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The actin filament-severing domain of plasma gelsolin
Gelsolin, a multifunctional actin-modulating protein, has two actin- binding sites which may interact cooperatively. Native gelsolin requires micromolar Ca2+ for optimal binding of actin to both sites, and for expression of its actin filament-severing function. Recent work has shown that an NH2-term...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1986
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2114347/ https://www.ncbi.nlm.nih.gov/pubmed/3021782 |
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collection | PubMed |
description | Gelsolin, a multifunctional actin-modulating protein, has two actin- binding sites which may interact cooperatively. Native gelsolin requires micromolar Ca2+ for optimal binding of actin to both sites, and for expression of its actin filament-severing function. Recent work has shown that an NH2-terminal chymotryptic 17-kD fragment of human plasma gelsolin contains one of the actin-binding sites, and that this fragment binds to and severs actin filaments weakly irrespective of whether Ca2+ is present. The other binding site is Ca2+ sensitive, and is found in a chymotryptic peptide derived from the COOH-terminal two- thirds of plasma gelsolin; this fragment does not sever F-actin or accelerate the polymerization of actin. This paper documents that larger thermolysin-derived fragments encompassing the NH2-terminal half of gelsolin sever actin filaments as effectively as native plasma gelsolin, although in a Ca2+-insensitive manner. This result indicates that the NH2-terminal half of gelsolin is the actin-severing domain. The stringent Ca2+ requirement for actin severing found in intact gelsolin is not due to a direct effect of Ca2+ on the severing domain, but indirectly through an effect on domains in the COOH-terminal half of the molecule to allow exposure of both actin-binding sites. |
format | Text |
id | pubmed-2114347 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1986 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21143472008-05-01 The actin filament-severing domain of plasma gelsolin J Cell Biol Articles Gelsolin, a multifunctional actin-modulating protein, has two actin- binding sites which may interact cooperatively. Native gelsolin requires micromolar Ca2+ for optimal binding of actin to both sites, and for expression of its actin filament-severing function. Recent work has shown that an NH2-terminal chymotryptic 17-kD fragment of human plasma gelsolin contains one of the actin-binding sites, and that this fragment binds to and severs actin filaments weakly irrespective of whether Ca2+ is present. The other binding site is Ca2+ sensitive, and is found in a chymotryptic peptide derived from the COOH-terminal two- thirds of plasma gelsolin; this fragment does not sever F-actin or accelerate the polymerization of actin. This paper documents that larger thermolysin-derived fragments encompassing the NH2-terminal half of gelsolin sever actin filaments as effectively as native plasma gelsolin, although in a Ca2+-insensitive manner. This result indicates that the NH2-terminal half of gelsolin is the actin-severing domain. The stringent Ca2+ requirement for actin severing found in intact gelsolin is not due to a direct effect of Ca2+ on the severing domain, but indirectly through an effect on domains in the COOH-terminal half of the molecule to allow exposure of both actin-binding sites. The Rockefeller University Press 1986-10-01 /pmc/articles/PMC2114347/ /pubmed/3021782 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 The actin filament-severing domain of plasma gelsolin |
title | The actin filament-severing domain of plasma gelsolin |
title_full | The actin filament-severing domain of plasma gelsolin |
title_fullStr | The actin filament-severing domain of plasma gelsolin |
title_full_unstemmed | The actin filament-severing domain of plasma gelsolin |
title_short | The actin filament-severing domain of plasma gelsolin |
title_sort | actin filament-severing domain of plasma gelsolin |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2114347/ https://www.ncbi.nlm.nih.gov/pubmed/3021782 |