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Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein

Oocytes, notably those of amphibia, accumulate large pools of nonfilamentous ("soluble") actin, both in the cytoplasm and in the nucleoplasm, which coexist with extensive actin filament arrays in the cytoplasmic cortex. Because the regulation of oogenically accumulated actin is important i...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1988
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2115250/
https://www.ncbi.nlm.nih.gov/pubmed/2844829
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collection PubMed
description Oocytes, notably those of amphibia, accumulate large pools of nonfilamentous ("soluble") actin, both in the cytoplasm and in the nucleoplasm, which coexist with extensive actin filament arrays in the cytoplasmic cortex. Because the regulation of oogenically accumulated actin is important in various processes of oogenesis, egg formation, fertilization and early embryogenesis, we have purified and characterized the major actin-binding proteins present in oocytes of Xenopus laevis. Here we report that the major actin-binding component in the ooplasm, but not in the nucleus, is a polypeptide of Mr approximately 93,000 on SDS-PAGE that reduces actin polymerization in vitro in a Ca2+-dependent manner but promotes nucleation events, and also reduces the viscosity of actin polymers, indicative of severing activity. We have raised antibodies against the purified oocyte protein and show that it is different from villin, is also prominent in unfertilized eggs and early embryos and is very similar to a corresponding protein present in various tissues and in cultured cells, and appears to be spread over the cytoplasm. Using these antibodies we have isolated a cDNA clone from a lambda gt11 expression library of ovarian poly(A)+-RNA. Determination of the amino acid sequence derived from the nucleotide sequence, together with the directly determined sequence of the amino terminus of the native protein, has shown that this clone encodes the carboxy-terminal half of gelsolin. We conclude that gelsolin is the major actin-modulating protein in oogenesis and early embryogenesis of amphibia, and probably also of other species, that probably also plays an important role in the various Ca2+- dependent gelation and contractility processes characteristic of these development stages.
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spelling pubmed-21152502008-05-01 Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein J Cell Biol Articles Oocytes, notably those of amphibia, accumulate large pools of nonfilamentous ("soluble") actin, both in the cytoplasm and in the nucleoplasm, which coexist with extensive actin filament arrays in the cytoplasmic cortex. Because the regulation of oogenically accumulated actin is important in various processes of oogenesis, egg formation, fertilization and early embryogenesis, we have purified and characterized the major actin-binding proteins present in oocytes of Xenopus laevis. Here we report that the major actin-binding component in the ooplasm, but not in the nucleus, is a polypeptide of Mr approximately 93,000 on SDS-PAGE that reduces actin polymerization in vitro in a Ca2+-dependent manner but promotes nucleation events, and also reduces the viscosity of actin polymers, indicative of severing activity. We have raised antibodies against the purified oocyte protein and show that it is different from villin, is also prominent in unfertilized eggs and early embryos and is very similar to a corresponding protein present in various tissues and in cultured cells, and appears to be spread over the cytoplasm. Using these antibodies we have isolated a cDNA clone from a lambda gt11 expression library of ovarian poly(A)+-RNA. Determination of the amino acid sequence derived from the nucleotide sequence, together with the directly determined sequence of the amino terminus of the native protein, has shown that this clone encodes the carboxy-terminal half of gelsolin. We conclude that gelsolin is the major actin-modulating protein in oogenesis and early embryogenesis of amphibia, and probably also of other species, that probably also plays an important role in the various Ca2+- dependent gelation and contractility processes characteristic of these development stages. The Rockefeller University Press 1988-10-01 /pmc/articles/PMC2115250/ /pubmed/2844829 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
Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title_full Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title_fullStr Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title_full_unstemmed Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title_short Proteins regulating actin assembly in oogenesis and early embryogenesis of Xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
title_sort proteins regulating actin assembly in oogenesis and early embryogenesis of xenopus laevis: gelsolin is the major cytoplasmic actin-binding protein
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2115250/
https://www.ncbi.nlm.nih.gov/pubmed/2844829