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Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping

The F-actin binding domains of gelsolin and alpha-actinin compete for the same site on actin filaments with similar binding affinities. Both contain tandem repeats of approximately 125 amino acids, the first of which is shown to contain the actin-binding site. We have replaced the F-actin binding do...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1992
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289707/
https://www.ncbi.nlm.nih.gov/pubmed/1331120
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description The F-actin binding domains of gelsolin and alpha-actinin compete for the same site on actin filaments with similar binding affinities. Both contain tandem repeats of approximately 125 amino acids, the first of which is shown to contain the actin-binding site. We have replaced the F-actin binding domain in the NH2-terminal half of gelsolin by that of alpha-actinin. The hybrid severs filaments almost as efficiently as does gelsolin or its NH2-terminal half, but unlike the latter, requires calcium ions. The hybrid binds two actin monomers and caps the barbed ends of filaments in the presence or absence of calcium. The cap produced by the hybrid binds with lower affinity than that of gelsolin and is not stable: It dissociates from filament ends with a half life of approximately 15 min. Although there is no extended sequence homology between these two different F-actin binding domains, our experiments show that they are functionally equivalent and provide new insights into the mechanism of microfilament severing.
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spelling pubmed-22897072008-05-01 Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping J Cell Biol Articles The F-actin binding domains of gelsolin and alpha-actinin compete for the same site on actin filaments with similar binding affinities. Both contain tandem repeats of approximately 125 amino acids, the first of which is shown to contain the actin-binding site. We have replaced the F-actin binding domain in the NH2-terminal half of gelsolin by that of alpha-actinin. The hybrid severs filaments almost as efficiently as does gelsolin or its NH2-terminal half, but unlike the latter, requires calcium ions. The hybrid binds two actin monomers and caps the barbed ends of filaments in the presence or absence of calcium. The cap produced by the hybrid binds with lower affinity than that of gelsolin and is not stable: It dissociates from filament ends with a half life of approximately 15 min. Although there is no extended sequence homology between these two different F-actin binding domains, our experiments show that they are functionally equivalent and provide new insights into the mechanism of microfilament severing. The Rockefeller University Press 1992-11-02 /pmc/articles/PMC2289707/ /pubmed/1331120 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title_full Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title_fullStr Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title_full_unstemmed Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title_short Evidence for functional homology in the F-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
title_sort evidence for functional homology in the f-actin binding domains of gelsolin and alpha-actinin: implications for the requirements of severing and capping
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2289707/
https://www.ncbi.nlm.nih.gov/pubmed/1331120