0 13 Transcription transcription NN 14 16 of of IN 17 20 the the DT 21 35 hypersensitive hypersensitive JJ 36 40 site site NN 41 44 HS2 hs2 NN 45 53 enhancer enhancer NN 54 56 in in IN 57 66 erythroid erythroid JJ 67 72 cells cell NNS 72 73 . . . 75 77 In in IN 78 81 the the DT 82 87 human human JJ 88 94 genome genome NN 94 95 , , , 96 99 the the DT 100 118 erythroid-specific erythroid-specific JJ 119 133 hypersensitive hypersensitive JJ 134 138 site site NN 139 142 HS2 hs2 NN 143 151 enhancer enhancer NN 152 161 regulates regulate VBZ 162 165 the the DT 166 179 transcription transcription NN 180 182 of of IN 183 186 the the DT 187 197 downstream downstream JJ 198 207 beta-like beta-like JJ 208 214 globin globin NN 215 220 genes gene NNS 221 226 10-50 10-50 CD 227 236 kilobases kilobas NNS 237 241 away away RB 241 242 . . . 243 246 The the DT 247 256 mechanism mechanism NN 257 259 of of IN 260 263 HS2 hs2 NN 264 272 enhancer enhancer NN 273 281 function function NN 282 284 is be VBZ 285 288 not not RB 289 294 known know VBN 294 295 . . . 296 299 The the DT 300 307 present present JJ 308 313 study study NN 314 321 employs employ VBZ 322 325 RNA RNA NNP 326 336 protection protection NN 337 343 assays assay NNS 344 346 to to TO 347 354 analyze analyze VB 355 358 the the DT 359 374 transcriptional transcriptional JJ 375 381 status status NN 382 384 of of IN 385 388 the the DT 389 392 HS2 hs2 NN 393 401 enhancer enhancer NN 402 404 in in IN 405 416 transfected transfecte VBN 417 428 recombinant recombinant JJ 429 444 chloramphenicol chloramphenicol NN 445 462 acetyltransferase acetyltransferase NN 463 464 ( ( ( 464 467 CAT CAT NNP 467 468 ) ) ) 469 477 plasmids plasmid NNS 477 478 . . . 479 481 In in IN 482 491 erythroid erythroid JJ 492 496 K562 k562 NN 497 502 cells cell NNS 503 505 in in IN 506 511 which which WDT 512 515 the the DT 516 519 HS2 hs2 NN 520 528 enhancer enhancer NN 529 531 is be VBZ 532 538 active active JJ 538 539 , , , 540 543 the the DT 544 547 HS2 hs2 NN 548 556 sequence sequence NN 557 564 directs direct VBZ 565 568 the the DT 569 578 synthesis synthesis NN 579 581 of of IN 582 586 long long JJ 587 595 enhancer enhancer NN 596 607 transcripts transcript NNS 608 612 that that WDT 613 616 are be VBP 617 626 initiated initiate VBN 627 637 apparently apparently RB 638 642 from from IN 643 649 within within IN 650 653 the the DT 654 662 enhancer enhancer NN 663 666 and and CC 667 676 elongated elongate VBD 677 684 through through IN 685 688 the the DT 689 700 intervening intervene VBG 701 704 DNA dna NN 705 709 into into IN 710 713 the the DT 714 724 cis-linked cis-linked JJ 725 728 CAT CAT NNP 729 733 gene gene NN 733 734 . . . 735 737 In in IN 738 750 nonerythroid nonerythroid JJ 751 756 HL-60 hl-60 NN 757 762 cells cell NNS 763 765 in in IN 766 771 which which WDT 772 775 the the DT 776 779 HS2 hs2 NN 780 788 enhancer enhancer NN 789 791 is be VBZ 792 800 inactive inactive JJ 800 801 , , , 802 806 long long JJ 807 815 enhancer enhancer NN 816 827 transcripts transcript NNS 828 831 are be VBP 832 835 not not RB 836 846 detectable detectable JJ 846 847 . . . 848 857 Splitting split VBG 858 861 the the DT 862 865 HS2 hs2 NN 866 874 enhancer enhancer NN 875 882 between between IN 883 886 two two CD 887 893 tandem tandem JJ 894 897 Ap1 ap1 NN 898 903 sites site NNS 904 913 abolishes abolish VBZ 914 917 the the DT 918 927 synthesis synthesis NN 928 930 of of IN 931 932 a a DT 933 938 group group NN 939 941 of of IN 942 946 long long JJ 947 955 enhancer enhancer NN 956 967 transcripts transcript NNS 968 971 and and CC 972 979 results result VBZ 980 982 in in IN 983 987 loss loss NN 988 990 of of IN 991 999 enhancer enhancer NN 1000 1008 function function NN 1009 1012 and and CC 1013 1028 transcriptional transcriptional JJ 1029 1038 silencing silencing NN 1039 1041 of of IN 1042 1045 the the DT 1046 1056 cis-linked cis-linked JJ 1057 1060 CAT CAT NNP 1061 1065 gene gene NN 1065 1066 . . . 1067 1069 In in IN 1070 1079 directing direct VBG 1080 1083 the the DT 1084 1093 synthesis synthesis NN 1094 1096 of of IN 1097 1100 RNA RNA NNP 1101 1108 through through IN 1109 1112 the the DT 1113 1124 intervening intervene VBG 1125 1128 DNA dna NN 1129 1132 and and CC 1133 1136 the the DT 1137 1141 gene gene NN 1142 1144 by by IN 1145 1146 a a DT 1147 1155 tracking tracking NN 1156 1159 and and CC 1160 1173 transcription transcription NN 1174 1183 mechanism mechanism NN 1183 1184 , , , 1185 1188 the the DT 1189 1192 HS2 hs2 NN 1193 1201 enhancer enhancer NN 1202 1205 may may MD 1206 1207 ( ( ( 1207 1208 i i LS 1208 1209 ) ) ) 1210 1214 open open VB 1215 1217 up up RP 1218 1221 the the DT 1222 1231 chromatin chromatin NN 1232 1241 structure structure NN 1242 1244 of of IN 1245 1246 a a DT 1247 1251 gene gene NN 1252 1258 domain domain NN 1259 1262 and and CC 1263 1264 ( ( ( 1264 1266 ii ii LS 1266 1267 ) ) ) 1268 1275 deliver deliver VB 1276 1284 enhancer enhancer NN 1285 1292 binding binding NN 1293 1301 proteins protein NNS 1302 1304 to to TO 1305 1308 the the DT 1309 1317 promoter promoter NN 1318 1326 sequence sequence NN 1327 1332 where where WRB 1333 1337 they they PRP 1338 1341 may may MD 1342 1351 stimulate stimulate VB 1352 1355 the the DT 1356 1369 transcription transcription NN 1370 1372 of of IN 1373 1376 the the DT 1377 1381 gene gene NN 1382 1384 at at IN 1385 1388 the the DT 1389 1392 cap cap NN 1393 1397 site site NN 1397 1398 . . .