β-Adrenoceptor Activation-Induced Placental Prorenin Secretion Is Mediated by Increased Renin Messenger RNA and Protein Synthesis

1997 ◽  
Vol 51 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Gregory J. Downing ◽  
Bingfang Yan ◽  
Alan M. Poisner
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Rna And Protein Synthesis

215 DISTRIBUTION OF DIMETHYLATION OF HISTONE H3K9 IS NOT AFFECTED BY DNA, MESSENGER RNA, AND PROTEIN SYNTHESIS IN PRONUCLEAR-STAGE PORCINE EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 205
Author(s):  
K. E. Park ◽  
R. Cabot
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Control Group ◽  
Mrna Synthesis ◽  
Treatment Groups ◽  
Asymmetrical Distribution ◽  
Rna And Protein Synthesis ◽  
H3k9 Dimethylation ◽  
Differential Localization

Methylation of the lysine 9 residue of histone H3 (H3K9) is linked with repression of transcription. Dimethylated H3K9 adopts a strict asymmetrical distribution in murine zygotes, with dimethylated H3K9 detectable only on maternally derived chromatin. In contrast, both male and female pronuclei in porcine zygotes can possess dimethylated H3K9; however, some asymmetry in H3K9 dimethylation exists between individual pronuclei, particularly in polyspermic embryos. The objective of this study was to determine the extent that DNA, mRNA, and protein synthesis serve in maintaining the asymmetrical distribution of dimethylated H3K9 in porcine zygotes. We hypothesized that the distribution of dimethylated H3K9 between individual pronuclei would not depend on alternations in chromatin structure induced by DNA or mRNA synthesis but would be affected by protein synthesis. To test this hypothesis, in vitro-matured porcine oocytes were fertilized in vitro, cultured in porcine zygote medium-3 containing 3 mg mL–1 of BSA, and allocated to 1 of 4 treatment groups: (1) incubation with 25 μg mL–1 of α-amanitin (α-AM), (2) incubation with 3 μg mL–1 of aphidicolin (APH), (3) incubation with 50 μg mL–1 of cycloheximide (CYC), and (4) nontreated controls. Embryos were removed from each treatment group at 10, 15, 20, and 25 h post gamete mixing, fixed, and processed to detect dimethylated H3K9 immunocytochemically. For monospermic embryos in the control group, 24% (7/29), 31% (8/26), 30% (7/24), and 20% (4/20) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the control group, 82% (32/39), 78% (31/40), 74% (28/38), and 65% (24/37) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the α-AM group, 29% (4/14), 14% (2/14), 8% (1/12), and 11% (1/9) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the α-AM group, 71% (15/21), 63% (12/19), 55% (10/18), and 47% (8/17) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the APH group, 31% (4/13), 23% (3/13), 23% (3/13), and 18% (2/11) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the APH group, 75% (15/20), 67% (12/18), 63% (12/19), and 56% (10/18) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For monospermic embryos in the CYC group, 33% (5/15), 25% (4/16), 14% (2/14), and 9% (1/11) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. For polyspermic embryos in the CYC group, 78% (18/23), 67% (16/24), 58% (14/24), and 59% (13/22) showed differential localization between pronuclei at 10, 15, 20, and 25 h, respectively. These results suggest that the distribution of dimethylated H3K9 between pronuclei is not affected by DNA, mRNA, or protein synthesis (P > 0.05), but is affected by the age of the pronuclei (P < 0.05).

scholarly journals Metabolic control mechanisms in mammalian systems. Hormonal regulation of phosphofructokinase in the rat prostate and seminal vesicles

1968 ◽  
Vol 110 (4) ◽  
pp. 703-711 ◽  
Author(s):  
Radhey L. Singhal ◽  
J. R. E. Valadares
Keyword(s):  
Protein Synthesis ◽  
Enzyme Activity ◽  
Hormonal Regulation ◽  
Messenger Rna ◽  
Time Course ◽  
Seminal Vesicles ◽  
Minimal Amount ◽  
Simultaneous Administration ◽  
Rna And Protein Synthesis ◽  
Phosphofructokinase Activity

1. The hormonal regulation of phosphofructokinase was investigated in the accessory reproductive organs of the orchidectomized rat. 2. Phosphofructokinase activities declined to 51% and 47% in the prostate and 9% and 6% of the normal values in seminal vesicles 4 and 8 weeks after castration respectively. Administration of testosterone (100μg./100g. body wt.) for 3 days reversed substantially the effects of orchidectomy, and phosphofructokinase activity increased to 173% in the prostate and 536% in seminal vesicles as compared with the values of castrated controls. 3. Time-course studies demonstrated that after a single injection of testosterone (5mg./100g. body wt.) phosphofructokinase activity was maximally elevated to 236% in the prostate and 342% in seminal vesicles at 24hr. 4. Dose–response studies revealed that 2·5mg. of testosterone propionate/100g. body wt. was the minimal amount necessary to induce significant increases in enzyme activity in both accessory sex organs; maximal increases were obtained with a dose of 5mg./100g. body wt. 5. The observed enzyme increases induced by testosterone were inhibited by the simultaneous administration of oestradiol-17β, and phosphofructokinase activity in this group of rats remained at 97% in the prostate and 137% of the control values in seminal vesicles. Oestradiol-17β by itself failed to produce any significant effect on enzyme activity in either of these secondary sexual tissues. 6. The nature of the testosterone-induced increases in phosphofructokinase activity was studied by using a variety of inhibitors of RNA and protein synthesis. Cycloheximide, 5-fluorouracil and ethionine largely blocked the androgen-stimulated rise in enzyme activity observed 24hr. after steroid injection. The inhibitory effect of ethionine was completely reversed by the simultaneous administration of methionine. 7. Actinomycin, which is known to inhibit the synthesis of messenger RNA as well as the synthesis of other cellular RNA fractions, when given simultaneously with the hormone, also inhibited the testosterone-induced increases in prostatic and seminal-vesicular phosphofructokinase. However, when the antibiotic was given 6 or 12hr. after injection of the steroid, practically no inhibition of phosphofructokinase induction was obtained. This indicates that, once the enzyme-forming machinery is turned on and allowed to operate for a few hours, actinomycin is incapable of reversing the hormone-induced enzyme responses. 8. The results presented suggest that new RNA and protein synthesis may be involved in the observed androgen-induced increases in phosphofructokinase activity in the prostate and seminal vesicles of the orchidectomized rat.

Changes in Ribosome Organization and Messenger RNA Abundance in Ripening Tomato Fruits

1984 ◽  
Vol 11 (3) ◽  
pp. 225 ◽  
Author(s):  
J Spiers ◽  
CJ Brady ◽  
D Grierson ◽  
E Lee
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Rna ◽  
Messenger Rna ◽  
In Vitro Translation ◽  
Translation System ◽  
Active Protein ◽  
Tomato Fruits ◽  
Rna And Protein Synthesis ◽  
Early Ripening

The involvement of RNA and protein synthesis in fruit ripening was investigated. Mature-green tomato fruits were found to contain about 30% of their ribosomal RNA in polyribosomes. At the 'breaker' or early ripening stage, about 50% of rRNA was in polyribosomes and this distribution of rRNA was maintained until fruits were fully ripe. The continued presence of polyribosomes is consistent with active protein synthesis persisting through and beyond the climacteric period when the wall-hydrolysing enzyme polygalacturonase accumulates and fruits soften, synthesize lycopene and undergo other ripening related changes. Poly(A)-containing RNA purified from polyribosomes extracted from individual fruits was used to prime the synthesis of [35S]methionine-labelled polypeptides by a wheat germ in vitro translation system. The pattern of polypeptides synthesized in response to RNA from mature-green fruits differed from that given by RNA from ripening fruits. The majority of changes were found to occur within approximately 48 h of the increase of ethylene synthesis and were apparent in all fruits with any pink or red colour. Similar results were obtained by translating total cellular RNA and total polyribosomal RNA indicating that the major RNA species shown in this study to change in abundance during ripening are polyadenylated, and hence most probably cytoplasmic, and do not accumulate as 'stored messages' outside of the polyribosomes. The differences between green and ripening fruits in polyribosome profiles were demonstrated in two cultivars of tomato. Differences in mRNA populations between green and ripe fruits were found in three cultivars.

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