Transport of informosomes from isolated nuclei of regenerating rat liver

Schumm, Dorothy E.; Webb, Thomas E.

doi:10.1016/0006-291x(72)90847-9

Cited by 74 publications

(32 citation statements)

References 17 publications

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“…1 and 2). This supports the view (Agutter et al, 1976(Agutter et al, , 1979bIshikawa et al, 1978;Schumm & Webb, 1972) that the chelation model proposed by Chatterjee & Weissbach (1973) to explain the effect of ATP on RNA release is untenable. Increase of the Mg2+ concentration to 5mM (Ishikawa et al, 1978) did not significantly alter the results shown in Figs.…”

supporting

confidence: 83%

“…(4) ATP hydrolysis occurs, supplying the energy required for RNA transport across the nuclear envelope (Yu et al, 1972;Schumm & Webb, 1972Racevskis & Webb, 1974).…”

mentioning

confidence: 99%

“…The omission of spermidine from a nuclear incubation medium results in extensive non-specific leakage of nuclear contents (Yu et al, 1972;Schumm & Webb, 1972Sato et al, 1977a,b;Ishikawa et al, 1978), and this largely accounts for the differences in extent of DNA and RNA release into the media used by Agutter et al (1979b) [medium (a)] and Clawson et al (1978) [medium (b)] (Table 2). F-, which inhibits the NTPase (Table 2; cf.…”

mentioning

confidence: 99%

“…The RNA released into the medium used by Agutter et al (1979b) and into similar media (Schumm & Webb, 1972Ishikawa et al, 1978) is predominantly 8-18S material, and approx. 50% of it contains poly(A) tracts (Agutter & McCaldin, 1979).…”

mentioning

confidence: 99%

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Influence of nucleotides, cations and nucleoside triphosphatase inhibitors on the release of ribonucleic acid from isolated rat liver nuclei

Agutter¹

1980

Biochemical Journal

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The reasons underlying reported discrepancies in the effects of ATP, ADP, adenosine 5'-[Ify-methyleneltriphosphate, AMP + PP1, p-chloromercuribenzoate and F-on RNA efflux from isolated rat liver nuclei and on nuclear-envelope nucleoside triphosphatase activity were investigated. The stimulatory effect of ADP was attributed to myokinase activity associated with the nuclei; this activity was eluted on repeated washing with nuclear incubation medium. In the absence of Ca2+ and Mn2+, ATP, adenosine 5'-[Iymethyleneltriphosphate and AMP+ PP1 were found to promote release of both DNA and RNA. In the presence of 0.5 mM-Ca2+ and 0.3 mM-Mn2 , only ATP promoted RNA efflux to a significant extent. In the absence of spermidine, Ca2+ and Mn2+, nuclei released large quantities of DNA and RNA into the medium; this effect was promoted by p-chloromercuribenzoate. In the presence of the three cations, however, pchloromercuribenzoate inhibited RNA efflux. F-caused a slight leakage of DNA from nuclei. The results are discussed in terms of models for the effects of ATP and analogues on RNA efflux and nuclear stability.The stimulation of RNA release from isolated nuclei by ATP and related compounds has been investigated in several laboratories and the effect has been interpreted in at least four different ways.(1) The ATP chelates bivalent metal ions in the medium, promoting release of heterogeneous nuclear RNA-protein complexes from the chromatin (Ishi-

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supporting

confidence: 83%

“…(4) ATP hydrolysis occurs, supplying the energy required for RNA transport across the nuclear envelope (Yu et al, 1972;Schumm & Webb, 1972Racevskis & Webb, 1974).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Influence of nucleotides, cations and nucleoside triphosphatase inhibitors on the release of ribonucleic acid from isolated rat liver nuclei

Agutter¹

1980

Biochemical Journal

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“…Isolated nuclei from other systems have been used to great advantage in the study of several important problems: e.g. the study of the transcription of defined RNA species (15,23,25,30,34), the intranuclear metabolism and release of RNA (26), the post-transcriptional additions of poly(A) to HnRNA (16,32,33), the mechanisms involved in DNA replication (6,9,10,22), the modification of chromatin proteins and their role in gene expression (18,28,35,39), the preparation of high mol wt DNA (1), and enzyme localization (8,29). We have pursued the isolation of nuclei from soybean hypocotyl with the objective of isolating large quantities of "intact," biologically active nuclei to be used in studies on the auxin regulation of RNA synthesis.…”

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confidence: 99%

Isolation and Properties of Nuclei from Control and Auxin-treated Soybean Hypocotyl

Chen¹,

Lin²,

Chang³

et al. 1975

Plant Physiol.

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A quick procedure for the isolation of nuclei with good yield from soybean hypocotyl (Glycine max var. Wayne) was developed. The isolated nuclei appeared to retain their structural integrity. They were typically ellipsoidal with minima and maxima diameter of about 6 and 8 to 10 micrometers. While the nuclei were similar in size, the nucleoli were significantly larger in nuclei from auxin-treated tissue. The DNA content per nucleus was 4 ± 1 picograms for both untreated and auxin-treated tissues. The DNA:RNA :protein ratio of isolated nuclei in untreated and auxin-treated tissues was 1: 3.1: 11 and 1: 5.4: 21.7, respectively. The purified nuclei were active in RNA synthesis; the level of RNA polymerase II activity expressed in the nuclei from untreated tissue was 50 to 60% higher than RNA polymerase I. The nuclei from auxin-treated tissues contained about 2.5 times as much RNA polymerase I activity as nuclei from untreated tissue. The purified nuclei from both untreated and auxin-treated tissues were also active in the incorporation of 3H-TTP into DNA.thesis. Isolated nuclei thus are essential to the study of in vitro RNA synthesis if conditions relating to the in vivo state are to be approached. Isolated nuclei from other systems have been used to great advantage in the study of several important problems: e.g. the study of the transcription of defined RNA species (15,23,25,30,34), the intranuclear metabolism and release of RNA (26), the post-transcriptional additions of poly(A) to HnRNA (16,32,33), the mechanisms involved in DNA replication (6,9,10,22), the modification of chromatin proteins and their role in gene expression (18,28,35,39), the preparation of high mol wt DNA (1), and enzyme localization (8,29). We have pursued the isolation of nuclei from soybean hypocotyl with the objective of isolating large quantities of "intact," biologically active nuclei to be used in studies on the auxin regulation of RNA synthesis. In this report, we describe a procedure for isolating nuclei from control and 2, 4-D-treated soybean hypocotyl. The attendant RNA and DNA synthetic activities, gross morphology, and macromolecular composition are described. MATERIALS AND METHODSStudies on the mechanism of plant hormone action have received much attention in recent years. Hormones are involved in the regulation of many different physiological processes; some lines of evidence indicate that in several cases this regulation may involve the control of the transcription or translation process (17). Because it is generally difficult to isolate plant nuclei in sufficient yield for extensive biochemical work, the isolation of plant chromatin has been used routinely in the study of the influence of auxin on the transcription of RNA (11,24). Recent studies with soybean chromatin isolated by conventional methodology (13)

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Effect of physiological concentrations of insulin and antidiabetic drugs on RNA release from isolated liver nuclei

Schumm

Webb

1983

J of Cellular Biochemistry

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The addition of 10-"M insulin to a cell-free system from rat liver promotes the release of messengerlike RNA from isolated prelabeled nuclei. The stimulation was similar whether the nuclei were preincubated with insulin, or if insulin was added directly to the cell-free system with or without a protease inhibitor. Dot blot hybridization using cloned cDNA for a2,-globulin mRNA showed that this was one of the messages whose release was enhanced by insulin. Nuclei isolated from rats treated with either of the antidiabetics tolbutamide or tolazamide showed no increase in RNA release in the presence of insulin over the concentration range 10-5-10-14 M . Furthermore, these nuclei did not release detectable levels of aZuglobulin mRNA.Key words: insulin, anti-diabetic drugs, tolazamide, tolbutamide, RNA transport, olz,-globulin mRNAInsulin is known to produce both immediate and late metabolic effects. The latter may be associated with the internalization of the hormone and its binding to high-affinity sites on the nuclear membrane [1,2]. Insulin binding to the nuclear membrane has been shown to stimulate the nuclear pore ATPase [3] and mRNA, but not rRNA, efflux from the nucleus to the cytoplasm in a cell-free system [4]. Since these latter experiments required insulin concentrations greater than physiological, it was of interest to determine the cause of the high insulin requirement and, if possible, to modify the system to respond to lower insulin levels.Among the specific long-term effects of insulin is the enhancement of the concentration of mRNA for albumin [5], az,-globulin [6], and tyrosine amino transferase [ 7 ] . If nuclei incubated in the cell-free system, which has previously been shown to release functional mRNA [8], are responding to insulin as do nuclei in vivo, it should be possible to detect an increased amount of these mRNAs in the RNAs released in vitro in the presence of insulin. The availability of a cloned cDNA to a2"-globulin mRNA [9] makes such a study feasible at this time.One of the acute in vivo effects of the oral antidiabetic drugs tolbutamide and tolazamide is to increase the levels of circulating insulin. These drugs have been

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Transport of informosomes from isolated nuclei of regenerating rat liver

Cited by 74 publications

References 17 publications

Influence of nucleotides, cations and nucleoside triphosphatase inhibitors on the release of ribonucleic acid from isolated rat liver nuclei

Influence of nucleotides, cations and nucleoside triphosphatase inhibitors on the release of ribonucleic acid from isolated rat liver nuclei

Isolation and Properties of Nuclei from Control and Auxin-treated Soybean Hypocotyl

Effect of physiological concentrations of insulin and antidiabetic drugs on RNA release from isolated liver nuclei

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