0 16 Characterization characterization NN 17 19 of of IN 20 21 a a DT 22 30 cofactor cofactor NN 31 35 that that WDT 36 45 regulates regulate VBZ 46 58 dimerization dimerization NN 59 61 of of IN 62 63 a a DT 64 73 mammalian mammalian JJ 74 85 homeodomain homeodomain NN 86 93 protein protein NN 93 94 . . . 96 108 Dimerization dimerization NN 109 114 among among IN 115 128 transcription transcription NN 129 136 factors factor NNS 137 140 has have VBZ 141 147 become become VBN 148 149 a a DT 150 159 recurrent recurrent JJ 160 165 theme theme NN 166 168 in in IN 169 172 the the DT 173 183 regulation regulation NN 184 186 of of IN 187 197 eukaryotic eukaryotic JJ 198 202 gene gene NN 203 213 expression expression NN 213 214 . . . 215 225 Hepatocyte Hepatocyte NNP 226 233 nuclear nuclear JJ 234 242 factor-1 factor-1 NN 243 248 alpha alpha NN 249 250 ( ( ( 250 255 HNF-1 hnf-1 NN 256 261 alpha alpha NN 261 262 ) ) ) 263 265 is be VBZ 266 267 a a DT 268 290 homeodomain-containing homeodomain-containing JJ 291 298 protein protein NN 299 303 that that WDT 304 313 functions function VBZ 314 316 as as IN 317 318 a a DT 319 324 dimer dimer NN 324 325 . . . 326 327 A a DT 328 340 dimerization dimerization NN 341 349 cofactor cofactor NN 350 352 of of IN 353 358 HNF-1 hnf-1 NN 359 364 alpha alpha NN 365 366 ( ( ( 366 370 DCoH DCoH NNP 370 371 ) ) ) 372 375 was be VBD 376 386 identified identify VBN 387 391 that that WDT 392 401 displayed display VBD 402 403 a a DT 404 414 restricted restricted JJ 415 421 tissue tissue NN 422 434 distribution distribution NN 435 438 and and CC 439 442 did do VBD 443 446 not not RB 447 451 bind bind VB 452 454 to to TO 455 458 DNA DNA NNP 458 459 , , , 460 463 but but CC 463 464 , , , 465 471 rather rather RB 471 472 , , , 473 484 selectively selectively RB 485 495 stabilized stabilize VBD 496 501 HNF-1 hnf-1 NN 502 507 alpha alpha NN 508 514 dimers dimer NNS 514 515 . . . 516 519 The the DT 520 529 formation formation NN 530 532 of of IN 533 534 a a DT 535 541 stable stable JJ 542 552 tetrameric tetrameric JJ 553 563 DCoH-HNF-1 dcoh-hnf-1 NN 564 569 alpha alpha NN 570 577 complex complex NN 577 578 , , , 579 584 which which WDT 585 593 required require VBD 594 597 the the DT 598 610 dimerization dimerization NN 611 617 domain domain NN 618 620 of of IN 621 626 HNF-1 hnf-1 NN 627 632 alpha alpha NN 632 633 , , , 634 637 did do VBD 638 641 not not RB 642 648 change change VB 649 652 the the DT 653 656 DNA dna NN 657 664 binding binding NN 665 680 characteristics characteristic NNS 681 683 of of IN 684 689 HNF-1 hnf-1 NN 690 695 alpha alpha NN 695 696 , , , 697 700 but but CC 701 709 enhanced enhance VBD 710 713 its its PRP$ 714 729 transcriptional transcriptional JJ 730 738 activity activity NN 738 739 . . . 740 747 However however RB 747 748 , , , 749 753 DCoH DCoH NNP 754 757 did do VBD 758 761 not not RB 762 768 confer confer VB 769 784 transcriptional transcriptional JJ 785 795 activation activation NN 796 798 to to TO 799 802 the the DT 803 807 GAL4 GAL4 NNP 808 811 DNA DNA NNP 812 819 binding binding NN 820 826 domain domain NN 826 827 . . . 828 833 These these DT 834 841 results result NNS 842 850 indicate indicate VBP 851 855 that that IN 856 860 DCoH DCoH NNP 861 870 regulates regulate VBZ 871 880 formation formation NN 881 883 of of IN 884 901 transcriptionally transcriptionally RB 902 908 active active JJ 909 919 tetrameric tetrameric JJ 920 929 complexes complex NNS 930 933 and and CC 934 937 may may MD 938 948 contribute contribute VB 949 951 to to TO 952 955 the the DT 956 969 developmental developmental JJ 970 981 specificity specificity NN 982 984 of of IN 985 988 the the DT 989 996 complex complex NN 996 997 . . .