrin-rich ankyrin-rich JJ 685 695 inhibitory inhibitory JJ 696 704 proteins protein NNS 704 705 , , , 706 715 including include VBG 716 717 I i NN 718 723 kappa kappa NN 724 725 B B NNP 726 731 alpha alpha NN 731 732 . . . 733 739 HTLV-I HTLV-I NNP 740 743 Tax Tax NNP 744 754 expression expression NN 755 760 leads lead VBZ 761 763 to to TO 764 767 the the DT 768 780 constitutive constitutive JJ 781 788 nuclear nuclear JJ 789 799 expression expression NN 800 802 of of IN 803 815 biologically biologically RB 816 822 active active JJ 823 831 NF-kappa NF-kappa NNP 832 833 B B NNP 834 837 and and CC 838 843 c-Rel c-rel NN 844 853 complexes complex NNS 853 854 ; ; : 855 862 however however RB 862 863 , , , 864 867 the the DT 868 879 biochemical biochemical JJ 880 892 mechanism(s) mechanism(s) NN 893 903 underlying underlie VBG 904 908 this this DT 909 917 response response NN 918 925 remains remain VBZ 926 932 poorly poorly RB 933 943 understood understand VBN 943 944 . . . 945 947 In in IN 948 952 this this DT 953 958 study study NN 958 959 , , , 960 962 we we PRP 963 974 demonstrate demonstrate VBP 975 979 that that IN 980 994 Tax-stimulated tax-stimulated JJ 995 1002 nuclear nuclear JJ 1003 1013 expression expression NN 1014 1016 of of IN 1017 1025 NF-kappa NF-kappa NNP 1026 1027 B B NNP 1028 1030 in in IN 1031 1035 both both CC 1036 1051 HTLV-I-infected htlv-i-infected JJ 1052 1055 and and CC 1056 1071 Tax-transfected tax-transfected JJ 1072 1077 human human JJ 1078 1079 T t NN 1080 1085 cells cell NNS 1086 1088 is be VBZ 1089 1099 associated associate VBN 1100 1104 with with IN 1105 1108 the the DT 1109 1124 phosphorylation phosphorylation NN 1125 1128 and and CC 1129 1134 rapid rapid JJ 1135 1146 proteolytic proteolytic JJ 1147 1158 degradation degradation NN 1159 1161 of of IN 1162 1163 I i NN 1164 1169 kappa kappa NN 1170 1171 B B NNP 1172 1177 alpha alpha NN 1177 1178 . . . 1179 1181 In in IN 1182 1190 contrast contrast NN 1191 1193 to to TO 1194 1199 prior prior JJ 1200 1202 in in FW 1203 1208 vitro vitro FW 1209 1216 studies study NNS 1216 1217 , , , 1218 1220 at at IN 1221 1226 least least JJS 1227 1228 a a DT 1229 1237 fraction fraction NN 1238 1240 of of IN 1241 1244 the the DT 1245 1259 phosphorylated phosphorylated JJ 1260 1264 form form NN 1265 1267 of of IN 1268 1269 I i NN 1270 1275 kappa kappa NN 1276 1277 B B NNP 1278 1283 alpha alpha NN 1284 1291 remains remain VBZ 1292 1302 physically physically RB 1303 1313 associated associate VBN 1314 1318 with with IN 1319 1322 the the DT 1323 1331 NF-kappa NF-kappa NNP 1332 1333 B B NNP 1334 1341 complex complex NN 1342 1344 in in FW 1345 1349 vivo vivo FW 1350 1353 but but CC 1354 1356 is be VBZ 1357 1364 subject subject JJ 1365 1367 to to TO 1368 1373 rapid rapid JJ 1374 1385 degradation degradation NN 1385 1386 , , , 1387 1394 thereby thereby RB 1395 1404 promoting promote VBG 1405 1408 the the DT 1409 1416 nuclear nuclear JJ 1417 1430 translocation translocation NN 1431 1433 of of IN 1434 1437 the the DT 1438 1444 active active JJ 1445 1453 NF-kappa NF-kappa NNP 1454 1455 B B NNP 1456 1463 complex complex NN 1463 1464 . . . 1465 1467 We we PRP 1468 1475 further further RB 1476 1487 demonstrate demonstrate VBP 1488 1492 that that IN 1493 1496 Tax Tax NNP 1497 1506 induction induction NN 1507 1509 of of IN 1510 1517 nuclear nuclear JJ 1518 1523 c-Rel c-rel NN 1524 1534 expression expression NN 1535 1537 is be VBZ 1538 1547 activated activate VBN 1548 1550 by by IN 1551 1554 the the DT 1555 1559 RelA RelA NNP 1560 1561 ( ( ( 1561 1564 p65 p65 NN 1564 1565 ) ) ) 1566 1573 subunit subunit NN 1574 1576 of of IN 1577 1585 NF-kappa NF-kappa NNP 1586 1587 B B NNP 1587 1588 , , , 1589 1594 which which WDT 1595 1604 activates activate VBZ 1605 1618 transcription transcription NN 1619 1621 of of IN 1622 1625 the the DT 1626 1631 c-rel c-rel NN 1632 1636 gene gene NN 1637 1644 through through IN 1645 1647 an an DT 1648 1657 intrinsic intrinsic JJ 1658 1663 kappa kappa NN 1664 1665 B B NNP 1666 1674 enhancer enhancer NN 1675 1682 element element NN 1682 1683 . . . 1684 1686 In in IN 1687 1693 normal normal JJ 1694 1699 cells cell NNS 1699 1700 , , , 1701 1704 the the DT 1705 1715 subsequent subsequent JJ 1716 1728 accumulation accumulation NN 1729 1731 of of IN 1732 1739 nuclear nuclear JJ 1740 1745 c-Rel c-rel NN 1746 1750 acts act VBZ 1751 1753 to to TO 1754 1761 inhibit inhibit VB 1762 1765 its its PRP$ 1766 1769 own own JJ 1770 1779 continued continued JJ 1780 1790 production production NN 1790 1791 , , , 1792 1802 indicating indicate VBG 1803 1806 the the DT 1807 1815 presence presence NN 1816 1818 of of IN 1819 1821 an an DT 1822 1836 autoregulatory autoregulatory JJ 1837 1841 loop loop NN 1841 1842 . . . 1843 1844 ( ( ( 1844 1852 ABSTRACT abstract NN 1853 1862 TRUNCATED truncated VBN 1863 1865 AT at IN 1866 1869 250 250 CD 1870 1875 WORDS words NNS 1875 1876 ) ) )