Diffusible and bound actin in nuclei of xenopus laevis oocytes

  title={Diffusible and bound actin in nuclei of xenopus laevis oocytes},
  author={Theodore G. Clark and Robert William Merriam},

Identification of a widespread nuclear actin binding protein

Two main components in Xenopus laevis oocytes with actin binding activities are identified; one of these activities is Ca2+-dependent, is located predominantly, if not exclusively, in the cytoplasm and is attributable to gelsolin, and the second component is a heterodimeric acting binding protein, which is markedly enriched in theuclei of oocytes and somatic cells of amphibia, but also occurs in nuclei of other vertebrate cells.

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

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.

Nuclear actin depolymerization in transcriptionally active avian and amphibian oocytes leads to collapse of intranuclear structures

In experiments with the actin depolymerizing drugs cytochalasin D and latrunculin A, it was showed that disassembly of nuclear actin polymers led to chromosome condensation and their transportation to a limited space within the oocyte nucleus, strongly resembled the process of karyosphere formation during oocyte growth.

Differences between nucleus and cytoplasm in the degree of actin polymerization

Nuclei from 35S-labeled amoebas were transplanted into unlabeled cells, and it was found that about 2/3 of the actin within the nucleus is pelletable, whereas only about 1/ 3 of the cytoplasmic actin ispelletable.

Chromatin tethering to the nuclear envelope by nuclear actin filaments: a novel role of the actin cytoskeleton in the Xenopus blastula

The Xenopus egg extract is devised and it is found that F-actin accumulates primarily at the sub-nuclear membranous region and is essential to maintain chromatin binding to the nuclear envelope in well-developed nuclei and contributes to chromosome alignment on the mitotic spindle at the following M phase.

Intranuclear injection of anti-actin antibodies into Xenopus oocytes blocks chromosome condensation

The results reported here suggest that actin is involved in the condensation of Xenopus chromosomes.

Nuclear actin and protein 4.1: Essential interactions during nuclear assembly in vitro

It is reported that structural protein 4.1 and actin colocalize in mammalian cell nuclei using fluorescence microscopy and, by higher-resolution detergent-extracted cell whole-mount electron microscopy, are associated on nuclear filaments.



Preparation and purification of polymerized actin from sea urchin egg extracts

  • R. Kane
  • Biology
    The Journal of cell biology
  • 1975
Although this procedure is similar to that used to polymerize tubulin from mammalian brain, sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows this gel to have actin as a major component and to contain no tubulin.

The germinal vesicle nucleus of Xenopus laevis oocytes as a selective storage receptacle for proteins

The possibility is discussed that the unique polypeptides of the nucleoplasm may be sequestered there by selective adsorption to or in the nuclear gel, and the solubility characteristics of the proteinaceous gel suggest a complex held together by salt, nonpolar, hydrogen, and possibly disulfide bonding.

Actin is the naturally occurring inhibitor of deoxyribonuclease I.

  • E. LazaridesU. Lindberg
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1974
The observation that actin can be isolated by DNase-agarose affinity chromatography provides a useful tool for the biochemical study of actin under different physiological conditions.

Nuclear proteins. II. Similarity of nonhistone proteins in nuclear sap and chromatin, and essential absence of contractile proteins from mouse liver nuclei

High resolution SDS slab gel electrophoresis has been used to examine the distribution of nonhistone proteins (NHP) in the saline-EDTA, Tris, and 0.35 M NaCl washes of isolated mouse liver nuclei and supports the conclusion that there are no clear differences between many nucleoplasmic and chromatin- bound nonhist one proteins.

Cytochalasin B inhibits actin-related gelation of HeLa cell extracts

The results indicate that actin and HMWP are partly disaggregated by cytochalasin treatment, and thus that their aggregation is related gelation.

Actin microheterogeneity in chick embryo fibroblasts.

  • P. RubensteinJ. Spudich
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1977
Identification of alpha-actin as the major actin from sarcomere-containing cells is confirmed by comparing embryonic chicken pre- and post-fusion myoblast cultures.

Nucleocytoplasmic exchange of macromolecules.

Protein migration into nuclei. II. Frog oocyte nuclei accumulate a class of microinjected oocyte nuclear proteins and exclude a class of microinjected oocyte cytoplasmic proteins

  • W. Bonner
  • Biology
    The Journal of cell biology
  • 1975
Radioactivity injected as nuclear contents or cytoplasm from Xenopus oocytes labeled with (35- S)methionine or (3-H)proline were reinjected into unlabeled oocytes (recipient oocytes) and found to enter and accumulate in the recipient oocyte nucleus.