0 7 Cloning clone VBG 8 9 a a DT 10 14 cDNA cdna NN 15 19 from from IN 20 25 human human JJ 26 30 NK/T NK/T NNP 31 36 cells cell NNS 37 42 which which WDT 43 48 codes cod VBZ 49 52 for for IN 53 54 a a DT 55 62 protein protein NN 63 67 with with IN 68 72 high high JJ 73 80 proline proline NN 81 88 content content NN 88 89 . . . 91 92 A a DT 93 97 cDNA cdna NN 98 103 clone clone NN 103 104 , , , 105 109 B4-2 B4-2 NNP 109 110 , , , 111 114 was be VBD 115 123 isolated isolate VBN 124 128 from from IN 129 130 a a DT 131 138 natural natural JJ 139 145 killer killer NN 146 147 ( ( ( 147 149 NK NK NNP 149 150 ) ) ) 151 156 minus minus CC 157 158 T t NN 159 163 cell cell NN 164 175 subtractive subtractive JJ 176 183 library library NN 183 184 . . . 185 188 The the DT 189 193 B4-2 b4-2 NN 194 199 clone clone NN 200 205 coded cod VBN 206 209 for for IN 210 212 an an DT 213 217 mRNA mrna NN 218 220 of of IN 221 225 2061 2061 CD 226 228 bp bp NN 229 231 in in IN 232 238 length length NN 238 239 . . . 240 242 It it PRP 243 250 encodes encode VBZ 251 252 a a DT 253 260 deduced deduce VBN 261 264 327 327 CD 265 267 aa aa JJ 268 275 protein protein NN 276 280 with with IN 281 282 a a DT 283 293 calculated calculate VBN 294 303 molecular molecular JJ 304 308 mass mass NN 309 311 of of IN 312 316 35.2 35.2 CD 317 320 kDa kda NN 320 321 . . . 322 331 Searching searching NN 332 334 of of IN 335 339 B4-2 b4-2 NN 340 343 DNA dna NN 344 347 and and CC 348 355 protein protein NN 356 365 sequences sequence NNS 366 373 against against IN 374 381 various various JJ 382 391 databases database NNS 392 400 revealed reveal VBD 401 403 no no DT 404 408 high high JJ 409 417 homology homology NN 418 420 to to TO 421 426 other other JJ 427 436 sequences sequence NNS 436 437 . . . 438 445 However however RB 445 446 , , , 447 451 B4-2 B4-2 NNP 452 455 has have VBZ 456 458 an an DT 459 468 unusually unusually RB 469 473 high high JJ 474 481 proline proline NN 482 489 content content NN 490 491 ( ( ( 491 493 13 13 CD 493 494 % % NN 494 495 ) ) ) 495 496 , , , 497 505 contains contain VBZ 506 507 a a DT 508 516 putative putative JJ 517 524 nuclear nuclear JJ 525 534 targeting targeting NN 535 543 sequence sequence NN 543 544 , , , 545 548 and and CC 549 552 has have VBZ 553 560 several several JJ 561 565 SPXX SPXX NNP 566 572 motifs motif NNS 573 578 which which WDT 579 582 are be VBP 583 593 frequently frequently RB 594 599 found find VBN 600 602 in in IN 603 607 gene gene NN 608 618 regulatory regulatory JJ 619 627 proteins protein NNS 627 628 . . . 629 632 One one CD 633 635 of of IN 636 639 the the DT 640 649 stretches stretch NNS 650 652 of of IN 653 661 prolines proline NNS 662 664 in in IN 665 669 B4-2 b4-2 NN 670 677 closely closely RB 678 687 resembles resemble VBZ 688 691 the the DT 692 698 ligand ligand NN 699 702 for for IN 703 711 proteins protein NNS 712 716 with with IN 717 720 SH3 sh3 NN 721 728 domains domain NNS 728 729 . . . 730 738 Northern Northern NNP 739 752 hybridization hybridization NN 753 757 data datum NNS 758 764 showed show VBD 765 769 that that IN 770 774 B4-2 b4-2 NN 775 777 is be VBZ 778 781 not not RB 782 783 a a DT 784 792 lymphoid lymphoid JJ 793 801 specific specific JJ 802 806 gene gene NN 807 810 and and CC 811 813 is be VBZ 814 823 expressed express VBN 824 826 in in IN 827 828 a a DT 829 837 hepatoma hepatoma NN 838 842 cell cell NN 843 847 line line NN 848 851 and and CC 852 856 also also RB 857 863 weakly weakly RB 864 875 transcribed transcribe VBN 876 878 or or CC 879 885 absent absent JJ 886 888 in in IN 889 890 a a DT 891 898 variety variety NN 899 901 of of IN 902 907 other other JJ 908 913 cells cell NNS 913 914 . . . 915 916 A a DT 917 927 polyclonal polyclonal JJ 928 937 antiserum antiserum NN 938 944 raised raise VBN 945 952 against against IN 953 964 recombinant recombinant JJ 965 969 B4-2 b4-2 NN 970 980 recognizes recognize VBZ 981 982 a a DT 983 988 32-34 32-34 CD 989 992 kDa kda NN 993 1000 protein protein NN 1001 1003 in in IN 1004 1015 lymphocytes lymphocyte NNS 1015 1016 . . .