Characterization of interleukin 2-stimulated 65-kilodalton phosphoprotein in human T cells

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

doi:10.1021/bi00456a030

Cited by 35 publications

(20 citation statements)

References 36 publications

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“…Binding Partner-We found that L-plastin interacts with grancalcin and that Ca 2ϩ regulates the interaction in a negative fashion. L-plastin, like other plastin isoforms and fimbrin, is a mosaic protein containing 2 EF-hands, a calmodulin-binding domain, and two actin-binding domains (37). In resting cells, the Ca 2ϩ -binding sites are unoccupied, and most of Lplastin is involved in the cross-linking of F-actin fibers.…”

Section: Fig 7 Camentioning

confidence: 99%

Biochemical Characterization of the Penta-EF-hand Protein Grancalcin and Identification of L-plastin as a Binding Partner

Lollike

Johnsen

Durussel

et al. 2001

Journal of Biological Chemistry

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Grancalcin is a recently described 2؉ and subsequently exposes hydrophobic amino acid residues, which direct the protein to hydrophobic surfaces. By affinity chromatography of solubilized human neutrophils on immobilized grancalcin, L-plastin, a leukocyte-specific actin-bundling protein, was found to interact with grancalcin in a negative Ca 2؉ -dependent manner. This was substantiated by co-immunoprecipitation of grancalcin by anti-Lplastin antibodies and vice versa.

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Section: Fig 7 Camentioning

confidence: 99%

Biochemical Characterization of the Penta-EF-hand Protein Grancalcin and Identification of L-plastin as a Binding Partner

Lollike

Johnsen

Durussel

et al. 2001

Journal of Biological Chemistry

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“…I-Plastin has been shown to bind and bundle F-actin in vitro in a Ca2+-regulated manner (27,28). Its exclusive expression in leukocytes (29) and its phosphorylation in response to leukocyte activators such as interleukins 1 and 2 and phorbol esters (30,31) support the hypothesis that I-plastin has a role in cytoskeletal rearrangements during leukocyte activation.…”

mentioning

confidence: 90%

Bromophenacyl bromide binding to the actin-bundling protein l-plastin inhibits inositol trisphosphate-independent increase in Ca2+ in human neutrophils.

Rosales

Jones

McCourt

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

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Ligation of IgG Fc receptors on polymorphonuclear leukocytes causes an increase in the concentration of fre intracytoplasmic Ca2+ ([Ca2+1J which arises from release of intracellular stores but is Independent of inositol 1,4,5-trisphosphate. We found that bromophenacyl bromide (BPB), an alkylating agent which Inhibits leukocyte degranulation, adherence, and phagocytosis, inhibited IgG-stimulated These data suggest that the actin cytoskeleton is essential for signal tru ction from plasma membrane Fc receptors and that l-plastin has a critical role in activation of this pathway.The rise in intracytosolic Ca2+ concentration ([Ca2~+f) induced by Fc receptor (FcR) ligation is necessary for fusion of secretory granules with the plasma membrane, increased expression of other receptors, phagosome-lysosome fusion, and perhaps chemotaxis (1-6). Increases in [Ca2+]i can occur after ligation ofeither FcRII or FcRIII (7-9) and are produced entirely through release from intracellular stores, without a contribution from extracellular Ca2+ (7,9,10). This [Ca2+] rise, in contrast to fMet-Leu-Phe receptor stimulation, proceeds via a pertussis toxin-insensitive pathway which is independent of inositol 1,4,5-trisphosphate (IP3) generation (10). rise. These data demonstrate that rearrangements in the actin cytoskeleton triggered by FcR ligation are critical in release ofCa2+ from intracellular stores and suggest that I-plastin has a role in this process.MATERIALS AND METHODS General Methods. PMNs were purified and loaded with fura-2, fluorescence was measured, and [Ca2+]i was calculated exactly as described (7, 10, 18). All buffers contained 1.5 mM Ca2+. Agonists including aggregated IgG, immune complexes, and stock solutions of platelet-activating factor, fMet-Leu-Phe, and phorbol 12,13-dibutyrate were prepared, and phagocytosis of IgG-opsonized sheep erythrocytes was measured as described (7,10,18

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“…LPL is unique in the fimbrin family because it can become phosphorylated on serine in the headpiece region (19,20), suggesting that phosphorylation may be a specific mechanism of regulating LPL function in leukocytes. A variety of inflammatory mediators that activate ␤2 integrins such as chemokines, formylated bacterial peptides, cytokines, immune complexes, and phorbol 12-myristate 1-acetate (PMA), also induce LPL phosphorylation (19,(21)(22)(23)(24)(25). Despite its close association with activation of adhesion, LPL phosphorylation in PMN does not require ␤2 integrin expression (24), suggesting that its serine phosphorylation may precede ␣M␤2 activation.…”

mentioning

confidence: 99%

A role for the actin-bundling proteinl-plastin in the regulation of leukocyte integrin function

Jones

Wang

Turck

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

145

158

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Regulation of leukocyte integrin avidity is a crucial aspect of inf lammation and immunity. The actin cytoskeleton has an important role in the regulation of integrin function, but the cytoskeletal proteins involved are largely unknown. Because inf lammatory stimuli that activate integrin-mediated adhesion in human polymorphonuclear neutrophils (PMN) and monocytes cause phosphorylation of the actin-bundling protein L-plastin, we tested whether Lplastin phosphorylation was involved in integrin activation. L-plastin-derived peptides that included the phosphorylation site (Ser-5) rapidly induced leukocyte integrin-mediated adhesion when introduced into the cytosol of freshly isolated primary human PMN and monocytes. Substitution of Ala for Ser-5 abolished the ability of the peptide to induce adhesion. Peptide-induced adhesion was sensitive to pharmacologic inhibition of phosphoinositol 3-kinase and protein kinase C, but adhesion induced by a peptide containing a phosphoserine at position 5 was insensitive to inhibition. These data establish a novel role for L-plastin in the regulation of leukocyte adhesion and suggest that many signaling events implicated in integrin regulation act via induction of L-plastin phosphorylation.

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Characterization of interleukin 2-stimulated 65-kilodalton phosphoprotein in human T cells

Cited by 35 publications

References 36 publications

Biochemical Characterization of the Penta-EF-hand Protein Grancalcin and Identification of L-plastin as a Binding Partner

Biochemical Characterization of the Penta-EF-hand Protein Grancalcin and Identification of L-plastin as a Binding Partner

Bromophenacyl bromide binding to the actin-bundling protein l-plastin inhibits inositol trisphosphate-independent increase in Ca2+ in human neutrophils.

A role for the actin-bundling proteinl-plastin in the regulation of leukocyte integrin function

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