RP1, a new member of the adenomatous polyposis coli-binding EB1-like gene family, is differentially expressed in activated T cells.
Cross-linking of the CD3 and CD28 molecules on T lymphocytes represents one of the most effective signals for T lymphocyte activation and triggering of their cytotoxic effector function. To identify genes that are expressed in T cells after stimulation, mRNA from T lymphocytes that had been activated by the simultaneous stimulation of the CD3 and CD28 trigger molecules was transcribed for a differential mRNA display analysis into cDNA and was compared with cDNA from CD28- or CD3-activated or resting lymphocytes. Differential expression was confirmed subsequently by Northern blot analysis. One of the cDNA fragments expressed specifically in CD3- and CD28-activated T cells was designated RP1. The predictive protein-coding region of RP1 had a significant homology to members of the recently found adenomatous polyposis coli (APC) protein-binding EB1 gene family, which codes for yet unknown protein(s). Bacterially expressed RP1 protein revealed specific binding to wild-type but not to mutated APC protein. The rapid up-regulation of RP1 mRNA in properly activated T cells suggests that this gene might belong to the immediate/early gene family, which controls the signal transduction cascade downstream of the TCR. As the expression level of the RP1 gene in activated T cells and a spectrum of tumor-derived cell lines correlates with the proliferative status of the cells, members of the EB1-like gene family may not only be involved in the tumorigenesis of colorectal cancers but may also play a role in the proliferative control of normal cells.
Renner
C
C
Med. Klinik I, University of Saarlandes, Homburg, Germany.
Pfitzenmeier
J P
JP
Gerlach
K
K
Held
G
G
Ohnesorge
S
S
Sahin
U
U
Bauer
S
S
Pfreundschuh
M
M
D011125:Adenomatous Polyposis Coli / Q000235:genetics* / Q000276:immunology; D025601:Adenomatous Polyposis Coli Protein; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification; D005136:Eye Proteins; D005786:Gene Expression Regulation / Q000276:immunology*; D017491:Genes, APC / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000235:genetics*; D051379:Mice; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000276:immunology*; D011233:Precipitin Tests; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000302:isolation & purification; D014407:Tumor Cells, Cultured
D025601:Adenomatous Polyposis Coli Protein; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D005136:Eye Proteins; D008869:Microtubule-Associated Proteins; C120042:RP1 protein, human; D015534:Trans-Activators