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Study · In vitro (cells) · 1995

1 result

Actin polymerization induced by GTP gamma S in permeabilized neutrophils is induced and maintained by free barbed ends.

Tardif M, Huang S, Redmond T, Safer D, Pring M, Zigmond SH

The Journal of biological chemistry1 Nov 1995Cited by 22 (Europe PMC)

PMID7499294 (opens in a new tab)DOI10.1074/jbc.270.47.28075 (opens in a new tab)PepBankPUB-07499294
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Summary

To address the mechanisms through which agonists stimulate actin polymerization, we examined the roles of monomer sequestering proteins and free barbed ends on actin polymerization induced by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) in neutrophils permeabilized with streptolysin O. Addition of profilin (without GTP gamma S) caused a net decrease in F-actin. Thus, merely making profilin available in the cell was not sufficient to induce actin polymerization. On the other hand, addition of profilin hardly affected the polymerization induced by GTP gamma S, while thymosin beta 4 or DNase I decreased this polymerization. These data suggested that GTP gamma S induced polymerization by increasing the availability of barbed ends. In the presence of cytochalasin B, profilin did inhibit polymerization induced by GTP gamma S, demonstrating that GTP gamma S did not inhibit profilin's monomer sequestering ability. The F-actin induced by GTP gamma S was not limited by a time-dependent loss of G-actin or G-proteins from permeabilized cells since, following stimulation with suboptimal concentrations of GTP gamma S, addition of more GTP gamma S induced further polymerization. Barbed ends remained free after F-actin reached plateau since (a) cytochalasin B caused depolymerization of induced F-actin and (b) profilin did not depolymerize induced F-actin unless the cells were first treated with cytochalasin to cap barbed ends. The data indicate that GTP gamma S maintains an increased level of F-actin by keeping at least a few barbed ends available for polymerization.
CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study1

1 result from studies that gave the peptide. No result from this study comes from people.

  1. 01LabIn vitro (cells)Mechanism

    In permeabilized neutrophils, added thymosin beta‑4, like DNase I, decreased actin polymerization induced by GTP gamma S.

    In plain wordsIn lab-treated white blood cells, added thymosin beta‑4, like DNase I, reduced actin assembly triggered by GTP gamma S.

    Peptide
    Thymosin beta-4 (human)
    Outcome
    DecreaseGTP gamma S-induced actin polymerization
    Study

    n: not reported in source

    neutrophils permeabilized with streptolysin O
    Outcome group
    Receptor activity and mechanism · Immune and inflammation
    Studied dose
    Dose not stated · in vitroAs given in this study.

    Source sentences

    Summary
    On the other hand, addition of profilin hardly affected the polymerization induced by GTP gamma S, while thymosin beta 4 or DNase I decreased this polymerization.
    1 context sentence
    Summary · context
    To address the mechanisms through which agonists stimulate actin polymerization, we examined the roles of monomer sequestering proteins and free barbed ends on actin polymerization induced by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) in neutrophils permeabilized with streptolysin O.

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Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 01:52 UTC

    Study results updated

  2. Version 1

    12 Oct 2026, 18:17 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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