An Early Stage of Cold Acclimation with Four Phases of Protein Synthesis in Crowns of Winter Wheat

1992 ◽  
Vol 56 (11) ◽  
pp. 1715-1720 ◽  
Author(s):  
Yusuke Matsuda ◽  
Tohru Okuda ◽  
Akira Yamanaka ◽  
Shonosuke Sagisaka
2000 ◽  
Vol 278 (3) ◽  
pp. R705-R711 ◽  
Author(s):  
T. A. McAllister ◽  
J. R. Thompson ◽  
S. E. Samuels

The effect of long-term cold exposure on skeletal and cardiac muscle protein turnover was investigated in young growing animals. Two groups of 36 male 28-day-old rats were maintained at either 5°C (cold) or 25°C (control). Rates of protein synthesis and degradation were measured in vivo on days 5, 10, 15, and 20. Protein mass by day 20 was ∼28% lower in skeletal muscle (gastrocnemius and soleus) and ∼24% higher in heart in cold compared with control rats ( P < 0.05). In skeletal muscle, the fractional rates of protein synthesis ( k syn) and degradation ( k deg) were not significantly different between cold and control rats, although k syn was lower (approximately −26%) in cold rats on day 5; consequent to the lower protein mass, the absolute rates of protein synthesis (approximately −21%; P < 0.05) and degradation (approximately −13%; P < 0.1) were lower in cold compared with control rats. In heart, overall, k syn(approximately +12%; P < 0.1) and k deg(approximately +22%; P < 0.05) were higher in cold compared with control rats; consequently, the absolute rates of synthesis (approximately +44%) and degradation (approximately +54%) were higher in cold compared with control rats ( P < 0.05). Plasma triiodothyronine concentration was higher ( P < 0.05) in cold compared with control rats. These data indicate that long-term cold acclimation in skeletal muscle is associated with the establishment of a new homeostasis in protein turnover with decreased protein mass and normal fractional rates of protein turnover. In heart, unlike skeletal muscle, rates of protein turnover did not appear to immediately return to normal as increased rates of protein turnover were observed beyond day 5. These data also indicate that increased rates of protein turnover in skeletal muscle are unlikely to contribute to increased metabolic heat production during cold acclimation.


1973 ◽  
Vol 13 (2) ◽  
pp. 403-413
Author(s):  
M. L. FENWICK ◽  
MARGARET J. WALL

Cytoplasmic extracts of HeLa cells made 1 to 2 h after infection with radioactive poliovirus contained 150-S virus particles and 130-S, perhaps partially disrupted, particles. The latter were resistant to RNase but sensitive to dodecylsulphate. Both particles were associated with fast sedimenting material from which they could be released by deoxycholate, but not by EDTA. In isopycnic gradients of sucrose in D2O the labelled particles formed a sharp band coincident with membrane-bound ribosomes at a density of 1.23 g cm-3. It is suggested that attachment of virus particles to endoplasmic reticulum may be an early stage in the infectious cycle, determining the site of subsequent steps. The inhibition of cellular protein synthesis that develops during infection affects membrane-bound as well as free polysomes and therefore does not determine the membrane-association of viral protein synthesis.


Author(s):  
J. M. Waller

Abstract A description is provided for Tilletia controversa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Aegilops, Agropyron, Alopecurus, Arrhenatherum, Beckmannia, Bromus, Dactylis, Elymus, Festuca, Holcus, Hordeum, Koehleria, Lolium, Poa, Secale, Triticum, Trisetum. DISEASE: Causes dwarf bunt of winter wheat, and occurs sporadically on many grasses. Occasionally infects winter barley. Infected plants develop chlorotic flecks at an early stage, are markedly stunted, and produce rather fat, persistently green ears with protuberant spikes caused by the bunt balls which fill the grain. As with T. caries (CMI Descriptions No. 719) and T. foetida (CMI Descriptions No. 720) the contents of the grain are converted to a mass of teliospores which constitute the bunt ball. GEOGRAPHICAL DISTRIBUTION: Europe (except Spain and UK); N. Africa, W. Asia, N. America, Argentina and Uruguay (CMI Map 297, ed. 2, 1968). TRANSMISSION: Teliospores are released when the grain is harvested and contaminate soil and seed. Soil-borne spores are the major source of inoculum for infecting crops which occurs between December and April in NW USA (43, 1295). Teliospores in bunt balls can remain viable in the soil for several years.


2020 ◽  
Vol 21 (11) ◽  
pp. 3820 ◽  
Author(s):  
Jia Xin Tang ◽  
Kyle Thompson ◽  
Robert W. Taylor ◽  
Monika Oláhová

The assembly of mitochondrial oxidative phosphorylation (OXPHOS) complexes is an intricate process, which—given their dual-genetic control—requires tight co-regulation of two evolutionarily distinct gene expression machineries. Moreover, fine-tuning protein synthesis to the nascent assembly of OXPHOS complexes requires regulatory mechanisms such as translational plasticity and translational activators that can coordinate mitochondrial translation with the import of nuclear-encoded mitochondrial proteins. The intricacy of OXPHOS complex biogenesis is further evidenced by the requirement of many tightly orchestrated steps and ancillary factors. Early-stage ancillary chaperones have essential roles in coordinating OXPHOS assembly, whilst late-stage assembly factors—also known as the LYRM (leucine–tyrosine–arginine motif) proteins—together with the mitochondrial acyl carrier protein (ACP)—regulate the incorporation and activation of late-incorporating OXPHOS subunits and/or co-factors. In this review, we describe recent discoveries providing insights into the mechanisms required for optimal OXPHOS biogenesis, including the coordination of mitochondrial gene expression with the availability of nuclear-encoded factors entering via mitochondrial protein import systems.


2019 ◽  
Vol 240 ◽  
pp. 153015 ◽  
Author(s):  
Nevena Djukić ◽  
Desimir Knežević ◽  
Danijel Pantelić ◽  
Dragan Živančev ◽  
Aleksandra Torbica ◽  
...  

1995 ◽  
Vol 269 (2) ◽  
pp. R229-R235 ◽  
Author(s):  
I. Guillen ◽  
M. Blanes ◽  
M. J. Gomez-Lechon ◽  
J. V. Castell

The purpose of this study was to investigate the significance of the sequential changes in proinflammatory cytokines observed in the plasma of patients early after myocardial infarct: a rise in interleukin (IL)-1 beta (308 +/- 126 vs. 141 +/- 78 pg/ml, P < 0.01) between 0 and 2 h followed by an IL-6 peak (49 +/- 24 vs. 14.5 +/- 13 pg/ml, P < 0.01) 4-9 h later. No significant changes in tumor necrosis factor-alpha (TNF-alpha) were observed at this early stage. The linkage between IL-1 beta and IL-6 secretions is supported by 1) the ability of patient's plasma drawn early after myocardial infarction to induce IL-6 mRNA and protein synthesis in cells that may be potential targets in vivo (fibroblasts and endothelial cells), 2) suppression of this activity by antibodies against IL-1 beta, and 3) a delay between IL-1 beta and IL-6 peaks in vivo (4-9 h), which is similar to the time required for maximal IL-6 production in IL-1 beta stimulated target cells in vitro (6 h). This sequential signaling might serve as the basis for an amplification mechanism of proinflammatory cytokines. In fact, a much greater synthesis of C-reactive protein was observed in hepatocytes when stimulated with conditioned medium of fibroblasts or endothelial cells that had previously been incubated with plasma of patients. The results of our work strongly suggest that, by inducing IL-6 in potential target cells, IL-1 beta could act as the primary, but indirect, signal that stimulates acute-phase protein synthesis after myocardial injury.


1988 ◽  
Vol 8 (8) ◽  
pp. 3311-3315 ◽  
Author(s):  
T Kaneko ◽  
T Watanabe ◽  
M Oishi

When mouse erythroleukemia (MEL) cells were incubated in the presence of chloramphenicol (a specific inhibitor for mitochondrial protein synthesis) during the early stage of in vitro erythroid differentiation, the number of induced erythroid cells was greatly reduced. By use of cell fusion between two genetically marked MEL cells, this finding was further investigated. We found that the drug, along with other agents which inhibit mitochondrial protein synthesis, blocked the induction and turnover of the DMSO-inducible intracellular-erythroid-inducing activity (differentiation-inducing factor II) in a manner similar to that of cycloheximide, an inhibitor for nuclear protein synthesis. The inhibitory effect was confirmed by directly assaying differentiation-inducing factor II in the cell extracts. These results strongly suggest that mitochondrial protein synthesis is closely associated with in vitro erythroid differentiation of MEL cells.


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