0 1 A a DT 2 7 novel novel JJ 8 18 interferon interferon NN 19 29 regulatory regulatory JJ 30 36 factor factor NN 37 43 family family NN 44 57 transcription transcription NN 58 64 factor factor NN 64 65 , , , 66 81 ICSAT/Pip/LSIRF ICSAT/Pip/LSIRF NNP 81 82 , , , 83 87 that that WDT 88 98 negatively negatively RB 99 108 regulates regulate VBZ 109 112 the the DT 113 121 activity activity NN 122 124 of of IN 125 145 interferon-regulated interferon-regulated JJ 146 151 genes gene NNS 151 152 . . . 154 156 We we PRP 157 161 have have VBP 162 170 isolated isolate VBN 171 172 a a DT 173 178 novel novel JJ 179 183 cDNA cdna NN 184 189 clone clone NN 190 198 encoding encode VBG 199 209 interferon interferon NN 210 211 ( ( ( 211 214 IFN IFN NNP 214 215 ) ) ) 216 225 consensus consensus NN 226 242 sequence-binding sequence-binding JJ 243 250 protein protein NN 251 253 in in IN 254 259 adult adult JJ 260 266 T-cell t-cell NN 267 275 leukemia leukemia NN 276 280 cell cell NN 281 285 line line NN 286 288 or or CC 289 298 activated activate VBN 299 300 T t NN 301 306 cells cell NNS 307 308 ( ( ( 308 313 ICSAT ICSAT NNP 313 314 ) ) ) 314 315 ; ; : 316 320 this this DT 321 328 protein protein NN 329 331 is be VBZ 332 335 the the DT 336 341 human human JJ 342 349 homolog homolog NN 350 352 of of IN 353 356 the the DT 357 365 recently recently RB 366 372 cloned clone VBN 373 382 Pip/LSIRF Pip/LSIRF NNP 382 383 . . . 384 389 ICSAT icsat NN 390 392 is be VBZ 393 405 structurally structurally RB 406 410 most most RBS 411 418 closely closely RB 419 426 related related JJ 427 429 to to TO 430 433 the the DT 434 444 previously previously RB 445 451 cloned clone VBN 452 457 ICSBP ICSBP NNP 457 458 , , , 459 460 a a DT 461 467 member member NN 468 470 of of IN 471 474 the the DT 475 478 IFN IFN NNP 479 489 regulatory regulatory JJ 490 496 factor factor NN 497 498 ( ( ( 498 501 IRF IRF NNP 501 502 ) ) ) 503 509 family family NN 510 512 of of IN 513 521 proteins protein NNS 522 526 that that WDT 527 532 binds bind VBZ 533 535 to to TO 536 546 interferon interferon NN 547 556 consensus consensus NN 557 566 sequences sequence NNS 567 568 ( ( ( 568 572 ICSs ICS NNP 572 573 ) ) ) 574 579 found find VBN 580 582 in in IN 583 587 many many JJ 588 597 promoters promoter NNS 598 600 of of IN 601 604 the the DT 605 618 IFN-regulated ifn-regulated JJ 619 624 genes gene NNS 624 625 . . . 626 631 Among among IN 632 638 T-cell t-cell NN 639 644 lines line NNS 645 657 investigated investigate VBN 657 658 , , , 659 664 ICSAT ICSAT NNP 665 668 was be VBD 669 679 abundantly abundantly RB 680 689 expressed express VBN 690 692 in in IN 693 698 human human JJ 699 705 T-cell t-cell NN 706 714 leukemia leukemia NN 715 720 virus virus NN 721 725 type type NN 726 727 1 1 CD 728 729 ( ( ( 729 745 HTLV-1)-infected htlv-1)-infected JJ 746 747 T t NN 748 753 cells cell NNS 753 754 . . . 755 759 When when WRB 760 763 the the DT 764 770 HTLV-1 htlv-1 NN 771 774 tax tax NN 775 779 gene gene NN 780 783 was be VBD 784 793 expressed express VBN 794 796 or or CC 797 804 phorbol phorbol NN 805 814 myristake myristake NN 815 829 acetate-A23187 acetate-a23187 NN 830 841 stimulation stimulation NN 842 845 was be VBD 846 850 used use VBN 850 851 , , , 852 857 ICSAT ICSAT NNP 858 868 expression expression NN 869 872 was be VBD 873 880 induced induce VBN 881 883 in in IN 884 890 Jurkat Jurkat NNP 891 896 cells cell NNS 897 902 which which WDT 903 912 otherwise otherwise RB 913 915 do do VBP 916 919 not not RB 920 927 express express VB 928 933 ICSAT ICSAT NNP 933 934 . . . 935 939 When when WRB 940 943 the the DT 944 951 binding binding NN 952 954 of of IN 955 960 ICSAT ICSAT NNP 961 963 to to TO 964 968 four four CD 969 978 different different JJ 979 983 ICSs ics NNS 984 987 was be VBD 988 994 tested test VBN 994 995 , , , 996 999 the the DT 1000 1008 relative relative JJ 1009 1020 differences difference NNS 1021 1023 in in IN 1024 1031 binding binding NN 1032 1042 affinities affinity NNS 1043 1046 for for IN 1047 1052 those those DT 1053 1057 ICSs ics NNS 1058 1062 were be VBD 1063 1073 determined determine VBN 1073 1074 . . . 1075 1077 To to TO 1078 1083 study study VB 1084 1087 the the DT 1088 1098 functional functional JJ 1099 1103 role role NN 1104 1106 of of IN 1107 1112 ICSAT ICSAT NNP 1112 1113 , , , 1114 1116 we we PRP 1117 1126 performed perform VBD 1127 1141 cotransfection cotransfection NN 1142 1153 experiments experiment NNS 1154 1158 with with IN 1159 1162 the the DT 1163 1168 human human JJ 1169 1178 embryonal embryonal JJ 1179 1188 carcinoma carcinoma NN 1189 1193 cell cell NN 1194 1198 line line NN 1199 1206 N-Tera2 n-tera2 NN 1206 1207 . . . 1208 1213 ICSAT icsat NN 1214 1217 was be VBD 1218 1230 demonstrated demonstrate VBN 1231 1233 to to TO 1234 1241 possess possess VB 1242 1252 repressive repressive JJ 1253 1261 function function NN 1262 1266 over over IN 1267 1270 the the DT 1271 1275 gene gene NN 1276 1286 activation activation NN 1287 1294 induced induce VBN 1295 1297 by by IN 1298 1301 IFN ifn NN 1302 1313 stimulation stimulation NN 1314 1316 or or CC 1317 1319 by by IN 1320 1325 IRF-1 irf-1 NN 1326 1340 cotransfection cotransfection NN 1340 1341 . . . 1342 1346 Such such JJ 1347 1357 repressive repressive JJ 1358 1366 function function NN 1367 1369 is be VBZ 1370 1377 similar similar JJ 1378 1380 to to TO 1381 1385 that that DT 1386 1390 seen see VBN 1391 1393 in in IN 1394 1399 IRF-2 IRF-2 NNP 1400 1402 or or CC 1403 1408 ICSBP ICSBP NNP 1408 1409 . . . 1410 1417 However however RB 1417 1418 , , , 1419 1421 we we PRP 1422 1426 have have VBP 1427 1432 found find VBN 1433 1437 that that IN 1438 1443 ICSAT ICSAT NNP 1444 1447 has have VBZ 1448 1449 a a DT 1450 1459 different different JJ 1460 1470 repressive repressive JJ 1471 1477 effect effect NN 1478 1482 from from IN 1483 1487 that that DT 1488 1490 of of IN 1491 1496 IRF-2 IRF-2 NNP 1497 1499 or or CC 1500 1505 ICSBP ICSBP NNP 1506 1508 in in IN 1509 1513 some some DT 1514 1528 IFN-responsive ifn-responsive JJ 1529 1537 reporter reporter NN 1538 1548 constructs construct NNS 1548 1549 . . . 1550 1555 These these DT 1556 1563 results result NNS 1564 1571 suggest suggest VBP 1572 1576 that that IN 1577 1578 a a DT 1579 1584 novel novel JJ 1585 1594 mechanism mechanism NN 1595 1597 of of IN 1598 1602 gene gene NN 1603 1613 regulation regulation NN 1614 1616 by by IN 1617 1618 “ `` `` 1618 1630 differential differential JJ 1631 1641 repression repression NN 1641 1642 ” '' '' 1643 1645 is be VBZ 1646 1650 used use VBN 1651 1653 by by IN 1654 1662 multiple multiple JJ 1663 1670 members member NNS 1671 1673 of of IN 1674 1683 repressor repressor NN 1684 1692 proteins protein NNS 1693 1697 with with IN 1698 1707 different different JJ 1708 1718 repressive repressive JJ 1719 1726 effects effect NNS 1727 1729 on on IN 1730 1733 the the DT 1734 1748 IFN-responsive ifn-responsive JJ 1749 1754 genes gene NNS 1754 1755 . . .