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The activities of the following enzymes have been determined in nuclei of quail oviducts in response to exogenous stimulation of the birds with diethylstilbestrol, used as an estrogen analogue and progesterone: DNA dependent DNA polymerase, DNA dependent RNA polymerase I and II and poly(adenosine diphosphate-ribose) [=poly(ADP-Rib)] polymerase.  相似文献   

3.
To elucidate the role of poly(ADP-Rib) in the nucleus, DNA synthesis and DNA fragmentation were studied in isolated nuclei of rat liver and rat ascites hepatoma AH-130 cells. Liver and hepatoma cell nuclei formed the same amount of poly(ADP-Rib) per mg of nuclear DNA from NAD. Preincubation of liver nuclei with NAD repressed DNA polymerase activity to 30% of that of the control, but preincubation of hepatoma cell nuclei with NAD did not affect DNA polymerase activity. It was also found that incubation of liver nuclei with NAD prevented the fragmentation of nuclear DNA which occurred without NAD. Incubation of hepatoma cell nuclei with or without NAD did not result in fragmentation of DNA. The role of endonuclease in primer formation for DNA synthesis is discussed.  相似文献   

4.
D B Jump  T R Butt  M Smulson 《Biochemistry》1979,18(6):983-990
The relationship between poly(adenosine diphosphate) ribosylation of nuclear proteins and functionally different forms of chromatin from mid-S-phase HeLa nuclei was investigated. The major observations emerging from this study were that unique nonhistone proteins were modified in mid-S-phase HeLa nuclei. The major acceptor for poly(adenosine diphosphate-ribose) [poly(ADP-Rib)] was an internucleosomal nonhistone protein (protein C; 125 000 molecular weight). Histones H3, H1, H2b, and H2a but not H4 were ADP-ribosylated in S-phase nuclei. Chromatin fragments preferentially released by micrococcal nuclease were enriched in nonhistone proteins, poly(ADP)-ribosylated nuclear proteins, poly(ADP-Rib) polymerase activity and nascent DNA from the DNA replicating fork. In extended forms of chromatin, contiguous to the DNA replicating fork, poly(ADP-Rib) polymerase was maximally active. However, in chromatin distal to the replicating fork (i.e., more condensed structures), nucleosomal histones and histone H1 were not significantly ADP-ribosylated, and poly(ADP-Rib) polymerase activity was depressed two- to threefold. The data suggest that a subset of nucleosomes in extended regions of chromatin is subject to extensive ADP ribosylation.  相似文献   

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Administration of diethylstilbestrol, an estrogen analogue, to immature female quails causes an increase of extractable DNA-dependent DNA polymerase activities from the oviduct. At least two forms of polymerases have been determined, a high molecular weight polymerase (210,000 daltons) and a low molecular weight polymerase (34,000 daltons) calculated from column chromatography Sephadex G-200. During the primary hormone stimulation the amount of extractable enzyme reaches a maximum on the fifth day after daily injections of the hormone. In the period of withdrawal the activities decrease and reach values similar to those determined in the unstimulated oviducts. During secondary stimulation the polymerase activities increase again the first day; subsequently the values decrease drastically. The alterations in enzyme activity correlate with the DNA synthesis in the oviduct, as measured by analytical determination of the DNA content.  相似文献   

7.
Purified rat liver nuclei were incubated with [14C]-NAD+ and the various nuclear protein fractions were separated. Forty per cent of the total radioactivity incorporated was associated with the histone fraction. Of this, about 50% was extracted with H1, in 0.5 N perchloric acid. When crude H1 was purified and fractionated into five different subfractions by chromatography on Bio-Rex 70, it was found that all the H1 subfractions contained radioactivity. This radioactive material was identified as oligomers of adenosine diphosphate ribose (ADP-Rib) with an average chain length which corresponded to trimers. The extent of the modification was dependent on the concentration of NAD+. About 60% of the H1 molecules were modified with a concentration of 1 mM NAD+. The presence of these oligomers of ADP-Rib introduced a large degree of microheterogeneity to H1 as detected by electrophoresis in polyacrylamide gels containing 2.5 M urea and 0.9 N acetic acid. Bands of H1 with 10 to 20% less mobility than the unmodified H1 were present. Also, as a consequence of large content of ADP-Rib, the absorption maximum shifted from 275 to 259 nm. The half-life of the bond between the oligomers of ADP-Rib and H1 was about 3 min at 37 degrees C in the presence of 0.1 N NaOH, and 10 m1 were modified. The site of ADP ribosylation in the NH2-terminal half was localized in the tryptic peptide extending from the NH2-terminal end to lysine 15. The site of modification of the COOH-erminal half was localized in the tryptic peptide which contained the only glutamic acid residue in this fragment of H1...  相似文献   

8.
The progesterone receptors from various stages of estrogen induced oviduct development, estrogen withdrawal, and secondary stimulation with estrogen were examined. The progesterone receptors were characterized for their biological function (i.e. capacity for nuclear translocation, nuclear binding, and effects on RNA polymerase II activity) as well as certain physical properties. The progesterone receptors from the undeveloped or partially developed oviducts (0 to 8 days of estrogen treatment) displayed little or no nuclear translocation and binding in vivo or in vitro. Similarly, progesterone showed little or no effect in vivo on RNA polymerase II activity at the early stages of development. As development progressed from 8 to 12 days of estrogen treatment, the above parameters rapidly increased to maximal levels and plateaued through day 23 of estrogen treatment. A marked decrease in these parameters occurred within 1 day of estrogen withdrawal. The reverse series of events occurred during secondary estrogen stimulation of 10-day-old withdrawn chicks. While the receptor concentrations increased rapidly to maximum values by 2 days of restimulation, receptor function did not return until day 4. Similarly, the effects of progesterone on RNA polymerase II activity reached maximal values by day 4. The progesterone receptor isolated from oviducts during development, estrogen withdrawal, and restimulation, displayed similar patterns of cell-free binding to chromatin and nucleoacidic protein as that observed in vivo supporting the nativeness of the in vitro binding assay. In contrast, the cell-free binding of these same progesterone receptor to pure DNA were not similar to the in vivo binding, i.e. no patterns (differences) in progesterone receptor binding were observed. These data support that protein DNA complexes and not pure DNA represent the native acceptor sites for oviduct progesterone receptor. Comparison of the progesterone receptor between the functional and nonfunctional states revealed no differences in the steroid affinity for the receptor, in the apparent pI of the species, or in the sedimentation of the receptor under high salt conditions. However, the nonfunctional receptors consistently displayed a deficiency in one of the two monomer molecular species (the B species) as determined by isoelectric focusing. These results suggest that both monomer species of progesterone receptor are required for biological activity. Interestingly, the 7S "aggregate" species of the progesterone receptor was constantly detected even when only one of the monomer species was present.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

9.
H Okazaki  C Niedergang  P Mandel 《Biochimie》1980,62(2-3):147-157
The mechanism of poly ADPR synthesis and the transfer of poly ADPR to histone H1 molecule by electrophoretically homogenous calf thymus poly ADPR polymerase containing DNA was examined. 1) An acid insoluble radioactive complex (I) was obtained after incubation of purified enzyme with [3H] NAD. The stability of (I) was examined by SDS-polyacrylamide gel electrophoresis. The complex (I) was stable against acid, SDS, urea, DNase and RNase, but labile against pronase, trypsin, alkali and snake venom phosphodiesterase treatment. The molecular weight of (I) was about 130 000 daltons estimated by SDS-gel electrophoresis. The radioactive products of successive alkali, venom phosphodiesterase and Pronase hydrolysis of (I) were PR-AMP and AMP. The mean chain length of poly ADPR of (I) was 20--30. These results suggest that the complex (I) is poly ADP-ribosylated poly ADPR polymerase. 2) Besides (I), a second radioactive peak (II) was observed when acid insoluble products obtained from an incubation mixture containing purified poly ADPR polymerase, [3H] NAD and purified histone H1 were analyzed on SDS-polyacrylamide gel electrophoresis. The molecular weight of (II) was estimated to be about 23 000 daltons. The complex (II) is eluted like histone H1 on CM-cellulose columns and hydrolyzed by alkali, trypsin and snake venom phosphodiesterase but not by DNase, or RNase. The comples (II) was extracted selectively by 5 per cent perchloric acid or 5 per cent trichloroacetic acid from mixture of (I) and (II). The mean chain length of poly ADPR of complex (II) and 5--20; these results suggest that the complex (II) is poly ADP-ribosylated histone H1. 3) Results 1) and 2) indicate that purified DNA containing, thus DNA independent, poly ADPR polymerase catalyzes two different reactions, the ADPR transfer onto the enzyme itself and onto histone H1 and the elongation of ADPR chains. Dimeric forms of ADP-ribosylated histone H1 was not observed. Free poly ADPR was observed only when very small quantities of enzyme were used for incubation.  相似文献   

10.
Summary Nuclei isolated from D. discoideum and incubated in vitro with 3H-NAD synthesise poly(ADP-Rib). The optimum incubation conditions for the poly(ADP-Rib) polymerase were determined. The Km of the enzyme is 18 m NAD and it is inhibited by nicotinamide. Most of the poly(ADP-Rib) synthesised is attached to nuclear proteins.  相似文献   

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A slight DNA topoisomerase I activity was detected in highly purified poly(ADP-Rib)polymerase prepared from calf thymus. This copurified activity was found to be suppressed under conditions where the poly(ADP-ribosylation) reaction occurs in the presence of NAD. Purified topoisomerase I from calf thymus was shown to be ADP-ribosylated by poly(ADP-Rib) polymerase purified from the same tissue. Poly(ADP-ribosylation) of topoisomerase I produces an inhibition of the enzymatic activity in parallel to the extent of ADP-ribosylation. The fact that a slight poly(ADP-Rib) polymerase activity was also found to copurify with a topoisomerase I preparation and that topoisomerase I activity can be modified by ADP-ribosylation, may suggest a spatial and functional correlation of these two enzymes in chromatin.  相似文献   

14.
Expression of cellular erb B protooncogene messenger RNAs has been analyzed in the oviducts of immature chicks during estrogen-promoted growth. Hybridization of oviduct total cellular RNA with viral-derived erb B oncogene probes demonstrated significant expression of c-erb B mRNA in oviduct cells of untreated chicks. Daily administration of estrogen (diethylstilbestrol) to chicks results in marked oviduct growth but did not appreciably affect expression levels of c-erb B messenger RNA in oviducts after 2, 4 or 6 days of treatment. Withdrawal of chicks from estrogen treatment resulted in termination of oviduct growth. However, c-erb B messenger RNAs were detectable in the nonproliferative tissue at 5 days after hormone withdrawal. Readministration of diethylstilbestrol, progesterone or diethylstilbestrol plus progesterone to hormone-withdrawn birds (secondary stimulation) also did not affect c-erb B messenger RNA levels in the oviduct. These results demonstrate significant expression of the cellular erb B (epidermal growth factor receptor) gene in the avian oviduct. However, EGF receptor messenger RNA synthesis is not modulated in the oviduct by steroid hormones.  相似文献   

15.
DNA polymerase α1, a subspecies of DNA polymerase α of Ehrlich ascites tumor cells, was associated with a novel RNA polymerase activity and utilized poly(dT) and single-stranded circular fd DNA as a template without added primer in the presence of ribonucleoside triphosphates and a specific stimulating factor. DNA synthesis in the above system was inhibited by the ATP analogue, 2′-deoxy-2′-azidoadenosine 5′-triphosphate more than the DNA synthesis with poly(dT)·oligo(rA) by DNA polymerase α1 and RNA synthesis by mouse RNA polymerases I and II. Kinetic analysis showed that the analogue inhibited DNA polymerase α1 activity on poly(dT) competitively with respect to ATP, suggesting that the analogue inhibited RNA synthesis by the associated RNA polymerase activity.  相似文献   

16.
A nuclear poly(A) polymerase has been isolated from oviducts of immature quails. It could be purified 4300-fold. The enzyme depends specifically on ATP as substrate and requires Mg2+. The most effective primer for the enzyme is a polynucleotide, isolated from oviduct tissue. A poly(A) sequence to a maximum of 60 AMP residues is covalently linked per primer molecule. The poly(A)-rich product of the enzymatic reaction can be annealed to oligo(dT)-cellulose. The purest fraction does not contain any detectable poly(A)-degrading enzyme activity. Only very low activities of RNA polymerase are present. The poly(A polymerase activity in the assay with ATP is reduced by the ATP analogue, beta, lambda-ATP-methylene-diphosphonate. Both K-m and V are lowered. The ATP analogue is incorporated to a smaller extent into the poly(A) sequence, synthesized by the enzyme. Several other analogues of adenine, adenine nucleosides and adenine nucleotides are without effect on the enzymatic reaction. By these properties poly(A) polymerase can be distinguished from RNA polymerases form I and form II, isolated from the same tissue. Actinomycin D and alpha-amanitin failed to inhibit poly(A) polymerase activity. The activity of poly(A) polymerase has been determined during primary stimulation with the estrogen analogue diethylstilbestrol (daily injection for 5 days), after withdrawal of the hormone for 17 days and after secondary stimulation with the hormone analogue. The enzyme activity does not change during primary stimulation, withdrawal of the hormone or secondary stimulation. However the activity of a poly(A) degrading enzyme, localized in the nucleus, is reduced in oviducts from hormone-treated quails.  相似文献   

17.
Incorporation of radioactive alanine into chromatin-bound subfractions of H1 histone was studied in HeLa cells synchronized by the double thymidine block technique. The subfractions were resolved into three chromatographic peaks by Biorex-70. In the period 5-7 h after release from the thymidine block, peaks I and III showed twice as much incorporation as they did in the period 1-3 h after release, whereas peak II showed three times the incorporation at 5-7 h that it did at 1- 3 h. Thus, the H1-histone subfraction in peak II appears in chromatin somewhat later in S phase than do the subfractions in Peaks I and III.  相似文献   

18.
The effects of estrogen and progesterone on the function of chick oviduct tubular gland cells have been studied. Such function, as measured by the increase in specific cell products such as lysozyme and ovalbumin, requires the continuous presence of estrogen or progesterone. Withdrawal of hormone results in a rapid cessation of function and an involution of the oviduct accompanied by rapid decreases in total weight, lysozyme, and RNA. During such involution, tubular gland cells per se persist, as evidenced by a lack of comparable decrease in total DNA content and by histological demonstration of tubular gland cells. When estrogen administration is reinstituted, preexisting tubular gland cells rapidly synthesize ovalbumin and lysozyme without requiring new DNA synthesis. Administration of progesterone also stimulates the function of such cells. Furthermore, the effects of estrogen and progesterone are synergistic on the synthesis of lysozyme and ovalbumin, whereas progesterone antagonizes the estrogen-evoked formation of tubular gland cells. It is suggested that such complex interactions of estrogen and progesterone on oviduct development and function result from differences in responsiveness of the various cell types present in the tissue.  相似文献   

19.
Chromatin-bound DNA-dependent RNA polymerase in developing pea cotyledons   总被引:1,自引:1,他引:1  
C. A. Cullis 《Planta》1976,131(3):293-298
Summary The pattern of cotyledon development in three varieties of Pisum sativum has been defined in terms of cell number, DNA and RNA content and chromatin, bound RNA polymerase activity. Variation was observed in the relative periods of growth by cell division and cell expansion between the three varieties. The mean DNA content per cotyledon cell during growth by cell expansion increased to approximately 50C in one variety, 30C in the second variety and 15C in the third variety. The pattern of chromatin-bound RNA polymerase activity during development suggested that some of the DNA above the 2C level may contribute to RNA synthesis in two of the three varieties studied. In the third variety the RNA polymerase activity decreases throughout the phase of increase in DNA per cell. The chromatin-bound RNA polymerase activity per cell was correlated with the rate of RNA increase per cell.  相似文献   

20.
Poly(ADP-ribose) polymerase is a chromosomal enzyme that is completely dependent on added DNA for activity. The ability of DNA molecules to activate the polymerase appears to be enhanced by the presence of DNA damage. In the present study, we used SV 40 DNA and SV 40 minichromosomes to determine whether different types of DNA damage and different chromosomal components affect stimulation of polymerase activity. Treatment of SV 40 minichromosomes with agents or conditions that induced single-strand breaks increased their ability to stimulate poly(ADP-ribose) synthesis. This stimulation was enhanced by addition of histone H1 at a ratio of 1 microgram of histone H1 to 1 microgram of DNA. Higher ratios of histone H1 to DNA suppressed the ability of SV 40 minichromosomes containing single-strand breaks to stimulate enzyme activity. Treatment of SV 40 minichromosomes or SV 40 DNA with HaeIII restriction endonuclease to produce double-strand breaks markedly stimulated poly(ADP-ribose) polymerase activity. The stimulation of poly(ADP-ribose) polymerase by double-strand breaks occurred in the absence of histone H1 and was further enhanced by adding histone H1 up to ratios of 2 to 1 relative to DNA. At higher ratios of histone H1 to DNA, the presence of the histone continued to enhance the poly(ADP-ribose) synthesis stimulated by double-strand breaks.  相似文献   

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