0 10 Downstream downstream JJ 11 21 activation activation NN 22 24 of of IN 25 26 a a DT 27 36 TATA-less tata-less JJ 37 45 promoter promoter NN 46 48 by by IN 49 54 Oct-2 oct-2 NN 54 55 , , , 56 60 Bob1 Bob1 NNP 60 61 , , , 62 65 and and CC 66 75 NF-kappaB NF-kappaB NNP 76 83 directs direct VBZ 84 94 expression expression NN 95 97 of of IN 98 101 the the DT 102 108 homing homing JJ 109 117 receptor receptor NN 118 122 BLR1 blr1 NN 123 125 to to TO 126 132 mature mature JJ 133 134 B B NNP 135 140 cells cell NNS 140 141 . . . 143 146 The the DT 147 156 chemokine chemokine NN 157 165 receptor receptor NN 165 166 , , , 167 171 BLR1 BLR1 NNP 171 172 , , , 173 175 is be VBZ 176 177 a a DT 178 183 major major JJ 184 193 regulator regulator NN 194 196 of of IN 197 200 the the DT 201 219 microenvironmental microenvironmental JJ 220 226 homing homing NN 227 229 of of IN 230 231 B B NNP 232 237 cells cell NNS 238 240 in in IN 241 249 lymphoid lymphoid JJ 250 256 organs organ NNS 256 257 . . . 258 260 In in FW 261 266 vitro vitro FW 267 274 studies study NNS 275 283 identify identify VBP 284 289 three three CD 290 299 essential essential JJ 300 308 elements element NNS 309 311 of of IN 312 315 the the DT 316 325 TATA-less tata-less JJ 326 330 blr1 blr1 NN 331 335 core core NN 336 344 promoter promoter NN 345 349 that that WDT 350 356 confer confer VBP 357 361 cell cell NN 362 367 type- type- NN 368 371 and and CC 372 396 differentiation-specific differentiation-specific JJ 397 407 expression expression NN 408 410 in in IN 411 414 the the DT 415 416 B B NNP 417 422 cells cell NNS 423 425 of of IN 426 430 both both CC 431 437 humans human NNS 438 441 and and CC 442 446 mice mouse NNS 446 447 , , , 448 449 a a DT 450 460 functional functional JJ 461 469 promoter promoter NN 470 476 region region NN 477 478 ( ( ( 478 481 -36 -36 CD 482 486 with with IN 487 494 respect respect NN 495 497 to to TO 498 501 the the DT 502 515 transcription transcription NN 516 521 start start NN 522 526 site site NN 526 527 ) ) ) 527 528 , , , 529 530 a a DT 531 540 NF-kappaB NF-kappaB NNP 541 546 motif motif NN 547 548 ( ( ( 548 551 +44 +44 CD 551 552 ) ) ) 552 553 , , , 554 557 and and CC 558 559 a a DT 560 572 noncanonical noncanonical JJ 573 580 octamer octamer NN 581 586 motif motif NN 587 588 ( ( ( 588 592 +157 +157 CD 592 593 ) ) ) 593 594 . . . 595 598 The the DT 599 609 importance importance NN 610 612 of of IN 613 618 these these DT 619 624 sites site NNS 625 628 was be VBD 629 638 confirmed confirm VBN 639 641 by by IN 642 644 in in FW 645 649 vivo vivo FW 650 657 studies study NNS 658 660 in in IN 661 674 gene-targeted gene-targeted JJ 675 679 mice mouse NNS 680 689 deficient deficient JJ 690 692 of of IN 693 699 either either CC 700 705 Oct-2 oct-2 NN 705 706 , , , 707 711 Bob1 Bob1 NNP 711 712 , , , 713 715 or or CC 716 720 both both CC 721 730 NF-kappaB NF-kappaB NNP 731 739 subunits subunit NNS 740 743 p50 p50 NN 744 747 and and CC 748 751 p52 p52 NN 751 752 . . . 753 755 In in IN 756 759 all all DT 760 762 of of IN 763 768 these these DT 769 776 animals animal NNS 776 777 , , , 778 781 the the DT 782 792 expression expression NN 793 795 of of IN 796 800 BLR1 BLR1 NNP 801 804 was be VBD 805 812 reduced reduce VBN 813 815 or or CC 816 822 absent absent JJ 822 823 . . . 824 826 In in IN 827 831 mice mouse NNS 832 841 deficient deficient JJ 842 846 only only RB 847 849 of of IN 850 863 p52/NF-kappaB p52/NF-kappaB NNP 863 864 , , , 865 869 BLR1 blr1 NN 870 880 expression expression NN 881 884 was be VBD 885 895 unaffected unaffected JJ 895 896 . . . 897 901 Thus thus RB 902 905 our our PRP$ 906 910 data datum NNS 911 922 demonstrate demonstrate VBP 923 927 that that IN 928 932 BLR1 blr1 NN 933 935 is be VBZ 936 937 a a DT 938 944 target target NN 945 949 gene gene NN 950 953 for for IN 954 959 Oct-2 oct-2 NN 959 960 , , , 961 965 Bob1 Bob1 NNP 965 966 , , , 967 970 and and CC 971 978 members member NNS 979 981 of of IN 982 985 the the DT 986 999 NF-kappaB/Rel NF-kappaB/Rel NNP 1000 1006 family family NN 1007 1010 and and CC 1011 1019 provides provide VBZ 1020 1021 a a DT 1022 1026 link link NN 1027 1029 to to TO 1030 1033 the the DT 1034 1042 impaired impaired JJ 1043 1044 B B NNP 1045 1049 cell cell NN 1050 1059 functions function NNS 1060 1062 in in IN 1063 1067 mice mouse NNS 1068 1077 deficient deficient JJ 1078 1081 for for IN 1082 1087 these these DT 1088 1095 factors factor NNS 1095 1096 . . .