Cloned murine T200 (Ly-5) cDNA reveals multiple transcripts within B- and T-lymphocyte lineages.
The murine T200 family of cell-surface glycoproteins is expressed on hematopoietic lineage cell types in a developmentally regulated manner with different lymphocyte subpopulations expressing cross-reactive but structurally distinct forms. To investigate the differences between these forms and the regulation of these differences, murine T200 cDNA clones were isolated by using a probe obtained by subtractive hybridization. This procedure made use of a T200+ L-cell transfectant and the parent Ltk- cell line. The 1.9-kilobase (kb) cDNA clone was sequenced and found to contain the coding region of the COOH-terminal 331 amino acids and 0.9 kb of 3' untranslated region. Where the sequence overlapped with the rat sequence, 80-90% homology was observed. RNA blot analysis revealed that B-lineage cell lines express either a 5.6-kb or a 6.5-kb mRNA correlating to the size difference of the T200 glycoprotein synthesized. Similarly, in the T-cell lineage a helper T-cell clone and a cytotoxic T-cell clone express T200 transcripts of 5.6 kb and 5.9 kb, respectively, which correlate with the distinct sizes of their T200 glycoproteins. A T200-negative mutant of a T-cell line was found to express full-length T200 mRNA, although at a diminished level.
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D006649:Histocompatibility Antigens / Q000235:genetics*; D007739:L Cells / Q000378:metabolism; D017493:Leukocyte Common Antigens; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D013601:T-Lymphocytes / Q000378:metabolism*; D013937:Thymidine Kinase / Q000235:genetics; D014158:Transcription, Genetic
D006649:Histocompatibility Antigens; D008565:Membrane Proteins; D012333:RNA, Messenger; D013937:Thymidine Kinase; D017493:Leukocyte Common Antigens