0 10 Activation Activation NNP 11 13 of of IN 14 17 the the DT 18 23 HIV-1 HIV-1 NNP 24 32 enhancer enhancer NN 33 35 by by IN 36 39 the the DT 40 45 LEF-1 lef-1 NN 46 49 HMG HMG NNP 50 57 protein protein NN 58 60 on on IN 61 81 nucleosome-assembled nucleosome-assembled JJ 82 85 DNA dna NN 86 88 in in FW 89 94 vitro vitro FW 94 95 . . . 97 105 Lymphoid lymphoid JJ 106 122 enhancer-binding enhancer-binding JJ 123 129 factor factor NN 130 131 1 1 CD 132 133 ( ( ( 133 138 LEF-1 lef-1 NN 138 139 ) ) ) 140 142 is be VBZ 143 144 a a DT 145 155 regulatory regulatory JJ 156 160 high high JJ 161 169 mobility mobility NN 170 175 group group NN 176 177 ( ( ( 177 180 HMG HMG NNP 180 181 ) ) ) 182 189 protein protein NN 190 194 that that WDT 195 204 activates activate VBZ 205 208 the the DT 209 210 T t NN 211 215 cell cell NN 216 224 receptor receptor NN 225 230 alpha alpha NN 231 232 ( ( ( 232 235 TCR TCR NNP 236 241 alpha alpha NN 241 242 ) ) ) 243 251 enhancer enhancer NN 252 254 in in IN 255 256 a a DT 257 275 context-restricted context-restricted JJ 276 282 manner manner NN 283 285 in in IN 286 287 T t NN 288 293 cells cell NNS 293 294 . . . 295 297 In in IN 298 302 this this DT 303 308 paper paper NN 309 311 we we PRP 312 323 demonstrate demonstrate VBP 324 328 that that IN 329 332 the the DT 333 339 distal distal JJ 340 346 region region NN 347 349 of of IN 350 353 the the DT 354 359 human human JJ 360 376 immunodeficiency immunodeficiency NN 377 384 virus-1 virus-1 NN 385 386 ( ( ( 386 391 HIV-1 HIV-1 NNP 391 392 ) ) ) 393 401 enhancer enhancer NN 401 402 , , , 403 408 which which WDT 409 417 contains contain VBZ 418 429 DNA-binding dna-binding JJ 430 435 sites site NNS 436 439 for for IN 440 445 LEF-1 lef-1 NN 446 449 and and CC 450 455 Ets-1 ets-1 NN 455 456 , , , 457 461 also also RB 462 470 provides provide VBZ 471 472 a a DT 473 483 functional functional JJ 484 491 context context NN 492 495 for for IN 496 506 activation activation NN 507 509 by by IN 510 515 LEF-1 lef-1 NN 515 516 . . . 517 522 First first RB 522 523 , , , 524 526 we we PRP 527 531 show show VBP 532 536 that that IN 537 546 mutations mutation NNS 547 549 in in IN 550 553 the the DT 554 567 LEF-1-binding lef-1-binding JJ 568 572 site site NN 573 580 inhibit inhibit VBP 581 584 the the DT 585 593 activity activity NN 594 596 of of IN 597 609 multimerized multimerized JJ 610 616 copies copy NNS 617 619 of of IN 620 623 the the DT 624 629 HIV-1 HIV-1 NNP 630 638 enhancer enhancer NN 639 641 in in IN 642 648 Jurkat Jurkat NNP 649 650 T t NN 651 656 cells cell NNS 656 657 , , , 658 661 and and CC 662 666 that that IN 667 677 LEF-1/GAL4 lef-1/gal4 NN 678 681 can can MD 682 690 activate activate VB 691 692 a a DT 693 709 GAL4-substituted gal4-substituted JJ 710 715 HIV-1 HIV-1 NNP 716 724 enhancer enhancer NN 725 728 80- 80- CD 729 731 to to TO 732 740 100-fold 100-fold JJ 741 743 in in FW 744 748 vivo vivo FW 748 749 . . . 750 756 Second second JJ 756 757 , , , 758 769 recombinant recombinant JJ 770 775 LEF-1 lef-1 NN 776 778 is be VBZ 779 784 shown show VBN 785 787 to to TO 788 796 activate activate VB 797 802 HIV-1 HIV-1 NNP 803 816 transcription transcription NN 817 819 on on IN 820 839 chromatin-assembled chromatin-assembled JJ 840 843 DNA dna NN 844 846 in in FW 847 852 vitro vitro FW 852 853 . . . 854 856 By by IN 857 862 using use VBG 863 864 a a DT 865 884 nucleosome-assembly nucleosome-assembly NN 885 891 system system NN 892 899 derived derive VBN 900 904 from from IN 905 915 Drosophila drosophila FW 916 923 embryos embryo NNS 923 924 , , , 925 927 we we PRP 928 932 find find VBP 933 937 that that IN 938 941 the the DT 942 951 packaging packaging NN 952 954 of of IN 955 958 DNA dna NN 959 963 into into IN 964 973 chromatin chromatin NN 974 976 in in FW 977 982 vitro vitro FW 983 991 strongly strongly RB 992 1001 represses repress VBZ 1002 1007 HIV-1 HIV-1 NNP 1008 1021 transcription transcription NN 1022 1025 and and CC 1026 1030 that that IN 1031 1041 repression repression NN 1042 1045 can can MD 1046 1048 be be VB 1049 1061 counteracted counteract VBN 1062 1073 efficiently efficiently RB 1074 1076 by by IN 1077 1090 preincubation preincubation NN 1091 1093 of of IN 1094 1097 the the DT 1098 1101 DNA dna NN 1102 1106 with with IN 1107 1112 LEF-1 lef-1 NN 1113 1114 ( ( ( 1114 1116 or or CC 1117 1122 LEF-1 lef-1 NN 1123 1126 and and CC 1127 1132 Ets-1 ets-1 NN 1132 1133 ) ) ) 1134 1146 supplemented supplement VBN 1147 1151 with with IN 1152 1161 fractions fraction NNS 1162 1172 containing contain VBG 1173 1176 the the DT 1177 1193 promoter-binding promoter-binding JJ 1194 1201 protein protein NN 1201 1202 , , , 1203 1206 Sp1 Sp1 NNP 1206 1207 . . . 1208 1216 Addition addition NN 1217 1219 of of IN 1220 1225 TFE-3 TFE-3 NNP 1225 1226 , , , 1227 1232 which which WDT 1233 1238 binds bind VBZ 1239 1241 to to TO 1242 1244 an an DT 1245 1250 E-box e-box NN 1251 1256 motif motif NN 1257 1265 upstream upstream JJ 1266 1268 of of IN 1269 1272 the the DT 1273 1278 LEF-1 lef-1 NN 1279 1282 and and CC 1283 1288 Ets-1 ets-1 NN 1289 1294 sites site NNS 1294 1295 , , , 1296 1303 further further RB 1304 1312 augments augment VBZ 1313 1326 transcription transcription NN 1327 1329 in in IN 1330 1334 this this DT 1335 1341 system system NN 1341 1342 . . . 1343 1355 Individually individually RB 1356 1358 or or CC 1359 1371 collectively collectively RB 1371 1372 , , , 1373 1377 none none NN 1378 1380 of of IN 1381 1384 the the DT 1385 1390 three three CD 1391 1407 enhancer-binding enhancer-binding JJ 1408 1416 proteins protein NNS 1417 1418 ( ( ( 1418 1423 LEF-1 LEF-1 NNP 1423 1424 , , , 1425 1430 Ets-1 Ets-1 NNP 1430 1431 , , , 1432 1435 and and CC 1436 1441 TFE-3 TFE-3 NNP 1441 1442 ) ) ) 1443 1448 could could MD 1449 1457 activate activate VB 1458 1471 transcription transcription NN 1472 1474 in in IN 1475 1478 the the DT 1479 1486 absence absence NN 1487 1489 of of IN 1490 1493 Sp1 Sp1 NNP 1493 1494 . . . 1495 1496 A a DT 1497 1507 truncation truncation NN 1508 1514 mutant mutant NN 1515 1517 of of IN 1518 1523 LEF-1 LEF-1 NNP 1524 1525 ( ( ( 1525 1531 HMG-88 HMG-88 NNP 1531 1532 ) ) ) 1532 1533 , , , 1534 1539 which which WDT 1540 1548 contains contain VBZ 1549 1552 the the DT 1553 1556 HMG HMG NNP 1557 1560 box box NN 1561 1564 but but CC 1565 1570 lacks lack VBZ 1571 1574 the the DT 1575 1591 trans-activation trans-activation NN 1592 1598 domain domain NN 1598 1599 , , , 1600 1603 did do VBD 1604 1607 not not RB 1608 1616 activate activate VB 1617 1630 transcription transcription NN 1631 1635 from from IN 1636 1647 nucleosomal nucleosomal JJ 1648 1651 DNA dna NN 1651 1652 , , , 1653 1663 indicating indicate VBG 1664 1668 that that IN 1669 1676 bending bend VBG 1677 1679 of of IN 1680 1683 DNA dna NN 1684 1686 by by IN 1687 1690 the the DT 1691 1694 HMG HMG NNP 1695 1701 domain domain NN 1702 1704 is be VBZ 1705 1708 not not RB 1709 1719 sufficient sufficient JJ 1720 1722 to to TO 1723 1731 activate activate VB 1732 1745 transcription transcription NN 1746 1748 in in FW 1749 1754 vitro vitro FW 1754 1755 . . . 1756 1758 We we PRP 1759 1767 conclude conclude VBP 1768 1772 that that IN 1773 1786 transcription transcription NN 1787 1797 activation activation NN 1798 1800 by by IN 1801 1806 LEF-1 lef-1 NN 1807 1809 in in FW 1810 1815 vitro vitro FW 1816 1818 is be VBZ 1819 1820 a a DT 1821 1840 chromatin-dependent chromatin-dependent JJ 1841 1848 process process NN 1849 1853 that that WDT 1854 1862 requires require VBZ 1863 1864 a a DT 1865 1875 functional functional JJ 1876 1892 trans-activation trans-activation NN 1893 1899 domain domain NN 1900 1902 in in IN 1903 1911 addition addition NN 1912 1914 to to TO 1915 1918 the the DT 1919 1922 HMG HMG NNP 1923 1929 domain domain NN 1929 1930 . . .