0 9 Inducible inducible JJ 10 20 expression expression NN 21 24 and and CC 25 40 phosphorylation phosphorylation NN 41 43 of of IN 44 55 coactivator coactivator NN 56 67 BOB.1/OBF.1 bob.1/obf.1 NN 68 70 in in IN 71 72 T t NN 73 78 cells cell NNS 79 80 [ [ ( 80 83 see see VB 84 92 comments comment NNS 92 93 ] ] ) 95 106 BOB.1/OBF.1 BOB.1/OBF.1 NNP 107 109 is be VBZ 110 111 a a DT 112 127 transcriptional transcriptional JJ 128 139 coactivator coactivator NN 140 144 that that WDT 145 147 is be VBZ 148 162 constitutively constitutively RB 163 172 expressed express VBN 173 175 in in IN 176 177 B B NNP 178 183 cells cell NNS 184 187 and and CC 188 197 interacts interact VBZ 198 202 with with IN 203 206 the the DT 207 211 Oct1 oct1 NN 212 215 and and CC 216 220 Oct2 oct2 NN 221 234 transcription transcription NN 235 242 factors factor NNS 242 243 . . . 244 248 Upon upon IN 249 259 activation activation NN 260 262 of of IN 263 269 Jurkat Jurkat NNP 270 271 T t NN 272 277 cells cell NNS 278 281 and and CC 282 289 primary primary JJ 290 296 murine murine JJ 297 307 thymocytes thymocyte NNS 308 312 with with IN 313 320 phorbol phorbol NN 321 327 esters ester NNS 328 331 and and CC 332 341 ionomycin ionomycin NN 341 342 , , , 343 354 BOB.1/OBF.1 bob.1/obf.1 NN 355 365 expression expression NN 366 369 and and CC 370 385 transactivation transactivation NN 386 394 function function NN 395 399 were be VBD 400 407 induced induce VBN 407 408 . . . 409 420 BOB.1/OBF.1 BOB.1/OBF.1 NNP 421 424 was be VBD 425 439 phosphorylated phosphorylate VBN 440 442 at at IN 443 449 Ser184 ser184 NN 450 454 both both CC 455 457 in in FW 458 462 vivo vivo FW 463 466 and and CC 467 469 in in FW 470 475 vitro vitro FW 475 476 , , , 477 480 and and CC 481 485 this this DT 486 498 modification modification NN 499 502 was be VBD 503 511 required require VBN 512 515 for for IN 516 525 inducible inducible JJ 526 536 activation activation NN 536 537 . . . 538 546 Mutation mutation NN 547 549 of of IN 550 556 Ser184 ser184 NN 557 561 also also RB 562 572 diminished diminish VBD 573 588 transactivation transactivation NN 589 597 function function NN 598 600 in in IN 601 602 B B NNP 603 608 cells cell NNS 608 609 , , , 610 620 suggesting suggest VBG 621 625 that that IN 626 629 the the DT 630 640 activating activate VBG 641 656 phosphorylation phosphorylation NN 657 661 that that WDT 662 664 is be VBZ 665 674 inducible inducible JJ 675 677 in in IN 678 679 T t NN 680 685 cells cell NNS 686 688 is be VBZ 689 703 constitutively constitutively RB 704 711 present present JJ 712 714 in in IN 715 716 B B NNP 717 722 cells cell NNS 722 723 . . . 724 728 Thus thus RB 728 729 , , , 730 741 BOB.1/OBF.1 BOB.1/OBF.1 NNP 742 744 is be VBZ 745 746 a a DT 747 762 transcriptional transcriptional JJ 763 774 coactivator coactivator NN 775 779 that that WDT 780 782 is be VBZ 783 793 critically critically RB 794 803 regulated regulate VBN 804 806 by by IN 807 824 posttranslational posttranslational JJ 825 838 modifications modification NNS 839 841 to to TO 842 849 mediate mediate VB 850 854 cell cell NN 855 868 type-specific type-specific JJ 869 873 gene gene NN 874 884 expression expression NN 884 885 . . .