Effect of protein synthesis inhibitors on the formation of crystalloid inclusions in the endoplasmic reticulum of beetroot cells

PROTOPLASMA ◽  
1971 ◽  
Vol 73 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Margaret E. Van Steveninck ◽  
R. F. M. Van Steveninck
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Protein Synthesis Inhibitors ◽  
Crystalloid Inclusions

Metabolic requirements for interactions between nuclear and cytoplasmic membranes in the repair of damaged Amoeba nuclei

1976 ◽  
Vol 21 (2) ◽  
pp. 291-302
Author(s):  
C.J. Flickinger
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Membrane Fusion ◽  
Energy Production ◽  
Rna Synthesis ◽  
Metabolic Inhibitors ◽  
Protein Synthesis Inhibitors ◽  
Nuclear Membranes ◽  
Cytoplasmic Membranes ◽  
Rna And Protein Synthesis

Amoeba nuclear envelopes were damaged using microsurgery, and metabolic requirements for the steps in their repair were studied, and my placing the cells in a solution containing one of several metabolic inhibitors. The first step in repair, the association of pieces of endoplasmic reticulum with holes in the nuclear membranes, appears to be a passive process since it was not affected by inhibitors of energy production, RNA synthesis, or protein synthesis. In contrast, fusion of pieces of endoplasmic reticulum with the nuclear membranes at the margins of the holes was blocked by KCN and dinitrophenol, indicating that membrane fusion requires energy derived from respiration, but RNA and protein synthesis inhibitors did not prevent fusion of pieces of endoplasmic reticulum with the nuclear membranes. The subsequent completion of repair and restoration of intact nuclear membranes was almost completely blocked by inhibitors of respiration, and it was reduced in the presence of actinomycin and emetine, suggesting that in addition to a requirement for energy, some later steps in the repair of the nuclear membranes require RNA and protein synthesis.

scholarly journals Protein synthesis inhibitors and the chemical chaperone TMAO reverse endoplasmic reticulum perturbation induced by overexpression of the iodide transporter pendrin

2005 ◽  
Vol 118 (8) ◽  
pp. 1577-1586 ◽  
Author(s):  
J. Shepshelovich ◽  
L. Goldstein-Magal ◽  
A. Globerson ◽  
P. M. Yen ◽  
P. Rotman-Pikielny ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Protein Synthesis Inhibitors ◽  
Chemical Chaperone

scholarly journals Intracellular localization of fibronectin by immunoelectron microscopy.

1980 ◽  
Vol 28 (9) ◽  
pp. 953-960 ◽  
Author(s):  
S S Yamada ◽  
K M Yamada ◽  
M C Willingham
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Intracellular Localization ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Protein Synthesis Inhibitors ◽  
Cultured Fibroblasts ◽  
Extracellular Glycoprotein

We have localized fibronectin, a major extracellular glycoprotein of cultured fibroblasts, in chick embryo fibroblasts at the ultrastructural level using affinity-purified antibodies to fibronectin. The use of a ferritin bridge procedure permitted quantitation of localization in various organelles. These results provide the first intracellular ultrastructural localization of fibronectin. Extracellular labeling was confined to aggregates and fibrils, with little or no labeling of the plasma membrane. The principal sites of intracellular localization were the rough endoplasmic reticulum and the Golgi apparatus. Treatment of cells with the protein synthesis inhibitors cycloheximide and pactamycin reduced fibronectin localization in the endoplasmic reticulum to 50% of normal levels. Removal of cycloheximide permitted recovery of labeling to 85% of control levels in the endoplasmic reticulum. Similar, but much reduced, changes also occurred in the Golgi apparatus.

Spatial localization of unknown proteins in the endoplasmic reticulum predicts functions

2007 ◽  
Vol 30 (4) ◽  
pp. 84
Author(s):  
Michael D. Jain ◽  
Hisao Nagaya ◽  
Annalyn Gilchrist ◽  
Miroslaw Cygler ◽  
John J.M. Bergeron
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Folding ◽  
Protein Synthesis ◽  
Protein Function ◽  
Protein Translocation ◽  
Spatial Localization ◽  
Predict Protein Function ◽  
Insight Into ◽  
Soluble Fractions ◽  
Er Membrane

Protein synthesis, folding and degradation functions are spatially segregated in the endoplasmic reticulum (ER) with respect to the membrane and the ribosome (rough and smooth ER). Interrogation of a proteomics resource characterizing rough and smooth ER membranes subfractionated into cytosolic, membrane, and soluble fractions gives a spatial map of known proteins involved in ER function. The spatial localization of 224 identified unknown proteins in the ER is predicted to give insight into their function. Here we provide evidence that the proteomics resource accurately predicts the function of new proteins involved in protein synthesis (nudilin), protein translocation across the ER membrane (nicalin), co-translational protein folding (stexin), and distal protein folding in the lumen of the ER (erlin-1, TMX2). Proteomics provides the spatial localization of proteins and can be used to accurately predict protein function.

Activation of bovine oocytes by protein synthesis inhibitors: new findings on the role of MPF/MAPKs†

2021 ◽  
Author(s):  
Cecilia Valencia ◽  
Felipe Alonso Pérez ◽  
Carola Matus ◽  
Ricardo Felmer ◽  
María Elena Arias
Keyword(s):  
Protein Synthesis ◽  
Kinase Activity ◽  
Cyclin B1 ◽  
Protein Synthesis Inhibitors ◽  
Vitro Fertilization ◽  
New Findings ◽  
Bovine Oocytes ◽  
Dependent Pathway

Abstract The present study evaluated the mechanism by which protein synthesis inhibitors activate bovine oocytes. The aim was to analyze the dynamics of MPF and MAPKs. MII oocytes were activated with ionomycin (Io), ionomycin+anisomycin (ANY) and ionomycin+cycloheximide (CHX) and by in vitro fertilization (IVF). The expression of cyclin B1, p-CDK1, p-ERK1/2, p-JNK, and p-P38 were evaluated by immunodetection and the kinase activity of ERK1/2 was measured by enzyme assay. Evaluations at 1, 4, and 15 hours postactivation (hpa) showed that the expression of cyclin B1 was not modified by the treatments. ANY inactivated MPF by p-CDK1Thr14-Tyr15 at 4 hpa (P < 0.05), CHX increased pre-MPF (p-CDK1Thr161 and p-CDK1Thr14-Tyr15) at 1 hpa and IVF increased p-CDK1Thr14-Tyr15 at 17 hours postfertilization (hpf) (P < 0.05). ANY and CHX reduced the levels of p-ERK1/2 at 4 hpa (P < 0.05) and its activity at 4 and 1 hpa, respectively (P < 0.05). Meanwhile, IVF increased p-ERK1/2 at 6 hpf (P < 0.05); however, its kinase activity decreased at 6 hpf (P < 0.05). p-JNK in ANY, CHX, and IVF oocytes decreased at 4 hpa (P < 0.05). p-P38 was only observed at 1 hpa, with no differences between treatments. In conclusion, activation of bovine oocytes by ANY, CHX, and IVF inactivates MPF by CDK1-dependent specific phosphorylation without cyclin B1 degradation. ANY or CHX promoted this inactivation, which seemed to be more delayed in the physiological activation (IVF). Both inhibitors modulated MPF activity via an ERK1/2-independent pathway, whereas IVF activated the bovine oocytes via an ERK1/2-dependent pathway. Finally, ANY does not activate the JNK and P38 kinase pathways.

scholarly journals 1202. Subinhibitory Concentrations of Omadacycline Inhibit Staphylococcus aureus Hemolytic Activity in Vitro

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S622-S623
Author(s):  
Alisa W Serio ◽  
S Ken Tanaka ◽  
Kelly Wright ◽  
Lynne Garrity-Ryan
Keyword(s):  
Staphylococcus Aureus ◽  
Protein Synthesis ◽  
Virulence Factors ◽  
Hemolytic Activity ◽  
Protein Biosynthesis ◽  
The United States ◽  
Aureus Strain ◽  
Protein Synthesis Inhibitors ◽  
Subinhibitory Concentrations

Abstract Background In animal models of Staphylococcus aureus infection, α-hemolysin has been shown to be a key virulence factor. Treatment of S. aureus with subinhibitory levels of protein synthesis inhibitors can decrease α-hemolysin expression. Omadacycline, a novel aminomethylcycline antibiotic in the tetracycline class of bacterial protein biosynthesis inhibitors, is approved in the United States for treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) in adults. This study was performed to determine the durability of inhibition and effect of subinhibitory concentrations of omadacycline on S. aureus hemolytic activity. Methods All experiments used the methicillin-sensitive S. aureus strain Wood 46 (ATCC 10832), a laboratory strain known to secrete high levels of α-hemolysin. Minimum inhibitory concentrations (MICs) of omadacycline and comparator antibiotics (tetracycline, cephalothin, clindamycin, vancomycin, linezolid) were determined. Growth of S. aureus with all antibiotics was determined and the percentage of hemolysis assayed. “Washout” experiments were performed with omadacycline only. Results S. aureus cultures treated with 1/2 or 1/4 the MIC of omadacycline for 4 hours showed hemolysis units/108 CFU of 47% and 59% of vehicle-treated cultures, respectively (Fig. 1A, 1B). In washout experiments, treatment with as little as 1/4 the MIC of omadacycline for 1 hour decreased the hemolysis units/108 CFU by 60% for 4 hours following removal of the drug (Table 1). Figure 1 Table 1 Conclusion Omadacycline inhibited S. aureus hemolytic activity in vitro at subinhibitory concentrations and inhibition was maintained for ≥ 4 hours after removal of extracellular drug (Fig. 2). The suppression of virulence factors throughout the approved omadacycline dosing interval, in addition to the in vitro potency of omadacycline, may contribute to the efficacy of omadacycline for ABSSSI and CABP due to virulent S. aureus. This finding may apply to other organisms and other virulence factors that require new protein synthesis to establish disease. Figure 2 Disclosures Alisa W. Serio, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) S. Ken Tanaka, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Kelly Wright, PharmD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder) Lynne Garrity-Ryan, PhD, Paratek Pharmaceuticals, Inc. (Employee, Shareholder)

Inhibition of atrial peptide secretion at different stages of the secretory process: Ca2+ dependence

1991 ◽  
Vol 261 (6) ◽  
pp. C1162-C1172 ◽  
Author(s):  
E. Page ◽  
J. Upshaw-Earley ◽  
G. E. Goings ◽  
D. A. Hanck
Keyword(s):  
Protein Synthesis ◽  
Brefeldin A ◽  
Atp Depletion ◽  
Secretory Process ◽  
Protein Synthesis Inhibitors ◽  
Large Reservoir ◽  
Secretory Rate ◽  
Vesicular Traffic ◽  
Dependent Inactivation

We have used a noncontracting in vitro preparation of stretched and unstretched rat atria to estimate contributions of constitutive and regulated pathways to the rates of stretch-augmented and basal secretion of immunoreactive atrial natriuretic peptide (ANP) and to examine effects of inhibition of the secretory sequence by 1) protein synthesis inhibitors, 2) disruption of forward vesicular traffic between endoplasmic reticulum and Golgi with brefeldin A (BFA, and 3) cellular ATP depletion. Protein synthesis inhibition with cycloheximide for 44 min slowed neither basal nor stretch-augmented ANP secretion but instead accelerated stretch-augmented secretion at low (but not at physiological) external Ca2+ concentration, suggesting that the constitutive component does not contribute substantially to either basal or stretch-augmented secretion. BFA, which disassembled Golgi cisternae, increased the stretch-augmented secretory rate via the regulated pathway and prevented Ca(2+)-dependent inactivation with time. Cellular ATP depletion rapidly and completely inhibited stretch-augmented secretion. We conclude that both basal and stretch-augmented utilize the energy-dependent regulated pathway, drawing on a large reservoir of concentrated prohormone stored in granules that is not detectably depleted during 44 min of stretch-augmented secretion at 37 degrees C.

Sign in / Sign up

Export Citation Format

Share Document