0 8 Targeted target VBN 9 20 degradation degradation NN 21 23 of of IN 24 29 c-Fos c-fos NN 29 30 , , , 31 34 but but CC 35 38 not not RB 39 44 v-Fos v-fos NN 44 45 , , , 46 48 by by IN 49 50 a a DT 51 76 phosphorylation-dependent phosphorylation-dependent JJ 77 83 signal signal NN 84 86 on on IN 87 92 c-Jun c-jun NN 92 93 . . . 95 98 The the DT 99 113 proto-oncogene proto-oncogene NN 114 122 products product NNS 123 128 c-Fos c-fos NN 129 132 and and CC 133 138 c-Jun c-jun NN 139 153 heterodimerize heterodimerize VBP 154 161 through through IN 162 167 their their PRP$ 168 175 leucine leucine NN 176 183 zippers zipper NNS 184 186 to to TO 187 191 form form VB 192 195 the the DT 196 200 AP-1 ap-1 NN 201 214 transcription transcription NN 215 221 factor factor NN 221 222 . . . 223 226 The the DT 227 242 transcriptional transcriptional JJ 243 251 activity activity NN 252 254 of of IN 255 258 the the DT 259 270 heterodimer heterodimer NN 271 273 is be VBZ 274 283 regulated regulate VBN 284 286 by by IN 287 303 signal-dependent signal-dependent JJ 304 319 phosphorylation phosphorylation NN 320 323 and and CC 324 341 dephosphorylation dephosphorylation NN 342 348 events event NNS 348 349 . . . 350 353 The the DT 354 363 stability stability NN 364 366 of of IN 367 372 c-Fos c-fos NN 373 376 was be VBD 377 382 found find VBN 383 385 to to TO 386 390 also also RB 391 393 be be VB 394 404 controlled control VBN 405 407 by by IN 408 421 intracellular intracellular JJ 422 428 signal signal NN 429 441 transduction transduction NN 441 442 . . . 443 445 In in IN 446 455 transient transient JJ 456 466 expression expression NN 467 470 and and CC 471 473 in in FW 474 479 vitro vitro FW 480 491 degradation degradation NN 492 503 experiments experiment NNS 503 504 , , , 505 508 the the DT 509 518 stability stability NN 519 521 of of IN 522 527 c-Fos c-fos NN 528 531 was be VBD 532 541 decreased decrease VBN 542 546 when when WRB 547 550 the the DT 551 558 protein protein NN 559 562 was be VBD 563 572 dimerized dimerize VBN 573 577 with with IN 578 592 phosphorylated phosphorylate VBN 593 599 c-Jun. c-jun. NN 600 605 c-Jun c-jun NN 606 613 protein protein NN 614 622 isolated isolate VBN 623 627 from from IN 628 635 phorbol phorbol NN 636 649 ester-induced ester-induced JJ 650 655 cells cell NNS 656 659 did do VBD 660 663 not not RB 664 670 target target VB 671 676 c-Fos c-fos NN 677 680 for for IN 681 692 degradation degradation NN 692 693 , , , 694 699 which which WDT 700 708 suggests suggest VBZ 709 713 that that IN 714 719 c-Fos c-fos NN 720 722 is be VBZ 723 734 transiently transiently RB 735 745 stabilized stabilize VBN 746 751 after after IN 752 763 stimulation stimulation NN 764 766 of of IN 767 771 cell cell NN 772 779 growth. growth. NN 780 785 v-Fos v-fos NN 786 793 protein protein NN 793 794 , , , 795 798 the the DT 799 809 retroviral retroviral JJ 810 821 counterpart counterpart NN 822 824 of of IN 825 830 c-Fos c-fos NN 830 831 , , , 832 835 was be VBD 836 839 not not RB 840 851 susceptible susceptible JJ 852 854 to to TO 855 866 degradation degradation NN 867 875 targeted target VBN 876 878 by by IN 879 884 c-Jun c-jun NN 884 885 . . .