Characterization of Interleukin 2 Stimulated 65-Kilodalton Phosphoprotein in Human T Cells

Youli Zu, Michiaki Kohno, Ichiro Kubota, Eisuke Nishida, Masao Hanaoka, Yuziro Namba

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


We have characterized the cellular proteins which are rapidly phosphorylated by interleukin 2 (IL 2) in a human IL 2 dependent cell line. When treated with IL 2, the phosphorylation of five proteins, 65, 50, 37, 24, and 21 kDa, was found in IL 2 dependent cell lines by two-dimensional gel electrophoretic analysis. After cell conversion from an IL 2 dependent state to an IL 2 independent state, one of the five phosphoproteins, the 65-kDa protein, became constitutively phosphorylated even without addition of IL 2. Also, in other IL 2 independent cell lines, such as KUT-2 and HUT-102, constitutive phosphorylation of the 65-kDa protein occurred without IL 2-stimulation. So our researchers were focused on biochemical characterization of the 65-kDa protein. It was found that the 65-kDa protein was one of the major cellular proteins by comparing the results of two-dimensional gel electrophoretic analysis of [32P]Pi-labeled and [3H]leucine-labeled cellular proteins and peptide mapping analysis. Subcellular fractionation studies indicated that the 65-kDa protein is a cytosol protein. The 65-kDa protein was purified from cytosol of a human T cell line, and its amino acid composition and amino acid sequences of its three oligopeptides were determined. It was found that the 65-kDa protein is identical with 1-plastin.

Original languageEnglish (US)
Pages (from-to)1055-1062
Number of pages8
Issue number4
StatePublished - Jan 1 1990

ASJC Scopus subject areas

  • Biochemistry


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