0 4 GrpL GrpL NNP 4 5 , , , 6 7 a a DT 8 20 Grb2-related grb2-related JJ 21 28 adaptor adaptor NN 29 36 protein protein NN 36 37 , , , 38 47 interacts interact VBZ 48 52 with with IN 53 59 SLP-76 SLP-76 NNP 60 62 to to TO 63 71 regulate regulate VB 72 79 nuclear nuclear JJ 80 86 factor factor NN 87 89 of of IN 90 99 activated activate VBN 100 101 T t NN 102 106 cell cell NN 107 117 activation activation NN 117 118 . . . 120 131 Propagation propagation NN 132 134 of of IN 135 142 signals signal NNS 143 147 from from IN 148 151 the the DT 152 153 T t NN 154 158 cell cell NN 159 166 antigen antigen NN 167 175 receptor receptor NN 176 177 ( ( ( 177 180 TCR TCR NNP 180 181 ) ) ) 182 190 involves involve VBZ 191 192 a a DT 193 199 number number NN 200 202 of of IN 203 210 adaptor adaptor NN 211 220 molecules molecule NNS 220 221 . . . 222 225 SH2 sh2 NN 226 243 domain-containing domain-containing JJ 244 251 protein protein NN 252 254 76 76 CD 255 256 ( ( ( 256 262 SLP-76 slp-76 NN 262 263 ) ) ) 264 273 interacts interact VBZ 274 278 with with IN 279 282 the the DT 283 290 guanine guanine NN 291 301 nucleotide nucleotide NN 302 310 exchange exchange NN 311 317 factor factor NN 318 321 Vav Vav NNP 322 324 to to TO 325 333 activate activate VB 334 337 the the DT 338 345 nuclear nuclear JJ 346 352 factor factor NN 353 355 of of IN 356 365 activated activate VBN 366 371 cells cell NNS 372 373 ( ( ( 373 378 NF-AT NF-AT NNP 378 379 ) ) ) 379 380 , , , 381 384 and and CC 385 388 its its PRP$ 389 399 expression expression NN 400 402 is be VBZ 403 411 required require VBN 412 415 for for IN 416 422 normal normal JJ 423 424 T t NN 425 429 cell cell NN 430 441 development development NN 441 442 . . . 443 445 We we PRP 446 452 report report VBP 453 456 the the DT 457 464 cloning cloning NN 465 468 and and CC 469 485 characterization characterization NN 486 488 of of IN 489 490 a a DT 491 496 novel novel JJ 497 506 Grb2-like grb2-like JJ 507 514 adaptor adaptor NN 515 523 molecule molecule NN 524 534 designated designate VBN 535 537 as as IN 538 550 Grb2-related grb2-related JJ 551 558 protein protein NN 559 561 of of IN 562 565 the the DT 566 574 lymphoid lymphoid JJ 575 581 system system NN 582 583 ( ( ( 583 587 GrpL GrpL NNP 587 588 ) ) ) 588 589 . . . 590 600 Expression expression NN 601 603 of of IN 604 608 GrpL GrpL NNP 609 611 is be VBZ 612 622 restricted restricted JJ 623 625 to to TO 626 639 hematopoietic hematopoietic JJ 640 647 tissues tissue NNS 647 648 , , , 649 652 and and CC 653 655 it it PRP 656 658 is be VBZ 659 672 distinguished distinguish VBN 673 677 from from IN 678 682 Grb2 grb2 NN 683 685 by by IN 686 692 having have VBG 693 694 a a DT 695 707 proline-rich proline-rich JJ 708 714 region region NN 714 715 . . . 716 720 GrpL GrpL NNP 721 724 can can MD 725 727 be be VB 728 748 coimmunoprecipitated coimmunoprecipitate VBN 749 753 with with IN 754 760 SLP-76 SLP-76 NNP 761 764 but but CC 765 768 not not RB 769 773 with with IN 774 778 Sos1 Sos1 NNP 779 781 or or CC 782 786 Sos2 sos2 NN 787 791 from from IN 792 798 Jurkat Jurkat NNP 799 803 cell cell NN 804 811 lysates lysate NNS 811 812 . . . 813 815 In in IN 816 824 contrast contrast NN 824 825 , , , 826 830 Grb2 Grb2 NNP 831 834 can can MD 835 837 be be VB 838 858 coimmunoprecipitated coimmunoprecipitate VBN 859 863 with with IN 864 868 Sos1 Sos1 NNP 869 872 and and CC 873 877 Sos2 Sos2 NNP 878 881 but but CC 882 885 not not RB 886 890 with with IN 891 897 SLP-76 SLP-76 NNP 897 898 . . . 899 907 Moreover moreover RB 907 908 , , , 909 932 tyrosine-phosphorylated tyrosine-phosphorylated JJ 933 944 LAT/pp36/38 lat/pp36/38 NN 945 947 in in IN 948 957 detergent detergent JJ 958 965 lysates lysate NNS 966 974 prepared prepare VBN 975 979 from from IN 980 988 anti-CD3 anti-cd3 JJ 989 999 stimulated stimulate VBN 1000 1001 T t NN 1002 1007 cells cell NNS 1008 1018 associated associate VBN 1019 1023 with with IN 1024 1028 Grb2 grb2 NN 1029 1032 but but CC 1033 1036 not not RB 1037 1041 GrpL GrpL NNP 1041 1042 . . . 1043 1048 These these DT 1049 1053 data datum NNS 1054 1060 reveal reveal VBP 1061 1064 the the DT 1065 1073 presence presence NN 1074 1076 of of IN 1077 1085 distinct distinct JJ 1086 1095 complexes complex NNS 1096 1105 involving involve VBG 1106 1110 GrpL GrpL NNP 1111 1114 and and CC 1115 1119 Grb2 grb2 NN 1120 1122 in in IN 1123 1124 T t NN 1125 1130 cells cell NNS 1130 1131 . . . 1132 1133 A a DT 1134 1144 functional functional JJ 1145 1149 role role NN 1150 1152 of of IN 1153 1156 the the DT 1157 1168 GrpL-SLP-76 GrpL-SLP-76 NNP 1169 1176 complex complex NN 1177 1179 is be VBZ 1180 1189 suggested suggest VBN 1190 1192 by by IN 1193 1196 the the DT 1197 1204 ability ability NN 1205 1207 of of IN 1208 1212 GrpL GrpL NNP 1213 1215 to to TO 1216 1219 act act VB 1220 1225 alone alone RB 1226 1228 or or CC 1229 1231 in in IN 1232 1239 concert concert NN 1240 1244 with with IN 1245 1251 SLP-76 SLP-76 NNP 1252 1254 to to TO 1255 1262 augment augment VB 1263 1268 NF-AT nf-at NN 1269 1279 activation activation NN 1280 1282 in in IN 1283 1289 Jurkat Jurkat NNP 1290 1291 T t NN 1292 1297 cells cell NNS 1297 1298 . . .