Dataset Information

Methods to separate nuclear soluble fractions reflecting localizations in living cells.

ABSTRACT: To understand various intranuclear functions, it is important to know when, what, and how proteins enter the nucleus. Although many methods and commercial kits for nuclear fractionation have been developed, there are still no methods for obtaining a complete nuclear proteome. Soluble nuclear proteins are often lost during fractionation. We developed remarkably improved methods to obtain nuclear soluble fractions by optimizing the conditions of selective permeabilization of the plasma membrane. As a result, 10 million cells could be separated into the cytoplasmic and nuclear soluble fractions more precisely in a 1.5-mL test tube. Moreover, the addition of an inhibitor to prevent leakage from the nucleus retained small proteins in the nucleus. Because of the simple protocols and easy application for multiple samples, our methods are expected to be applied to various studies on spatiotemporal changes of dynamic nuclear proteins, such as signal transduction.

SUBMITTER: Ogawa Y

PROVIDER: S-EPMC8661538 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Methods to separate nuclear soluble fractions reflecting localizations in living cells.

Ogawa Yutaka Y Imamoto Naoko N

iScience 20211125 12

To understand various intranuclear functions, it is important to know when, what, and how proteins enter the nucleus. Although many methods and commercial kits for nuclear fractionation have been developed, there are still no methods for obtaining a complete nuclear proteome. Soluble nuclear proteins are often lost during fractionation. We developed remarkably improved methods to obtain nuclear soluble fractions by optimizing the conditions of selective permeabilization of the plasma membrane. A ...[more]

PMID: 34934922

Similar Datasets

Project description:BackgroundAggregation and cytotoxicity of mutant proteins containing an expanded number of polyglutamine (polyQ) repeats is a hallmark of several diseases, including Huntington's disease (HD). Within cells, mutant Huntingtin (mHtt) and other polyglutamine expansion mutant proteins exist as monomers, soluble oligomers, and insoluble inclusion bodies (IBs). Determining which of these forms constitute a toxic species has proven difficult. Recent studies support a role for IBs as a cellular coping mechanism to sequester levels of potentially toxic soluble monomeric and oligomeric species of mHtt.Methodology/principal findingsWhen fused to a fluorescent reporter (GFP) and expressed in cells, the soluble monomeric and oligomeric polyglutamine species are visually indistinguishable. Here, we describe two complementary biophysical fluorescence microscopy techniques to directly detect soluble polyglutamine oligomers (using Htt exon 1 or Htt(ex1)) and monitor their fates in live cells. Photobleaching analyses revealed a significant reduction in the mobilities of mHtt(ex1) variants consistent with their incorporation into soluble microcomplexes. Similarly, when fused to split-GFP constructs, both wildtype and mHtt(ex1) formed oligomers, as evidenced by the formation of a fluorescent reporter. Only the mHtt(ex1) split-GFP oligomers assembled into IBs. Both FRAP and split-GFP approaches confirmed the ability of mHtt(ex1) to bind and incorporate wildtype Htt into soluble oligomers. We exploited the irreversible binding of split-GFP fragments to forcibly increase levels of soluble oligomeric mHtt(ex1). A corresponding increase in the rate of IBs formation and the number formed was observed. Importantly, higher levels of soluble mHtt(ex1) oligomers significantly correlated with increased mutant cytotoxicity, independent of the presence of IBs.Conclusions/significanceOur study describes powerful and sensitive tools for investigating soluble oligomeric forms of expanded polyglutamine proteins, and their impact on cell viability. Moreover, these methods should be applicable for the detection of soluble oligomers of a wide variety of aggregation prone proteins.

Dataset Information

Methods to separate nuclear soluble fractions reflecting localizations in living cells.

Publications

Methods to separate nuclear soluble fractions reflecting localizations in living cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets