Influence of Neurosecretory Cells and of Corpus Allatum on Intestinal Protease Activity in the Adult Calliphora Erythrocephala MEIG

1963 ◽  
Vol 40 (2) ◽  
pp. 301-321
Author(s):  
ELLEN THOMSEN ◽  
IB MØLLER
Keyword(s):  
Protein Synthesis ◽  
Protease Activity ◽  
Proteolytic Enzymes ◽  
Specific Protein ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Minor Effect ◽  
Calliphora Erythrocephala ◽  
Sugar Water ◽  
The Mean

1. The protease activity of the adult Calliphora female measured on the first 5 days after emergence was found to be highly influenced by the diet, the activity of females fed on sugar, water and meat (meat-flies) being much higher than that of females fed only on sugar and water (sugar-flies). 2. The development of the enzyme(s) was found to be controlled by the medial neurosecretory cells (m.n.c.), the mean protease activity of females deprived of their m.n.c. only amounting to one-quarter to one-third of the maximum values for the meat-flies. 3. Implantation of corpora cardiaca-allata (presumably containing m.n.c. hormone) into females without m.n.c. raised the protease activity of these significantly, showing that the influence of the implanted organs must be hormonal. 4. The corpus allatum was found to have a certain, if minor, effect on the protease activity. 5. It is concluded that in Calliphora the eating of meat exerts its effect on the production of protease mainly indirectly by causing liberation of m.n.c. hormone into the blood. 6. As proteases are themselves proteins, the effect of the m.n.c. hormone on the production of proteolytic enzymes by the gut cells must be regarded as an effect on the specific protein synthesis of these cells. There is some evidence that the m.n.c. hormone might be involved in the regulation of protein synthesis in general.

Errata

1963 ◽  
Vol 40 (3) ◽  
pp. 403-403
Keyword(s):  
Protease Activity ◽  
Neurosecretory Cells ◽  
Corpus Allatum

‘Influence of neurosecretory cells and of corpus allatum on intestinal protease activity in the adult Calliphora erythrocephalaMeig’. Page 302, line 18 for 10°C. read -10°C. Page 306, explanation to Fig. 20 for --•--•--, read --·--

scholarly journals Urokinase upregulates matrix metalloproteinase-9 expression in THP-1 monocytes via gene transcription and protein synthesis

2002 ◽  
Vol 367 (3) ◽  
pp. 833-839 ◽  
Author(s):  
Mikhail MENSHIKOV ◽  
Eugenia ELIZAROVA ◽  
Karina PLAKIDA ◽  
Angelika TIMOFEEVA ◽  
Georgy KHASPEKOV ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Matrix Metalloproteinase ◽  
Gene Transcription ◽  
Proteolytic Enzymes ◽  
Protein Biosynthesis ◽  
Reverse Transcription Pcr ◽  
Mmp9 Expression ◽  
Type Plasminogen Activator ◽  
Cell Incubation ◽  
Regulation Of Activity

Urokinase-type plasminogen activator (uPA) is suggested to exert its proliferatory, migratory and invasive action through binding with its membrane receptor, promoting pericellular proteolysis and mediating cell signal transduction. One of the possible actions of urokinase can be related to the regulation of activity and/or the expression of proteolytic enzymes participating in extracellular matrix degradation. In the present study, the role of uPA in regulating matrix metalloproteinase (MMP) expression and release by the monocyte cell line THP-1 was investigated. Recombinant uPA induced the release of MMP9/gelatinase B, as detected by zymography and Western blotting, and this release was abolished by actinomycin D and cycloheximide (inhibitors of DNA transcription and protein synthesis) and partially suppressed by monensin (an inhibitor of secretion). Proteolytically inactive urokinase with substitution of His204 for Gln was able to reproduce about 70% of the effect induced by the wild-type recombinant uPA. The reverse transcription-PCR and Northern blot data indicated that the action of r-uPA on THP-1 cells resulted in formation of MMP9 mRNA, which depended on time, within 6—48h, of the cell incubation with r-uPA. These results suggest that urokinase upregulates MMP9 expression in monocytes via MMP9 gene transcription and protein biosynthesis.

Cell-free, protein-synthesizing system of photosynthetic and heterotrophic Rhodospirillum rubrum

1976 ◽  
Vol 22 (2) ◽  
pp. 304-308
Author(s):  
C. T. Chow
Keyword(s):  
Protein Synthesis ◽  
Protease Activity ◽  
Rhodospirillum Rubrum ◽  
Chemical Compounds ◽  
Protein Synthesis Inhibitors ◽  
Free Protein ◽  
Two Systems ◽  
The Difference ◽  
Vitro Protein

An active in vitro protein-synthesizing system has been developed from Rhodospirillum rubrum grown under either photosynthetic or heterotrophic conditions. A protease activity has been found in both of these systems, and this activity can be readily inactivated by treating the cells with KCl and phenylmethyl sulfonylfluoride. The difference in protein-synthesizing activity between the photosynthetic and the heterotrophic systems has been tested in regard to the requirement of various chemicals and the response to protein synthesis inhibitors or various chemical compounds. It has been concluded that only minor differences in protein-synthesizing activity exist between these two systems.

The initial synthesis of haemoglobin in de-embryonated chick blastoderms.

Development ◽  
1964 ◽  
Vol 12 (4) ◽  
pp. 609-619
Author(s):  
Anna Hell
Keyword(s):  
Protein Synthesis ◽  
Deoxyribonucleic Acid ◽  
Primitive Streak ◽  
Specific Protein ◽  
In Vitro System ◽  
Embryonic Tissues ◽  
Different Types ◽  
Excellent Tool ◽  
Made In

Enormous progress has been made in the last few years towards the elucidation of the mechanism of protein synthesis, and great interest is centred on the steps leading to cellular differentiation and specific protein synthesis. We know that genetic information is passed on from one generation of cells to the next by deoxyribonucleic acid (DNA), and that this material directs all protein synthesis by the intermediary of the different types of ribonucleic acid (RNA). A simple in vitro system described by O'Brien (1959) seemed to offer an excellent tool for the study of the differentiation of the blood islands, and the initial formation of a well-known protein, haemoglobin (Hb), in chick embryonic tissues. After de-embryonation, chick blastoderms, from the stage of primitive streak onwards, can be cultured in vitro on a saline agar medium supplemented with glucose.

scholarly journals Ribosome Profiling Reveals HSP90 Inhibitor Effects on Stage-Specific Protein Synthesis in Leishmania donovani

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Eugenia Bifeld ◽  
Stephan Lorenzen ◽  
Katharina Bartsch ◽  
Juan-José Vasquez ◽  
T. Nicolai Siegel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Leishmania Donovani ◽  
Specific Protein ◽  
Ribosome Profiling ◽  
Severe Illness ◽  
Content Type ◽  
Hsp90 Activity

ABSTRACT The 90-kDa heat shock protein (HSP90) of eukaryotes is a highly abundant and essential chaperone required for the maturation of regulatory and signal proteins. In the protozoan parasite Leishmania donovani, causative agent of the fatal visceral leishmaniasis, HSP90 activity is essential for cell proliferation and survival. Even more importantly, its inhibition causes life cycle progression from the insect stage to the pathogenic, mammalian stage. To unravel the molecular impact of HSP90 activity on the parasites’ gene expression, we performed a ribosome profiling analysis of L. donovani, comparing genome-wide protein synthesis patterns in the presence and absence of the HSP90-specific inhibitor radicicol and an ectopically expressed radicicol-resistant HSP90 variant. We find that ribosome-protected RNA faithfully maps open reading frames and represents 97% of the annotated protein-coding genes of L. donovani. Protein synthesis was found to correlate poorly with RNA steady-state levels, indicating a regulated translation as primary mechanism for HSP90-dependent gene expression. The results confirm inhibitory effects of HSP90 on the synthesis of Leishmania proteins that are associated with the pathogenic, intracellular stage of the parasite. Those include heat shock proteins, redox enzymes, virulence-enhancing surface proteins, proteolytic pathways, and a complete set of histones. Conversely, HSP90 promotes fatty acid synthesis enzymes. Complementing radicicol treatment with the radicicol-resistant HSP90rr variant revealed important off-target radicicol effects that control a large number of the above-listed proteins. Leishmania lacks gene-specific transcription regulation and relies on regulated translation instead. Our ribosome footprinting analysis demonstrates a controlling function of HSP90 in stage-specific protein synthesis but also significant, HSP90-independent effects of the inhibitor radicicol. IMPORTANCE Leishmania parasites cause severe illness in humans and animals. They exist in two developmental stages, insect form and mammalian form, which differ in shape and gene expression. By mapping and quantifying RNA fragments protected by protein synthesis complexes, we determined the rates of protein synthesis for >90% of all Leishmania proteins in response to the inhibition of a key regulatory protein, the 90-kDa heat shock protein. We find that Leishmania depends on a regulation of protein synthesis for controlling its gene expression and that heat shock protein 90 inhibition can trigger the developmental program from insect form to mammalian form of the pathogen.

Effects of prolactin on testosterone-induced growth and protein synthesis in rat accessory sex glands

1983 ◽  
Vol 96 (3) ◽  
pp. 407-416 ◽  
Author(s):  
R. Jones ◽  
P. R. Riding ◽  
M. G. Parker
Keyword(s):  
Protein Synthesis ◽  
Total Protein ◽  
Sodium Dodecyl ◽  
Chronic Administration ◽  
Specific Protein ◽  
Ventral Prostate ◽  
Plasma Prolactin ◽  
Accessory Sex Glands ◽  
Caput Epididymidis

The relative importance of testosterone and prolactin in regulating growth and protein synthesis in rat accessory sex glands has been investigated. Protein synthesis was measured by incubating tissue minces in vitro with [35S]methionine and analysing labelled proteins on polyacrylamide gels containing sodium dodecyl sulphate. Plasma prolactin was assayed by radioimmunoassay. Results showed that castration for 8 days significantly reduced wet weights and total protein synthesis in the ventral prostate, dorsolateral prostate and caput epididymidis, but that these effects could be reversed by exogenous testosterone. Similarly, the specific incorporation of [35S]methionine into four polypeptides in the ventral prostate, two polypeptides in the dorsolateral prostate and two polypeptides in the caput epididymidis was lowered by castration but markedly stimulated by testosterone. Acute or chronic administration of 2-bromo-α-ergocryptine to animals in combination with testosterone had no significant effect on any of the parameters measured, although the drug reduced circulating prolactin to undetectable levels. In addition, exogenous prolactin given alone, or in combination with testosterone, to hypophysectomized rats had no effect on general or specific protein synthesis. The induction of hyperprolactinaemia in immature or mature rats with pituitary homographs had no effect on testosterone-stimulated growth of any accessory gland, although it caused a significant stimulation of total protein synthesis in the dorsolateral prostate and coagulating glands. However, this was a generalized effect as it did not increase the specific incorporation of [35S]methionine into androgen-dependent proteins. The results do not indicate a major role for prolactin in regulating androgen responsiveness of male accessory sex glands in the rat.

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