0 1 A a DT 2 7 novel novel JJ 8 15 genetic genetic JJ 16 22 system system NN 23 25 to to TO 26 33 isolate isolate VB 34 35 a a DT 36 44 dominant dominant JJ 45 53 negative negative JJ 54 62 effector effector NN 63 65 on on IN 66 77 DNA-binding dna-binding JJ 78 86 activity activity NN 87 89 of of IN 90 95 Oct-2 oct-2 NN 95 96 . . . 98 104 Recent recent JJ 105 112 studies study NNS 113 117 have have VBP 118 126 revealed reveal VBN 127 131 that that IN 132 144 interactions interaction NNS 145 152 between between IN 153 166 transcription transcription NN 167 174 factors factor NNS 175 179 play play VBP 180 182 an an DT 183 192 important important JJ 193 197 role role NN 198 200 in in IN 201 211 regulation regulation NN 212 214 of of IN 215 219 gene gene NN 220 230 expression expression NN 231 233 in in IN 234 244 eukaryotic eukaryotic JJ 245 250 cells cell NNS 250 251 . . . 252 254 To to TO 255 262 isolate isolate VB 263 267 cDNA cdna NN 268 274 clones clone NNS 275 279 that that WDT 280 290 dominantly dominantly RB 291 298 inhibit inhibit VBP 299 302 the the DT 303 314 DNA-binding dna-binding JJ 315 323 activity activity NN 324 326 of of IN 327 332 Oct-2 oct-2 NN 332 333 , , , 334 340 chosen choose VBN 341 343 as as IN 344 345 a a DT 346 360 representative representative JJ 361 367 factor factor NN 367 368 , , , 369 371 we we PRP 372 376 have have VBP 377 386 developed develop VBN 387 388 a a DT 389 394 novel novel JJ 395 404 screening screening NN 405 411 system system NN 411 412 . . . 413 417 This this DT 418 425 employs employ VBZ 426 428 an an DT 429 440 Escherichia escherichia FW 441 445 coli coli FW 446 452 tester tester NN 453 459 strain strain NN 460 468 carrying carry VBG 469 470 a a DT 471 479 modified modify VBN 480 483 lac lac NN 484 490 operon operon NN 491 493 as as IN 494 495 a a DT 496 504 reporter reporter NN 505 509 gene gene NN 509 510 , , , 511 515 with with IN 516 519 the the DT 520 523 lac lac NN 524 532 operator operator NN 533 541 sequence sequence NN 542 550 replaced replace VBN 551 553 by by IN 554 556 an an DT 557 564 octamer octamer NN 565 573 sequence sequence NN 573 574 . . . 575 580 Oct-2 oct-2 NN 581 590 expressed express VBN 591 593 in in IN 594 598 this this DT 599 605 tester tester NN 606 612 strain strain NN 613 622 represses repress VBZ 623 626 the the DT 627 637 expression expression NN 638 640 of of IN 641 644 the the DT 645 653 reporter reporter NN 654 658 gene gene NN 659 662 and and CC 663 670 changes change VBZ 671 674 the the DT 675 684 phenotype phenotype NN 685 687 of of IN 688 691 the the DT 692 696 cell cell NN 697 701 from from IN 702 708 Lac+to Lac+to NNP 709 713 Lac- Lac- NNP 713 714 . . . 715 727 Introduction introduction NN 728 730 of of IN 731 732 a a DT 733 737 cDNA cdna NN 738 748 expression expression NN 749 756 library library NN 757 765 prepared prepare VBN 766 770 from from IN 771 772 a a DT 773 778 human human JJ 779 785 T-cell t-cell NN 786 790 line line NN 791 795 into into IN 796 799 the the DT 800 815 Oct-2-harboring oct-2-harboring JJ 816 822 tester tester NN 823 829 strain strain NN 830 837 allowed allow VBD 838 847 selection selection NN 848 850 of of IN 851 856 three three CD 857 867 Lac+clones lac+clone NNS 868 871 out out IN 872 874 of of IN 875 876 1 1 CD 877 878 x x SYM 879 884 10(5) 10(5) CD 885 898 transformants transformant NNS 898 899 . . . 900 903 One one CD 904 906 of of IN 907 911 them them PRP 911 912 , , , 913 917 hT86 ht86 NN 917 918 , , , 919 927 encoding encode VBG 928 929 a a DT 930 938 putative putative JJ 939 943 zinc zinc NN 944 950 finger finger NN 951 958 protein protein NN 959 962 was be VBD 963 968 found find VBN 969 971 to to TO 972 981 derepress derepress VB 982 1000 beta-galactosidase beta-galactosidase NN 1001 1009 activity activity NN 1010 1012 in in IN 1013 1016 the the DT 1017 1032 Oct-2-harboring oct-2-harboring JJ 1033 1039 tester tester NN 1040 1046 strain strain NN 1047 1049 at at IN 1050 1053 the the DT 1054 1069 transcriptional transcriptional JJ 1070 1075 level level NN 1075 1076 . . . 1077 1079 In in IN 1080 1083 gel gel NN 1084 1092 mobility mobility NN 1093 1098 shift shift NN 1099 1105 assays assay NNS 1105 1106 , , , 1107 1111 hT86 ht86 NN 1112 1122 attenuated attenuate VBD 1123 1126 the the DT 1127 1136 intensity intensity NN 1137 1139 of of IN 1140 1143 the the DT 1144 1152 retarded retard VBN 1153 1157 band band NN 1158 1166 composed compose VBN 1167 1169 of of IN 1170 1173 the the DT 1174 1181 octamer octamer NN 1182 1187 probe probe NN 1188 1191 and and CC 1192 1197 Oct-2 oct-2 NN 1197 1198 , , , 1199 1209 suggesting suggest VBG 1210 1211 a a DT 1212 1220 dominant dominant JJ 1221 1229 negative negative JJ 1230 1236 effect effect NN 1237 1239 on on IN 1240 1243 the the DT 1244 1255 DNA-binding dna-binding JJ 1256 1264 activity activity NN 1265 1267 of of IN 1268 1273 Oct-2 oct-2 NN 1273 1274 . . . 1275 1278 The the DT 1279 1287 strategy strategy NN 1288 1297 described describe VBN 1298 1302 here here RB 1303 1311 provides provide VBZ 1312 1313 a a DT 1314 1317 new new JJ 1318 1326 approach approach NN 1327 1330 for for IN 1331 1339 studying study VBG 1340 1355 protein-protein protein-protein JJ 1356 1368 interactions interaction NNS 1369 1373 that that WDT 1374 1380 govern govern VBP 1381 1384 the the DT 1385 1392 complex complex JJ 1393 1403 regulation regulation NN 1404 1406 of of IN 1407 1411 gene gene NN 1412 1422 expression expression NN 1422 1423 . . .