0 7 Octamer Octamer NNP 8 15 binding binding NN 16 23 factors factor NNS 24 27 and and CC 28 33 their their PRP$ 34 45 coactivator coactivator NN 46 49 can can MD 50 58 activate activate VB 59 62 the the DT 63 69 murine murine JJ 70 74 PU.1 pu.1 NN 75 76 ( ( ( 76 81 spi-1 spi-1 NN 81 82 ) ) ) 83 91 promoter promoter NN 91 92 . . . 94 98 PU.1 PU.1 NNP 99 100 ( ( ( 100 105 spi-1 spi-1 NN 105 106 ) ) ) 106 107 , , , 108 109 a a DT 110 116 member member NN 117 119 of of IN 120 123 the the DT 124 127 Ets Ets NNP 128 141 transcription transcription NN 142 148 factor factor NN 149 155 family family NN 155 156 , , , 157 159 is be VBZ 160 173 predominantly predominantly RB 174 183 expressed express VBN 184 186 in in IN 187 194 myeloid myeloid JJ 195 198 and and CC 199 200 B B NNP 201 206 cells cell NNS 206 207 , , , 208 217 activates activate VBZ 218 222 many many JJ 223 224 B B NNP 225 229 cell cell NN 230 233 and and CC 234 241 myeloid myeloid JJ 242 247 genes gene NNS 247 248 , , , 249 252 and and CC 253 255 is be VBZ 256 264 critical critical JJ 265 268 for for IN 269 280 development development NN 281 283 of of IN 284 288 both both DT 289 291 of of IN 292 297 these these DT 298 306 lineages lineage NNS 306 307 . . . 308 311 Our our PRP$ 312 320 previous previous JJ 321 328 studies study NNS 329 330 ( ( ( 330 334 Chen Chen NNP 334 335 , , , 336 340 H.M. H.M. NNP 340 341 , , , 342 352 Ray-Gallet Ray-Gallet NNP 352 353 , , , 354 356 D. D. NNP 356 357 , , , 358 363 Zhang Zhang NNP 363 364 , , , 365 367 P. P. NNP 367 368 , , , 369 381 Hetherington Hetherington NNP 381 382 , , , 383 387 C.J. C.J. NNP 387 388 , , , 389 397 Gonzalez Gonzalez NNP 397 398 , , , 399 403 D.A. D.A. NNP 403 404 , , , 405 410 Zhang Zhang NNP 410 411 , , , 412 417 D.-E. D.-E. NNP 417 418 , , , 419 434 Moreau-Gachelin Moreau-Gachelin NNP 434 435 , , , 436 438 F. F. NNP 438 439 , , , 440 443 and and CC 444 449 Tenen Tenen NNP 449 450 , , , 451 461 D.G.(1995) D.G.(1995) NNP 462 470 Oncogene Oncogene NNP 471 473 11 11 CD 473 474 , , , 475 484 1549-1560 1549-1560 CD 484 485 ) ) ) 486 497 demonstrate demonstrate VBP 498 502 that that IN 503 506 the the DT 507 511 PU.1 pu.1 NN 512 520 promoter promoter NN 521 528 directs direct VBZ 529 533 cell cell NN 534 547 type-specific type-specific JJ 548 556 reporter reporter NN 557 561 gene gene NN 562 572 expression expression NN 573 575 in in IN 576 583 myeloid myeloid JJ 584 588 cell cell NN 589 594 lines line NNS 594 595 , , , 596 599 and and CC 600 604 that that IN 605 609 PU.1 pu.1 NN 610 619 activates activate VBZ 620 623 its its PRP$ 624 627 own own JJ 628 636 promoter promoter NN 637 639 in in IN 640 642 an an DT 643 657 autoregulatory autoregulatory JJ 658 662 loop loop NN 662 663 . . . 664 668 Here here RB 669 671 we we PRP 672 676 show show VBP 677 681 that that IN 682 685 the the DT 686 692 murine murine JJ 693 697 PU.1 pu.1 NN 698 706 promoter promoter NN 707 709 is be VBZ 710 714 also also RB 715 727 specifically specifically RB 728 731 and and CC 732 738 highly highly RB 739 749 functional functional JJ 750 752 in in IN 753 754 B B NNP 755 759 cell cell NN 760 765 lines line NNS 766 768 as as RB 769 773 well well RB 773 774 . . . 775 780 Oct-1 Oct-1 NNP 781 784 and and CC 785 790 Oct-2 oct-2 NN 791 794 can can MD 795 799 bind bind VB 800 812 specifically specifically RB 813 815 to to TO 816 817 a a DT 818 822 site site NN 823 825 at at IN 826 830 base base NN 831 835 pair pair NN 836 839 -55 -55 CD 840 842 in in FW 843 848 vitro vitro FW 848 849 , , , 850 853 and and CC 854 858 this this DT 859 863 site site NN 864 866 is be VBZ 867 879 specifically specifically RB 880 889 protected protect VBN 890 892 in in IN 893 894 B B NNP 895 900 cells cell NNS 901 903 in in FW 904 908 vivo vivo FW 908 909 . . . 910 912 We we PRP 913 917 also also RB 918 929 demonstrate demonstrate VBP 930 934 that that IN 935 938 two two CD 939 944 other other JJ 945 950 sites site NNS 951 961 contribute contribute VBP 962 964 to to TO 965 973 promoter promoter NN 974 982 activity activity NN 983 985 in in IN 986 987 B B NNP 988 993 cells cell NNS 993 994 ; ; : 995 997 an an DT 998 1001 Sp1 sp1 NN 1002 1009 binding binding NN 1010 1014 site site NN 1015 1023 adjacent adjacent JJ 1024 1026 to to TO 1027 1030 the the DT 1031 1038 octamer octamer NN 1039 1043 site site NN 1043 1044 , , , 1045 1048 and and CC 1049 1052 the the DT 1053 1057 PU.1 pu.1 NN 1058 1072 autoregulatory autoregulatory JJ 1073 1077 site site NN 1077 1078 . . . 1079 1086 Finally finally RB 1086 1087 , , , 1088 1090 we we PRP 1091 1095 show show VBP 1096 1100 that that IN 1101 1104 the the DT 1105 1106 B B NNP 1107 1111 cell cell NN 1112 1123 coactivator coactivator NN 1124 1140 OBF-1/Bob1/OCA-B obf-1/bob1/oca-b NN 1141 1143 is be VBZ 1144 1148 only only RB 1149 1158 expressed express VBN 1159 1161 in in IN 1162 1163 B B NNP 1164 1169 cells cell NNS 1170 1173 and and CC 1174 1177 not not RB 1178 1180 in in IN 1181 1188 myeloid myeloid JJ 1189 1194 cells cell NNS 1194 1195 , , , 1196 1199 and and CC 1200 1204 that that IN 1205 1221 OBF-1/Bob1/OCA-B OBF-1/Bob1/OCA-B NNP 1222 1225 can can MD 1226 1239 transactivate transactivate VB 1240 1243 the the DT 1244 1248 PU.1 pu.1 NN 1249 1257 promoter promoter NN 1258 1260 in in IN 1261 1265 HeLa HeLa NNP 1266 1269 and and CC 1270 1277 myeloid myeloid JJ 1278 1283 cells cell NNS 1283 1284 . . . 1285 1289 This this DT 1290 1291 B B NNP 1292 1296 cell cell NN 1297 1307 restricted restricted JJ 1308 1319 coactivator coactivator NN 1320 1323 may may MD 1324 1326 be be VB 1327 1338 responsible responsible JJ 1339 1342 for for IN 1343 1346 the the DT 1347 1348 B B NNP 1349 1353 cell cell NN 1354 1362 specific specific JJ 1363 1373 expression expression NN 1374 1376 of of IN 1377 1381 PU.1 pu.1 NN 1382 1390 mediated mediate VBN 1391 1393 by by IN 1394 1397 the the DT 1398 1405 octamer octamer NN 1406 1410 site site NN 1410 1411 . . .