Human T cell L-plastin bundles actin filaments in a calcium dependent manner

Yuziro Namba, Masaya Ito, Youli Zu, Katsuya Shigesada, Koscak Maruyama

Research output: Contribution to journalArticlepeer-review

117 Scopus citations


The amino acid sequences deduced from cDNA analyses revealed that human leucocyte L-plastin phosphorylated in response to interleukin 1, 2 closely resembles a chicken intestinal microvilli protein, fimbrin, that bundles actin filaments [de Arruda et al. (1990) J. Cell Biol. 111, 1069-1079]. In the present work, it was observed that unphosphorylated L-plastin isolated from human T cells bundled F-actin just as fimbrin does. L-Plastin acted on T cell β-actin, but hardly acted on muscle γ-actin or chicken gizzard α-actin, whereas fimbrin bundled muscle α-actin. Unlike fimbrin, L-plastin's actin-bundling action was strictly calcium-dependent: the bundles were formed at pCa 7, but not at pCa 6. Under suitable conditions, approximately one molecule of L-plastin bound to 8 molecules of actin monomer in the actin filament.

Original languageEnglish (US)
Pages (from-to)503-507
Number of pages5
JournalJournal of Biochemistry
Issue number4
StatePublished - Jan 1 1992

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


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