Identification of a novel isoform of ZAP-70, truncated ZAP kinase

Hiroyuki Kuroyama, Tohru Ikeda, Michiyuki Kasai, Sho Yamasaki, Masashi Tatsumi, Masanori Utsuyama, Takashi Saito, Katsuiku Hirokawa

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    1 Citation (Scopus)


    We identified a novel cDNA encoding truncated ZAP-70, which lacked the SH2 domain and a part of interdomain B, and named it truncated ZAP kinase (TZK). TZK was expressed in the thymus, spleen, and lymph nodes with ZAP-70. TZK was expressed in CD44+CD25- thymocytes up to mature T cells, but ZAP-70 was not expressed in CD44+CD25- or CD44 +CD25+ thymocytes. ZAP-70 or TZK was transfected into P116 cells derived from a Jurkat T-cell line deficient in ZAP-70. The P116 cells with ZAP-70 induced the T-cell receptor-mediated signal transduction, but the cells expressing TZK did not. While ZAP-70 was accumulated at the immune synapse, TZK was not. Meanwhile, impaired phosphorylation of SLP-76, one of the substrates of ZAP-70, in P116 cells upon pervanadate stimulation was rescued in the cells expressing TZK. These findings show that TZK is a novel isoform of ZAP-70, which is expressed in pre-T-cell receptor-minus thymocytes and functions as a kinase not associated with T-cell receptor.

    Original languageEnglish
    Pages (from-to)935-941
    Number of pages7
    JournalBiochemical and Biophysical Research Communications
    Issue number4
    Publication statusPublished - Mar 19 2004

    All Science Journal Classification (ASJC) codes

    • Biophysics
    • Biochemistry
    • Molecular Biology
    • Cell Biology


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