65-kilodalton protein phosphorylated by interleukin 2 stimulation bears two putative actin-binding sites and two calcium-binding sites. Academic Article uri icon

Overview

abstract

  • We have previously characterized a 65-kilodalton protein (p65) as an interleukin 2 stimulated phosphoprotein in human T cells and showed that three endopeptide sequences of p65 are present in the sequence of l-plastin [Zu et al. (1990) Biochemistry 29, 1055-1062]. In this paper, we present the complete primary structure of p65 based on the cDNA isolated from a human T lymphocyte (KUT-2) cDNA library. Analysis of p65 sequences and the amino acid composition of cleaved p65 N-terminal peptide indicated that the deduced p65 amino acid sequence exactly coincides with that of l-plastin over the C-terminal 580 residues [Lin et al. (1988) Mol. Cell. Biol. 8, 4659-4668] and has a 57-residue extension at the N-terminus to l-plastin. Computer-assisted structural analysis revealed that p65 is a multidomain molecule involving at least three intriguing functional domains: two putative calcium-binding sites along the N-terminal 80 amino acid residues; a putative calmodulin-binding site following the calcium-binding region; and two tandem repeats of putative actin-binding domains in its middle and C-terminal parts, each containing approximately 240 amino acid residues. These results suggest that p65 belongs to actin-binding proteins.

authors

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

publication date

  • September 11, 1990

Research

keywords

  • Actins
  • Calcium
  • Interleukin-2
  • Phosphoproteins
  • T-Lymphocytes

Identity

Scopus Document Identifier

  • 0025046583

Digital Object Identifier (DOI)

  • 10.1021/bi00488a017

PubMed ID

  • 2252891

Additional Document Info

volume

  • 29

issue

  • 36