0 14 Overexpression Overexpression NNP 15 17 of of IN 18 27 HSF2-beta HSF2-beta NNP 28 36 inhibits inhibit VBZ 37 50 hemin-induced hemin-induced JJ 51 55 heat heat NN 56 61 shock shock NN 62 66 gene gene NN 67 77 expression expression NN 78 81 and and CC 82 91 erythroid erythroid JJ 92 107 differentiation differentiation NN 108 110 in in IN 111 115 K562 k562 NN 116 121 cells cell NNS 121 122 . . . 124 135 Acquisition Acquisition NNP 136 138 of of IN 139 143 heat heat NN 144 149 shock shock NN 150 156 factor factor NN 157 158 2 2 CD 159 160 ( ( ( 160 164 HSF2 hsf2 NN 164 165 ) ) ) 166 169 DNA DNA NNP 170 177 binding binding NN 178 186 activity activity NN 187 189 is be VBZ 190 201 accompanied accompany VBN 202 204 by by IN 205 212 induced induce VBN 213 226 transcription transcription NN 227 229 of of IN 230 234 heat heat NN 235 240 shock shock NN 241 246 genes gene NNS 247 249 in in IN 250 263 hemin-treated hemin-treated JJ 264 268 K562 k562 NN 269 274 cells cell NNS 275 285 undergoing undergo VBG 286 295 erythroid erythroid JJ 296 311 differentiation differentiation NN 311 312 . . . 313 321 Previous previous JJ 322 329 studies study NNS 330 338 revealed reveal VBD 339 343 that that IN 344 348 HSF2 hsf2 NN 349 357 consists consist VBZ 358 360 of of IN 361 364 two two CD 365 378 alternatively alternatively RB 379 386 spliced splice VBN 387 395 isoforms isoform NNS 395 396 , , , 397 407 HSF2-alpha HSF2-alpha NNP 408 411 and and CC 412 421 HSF2-beta HSF2-beta NNP 421 422 , , , 423 428 whose whose WP$ 429 437 relative relative JJ 438 447 abundance abundance NN 448 450 is be VBZ 451 466 developmentally developmentally RB 467 476 regulated regulate VBN 477 480 and and CC 481 487 varies vary VBZ 488 495 between between IN 496 505 different different JJ 506 513 tissues tissue NNS 513 514 . . . 515 517 To to TO 518 529 investigate investigate VB 530 537 whether whether IN 538 541 the the DT 542 547 molar molar JJ 548 553 ratio ratio NN 554 556 of of IN 557 567 HSF2-alpha HSF2-alpha NNP 568 571 and and CC 572 581 HSF2-beta HSF2-beta NNP 582 590 isoforms isoform NNS 591 593 is be VBZ 594 601 crucial crucial JJ 602 605 for for IN 606 609 the the DT 610 620 activation activation NN 621 623 of of IN 624 628 HSF2 hsf2 NN 629 632 and and CC 633 640 whether whether IN 641 644 the the DT 645 649 HSF2 hsf2 NN 650 658 isoforms isoform NNS 659 663 play play VBP 664 676 functionally functionally RB 677 685 distinct distinct JJ 686 691 roles role NNS 692 698 during during IN 699 702 the the DT 703 717 hemin-mediated hemin-mediated JJ 718 727 erythroid erythroid JJ 728 743 differentiation differentiation NN 743 744 , , , 745 747 we we PRP 748 757 generated generate VBD 758 762 cell cell NN 763 769 clones clone NNS 770 780 expressing express VBG 781 790 different different JJ 791 797 levels level NNS 798 800 of of IN 801 811 HSF2-alpha HSF2-alpha NNP 812 815 and and CC 816 825 HSF2-beta HSF2-beta NNP 825 826 . . . 827 829 We we PRP 830 834 show show VBP 835 839 that that IN 840 842 in in IN 843 851 parental parental JJ 852 856 K562 k562 NN 857 862 cells cell NNS 862 863 , , , 864 867 the the DT 868 878 HSF2-alpha HSF2-alpha NNP 879 886 isoform isoform NN 887 889 is be VBZ 890 903 predominantly predominantly RB 904 913 expressed express VBN 914 917 and and CC 918 922 HSF2 hsf2 NN 923 926 can can MD 927 929 be be VB 930 939 activated activate VBN 940 944 upon upon IN 945 950 hemin hemin NN 951 960 treatment treatment NN 960 961 . . . 962 964 In in IN 965 973 contrast contrast NN 973 974 , , , 975 979 when when WRB 980 989 HSF2-beta HSF2-beta NNP 990 992 is be VBZ 993 1002 expressed express VBN 1003 1005 at at IN 1006 1012 levels level NNS 1013 1022 exceeding exceed VBG 1023 1028 those those DT 1029 1031 of of IN 1032 1042 endogenous endogenous JJ 1043 1053 HSF2-alpha HSF2-alpha NNP 1053 1054 , , , 1055 1058 the the DT 1059 1072 hemin-induced hemin-induced JJ 1073 1076 DNA dna NN 1077 1084 binding binding NN 1085 1093 activity activity NN 1094 1097 and and CC 1098 1111 transcription transcription NN 1112 1114 of of IN 1115 1119 heat heat NN 1120 1125 shock shock NN 1126 1131 genes gene NNS 1132 1135 are be VBP 1136 1145 repressed repress VBN 1145 1146 , , , 1147 1154 whereas whereas IN 1155 1169 overexpression overexpression NN 1170 1172 of of IN 1173 1183 HSF2-alpha HSF2-alpha NNP 1184 1191 results result VBZ 1192 1194 in in IN 1195 1197 an an DT 1198 1206 enhanced enhance VBN 1207 1212 hemin hemin NN 1213 1221 response response NN 1221 1222 . . . 1223 1234 Furthermore furthermore RB 1234 1235 , , , 1236 1239 the the DT 1240 1253 hemin-induced hemin-induced JJ 1254 1266 accumulation accumulation NN 1267 1269 of of IN 1270 1276 globin globin NN 1276 1277 , , , 1278 1283 known know VBN 1284 1286 as as IN 1287 1288 a a DT 1289 1295 marker marker NN 1296 1298 of of IN 1299 1308 erythroid erythroid JJ 1309 1324 differentiation differentiation NN 1324 1325 , , , 1326 1328 is be VBZ 1329 1338 decreased decrease VBN 1339 1341 in in IN 1342 1347 cells cell NNS 1348 1362 overexpressing overexpresse VBG 1363 1372 HSF2-beta HSF2-beta NNP 1372 1373 . . . 1374 1376 We we PRP 1377 1384 suggest suggest VBP 1385 1389 that that IN 1390 1399 HSF2-beta HSF2-beta NNP 1400 1404 acts act VBZ 1405 1407 as as IN 1408 1409 a a DT 1410 1418 negative negative JJ 1419 1428 regulator regulator NN 1429 1431 of of IN 1432 1436 HSF2 hsf2 NN 1437 1445 activity activity NN 1446 1452 during during IN 1453 1467 hemin-mediated hemin-mediated JJ 1468 1477 erythroid erythroid JJ 1478 1493 differentiation differentiation NN 1494 1496 of of IN 1497 1501 K562 k562 NN 1502 1507 cells cell NNS 1507 1508 . . .