scholarly journals Early development of protein metabolic perturbations in the liver and skeletal muscle of tumour-bearing rats. A model system for cancer cachexia

1987 ◽  
Vol 241 (1) ◽  
pp. 153-159 ◽  
Author(s):  
L Tessitore ◽  
G Bonelli ◽  
F M Baccino
Keyword(s):  
Protein Degradation ◽  
Degradation Rate ◽  
Gastrocnemius Muscle ◽  
Synthesis Rate ◽  
Ascites Hepatoma ◽  
Liver Growth ◽  
Metabolic Imbalance ◽  
Advanced Stages ◽  
Protein Degradation Rate

In rats into which a fast-growing ascites hepatoma (Yoshida AH-130) had been transplanted, tumour growth elicited a marked loss of body weight until the animal's death in about 2 weeks. Overall tissue protein metabolism was simultaneously studied in vivo in the gastrocnemius muscle and liver after labelling with [14C]bicarbonate. Early and progressive atrophy developed in the gastrocnemius muscle, the underlying metabolic imbalance being expressed by an elevation in the apparent protein-degradation rate, with no changes in the apparent synthesis rate. A transient hyperplastic response preceded waste in the liver, both states being associated with alterations in protein-degradation rate: an initial decrease during liver growth, then an acceleration as liver regressed. Protein-synthesis rates, virtually unchanged during liver growth, were elevated in the subsequent phase, although not sufficient to balance the enhanced breakdown. Thus, in the tumour host tissues examined, altered states of protein turnover appeared to result mostly from changes in rates of protein breakdown. In sharp contrast with the negative protein balance in the host, the ascites hepatoma cells had the ability to grow or at least, in advanced stages, to maintain a stationary state.

scholarly journals Defects in autophagy lead to selective in vivo changes in turnover of cytosolic and organelle proteins in Arabidopsis

2021 ◽  
Author(s):  
Lei Li ◽  
Chun Pong Lee ◽  
Akila Wijerathna-Yapa ◽  
Martyna Broda ◽  
Marisa S. Otegui ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Degradation Rate ◽  
T Complex ◽  
Autophagy Induction ◽  
Degradation Rates ◽  
Specific Proteins ◽  
Protein Degradation Rate ◽  
Synthesis And Degradation

AbstractIdentification of autophagic protein cargo in plants by their abundance in autophagy related genes (ATG) mutants is complicated by changes in both protein synthesis and protein degradation. To detect autophagic cargo, we measured protein degradation rate in shoots and roots of Arabidopsis atg5 and atg11 mutant plants. These data show that less than a quarter of proteins changing in abundance are probable cargo and revealed roles of ATG11 and ATG5 in degradation of specific cytosol, chloroplast and ER-resident proteins, and a specialized role for ATG11 in degradation of proteins from mitochondria and chloroplasts. Our data support a role for autophagy in degrading glycolytic enzymes and the chaperonin containing T-complex polypeptide-1 complex. Autophagy induction by Pi limitation changed metabolic profiles and the protein synthesis and degradation rates of atg5 and atg11 plants. A general decrease in the abundance of amino acids and increase in several secondary metabolites in autophagy mutants was consistent with altered catabolism and changes in energy conversion caused by reduced degradation rate of specific proteins. Combining measures of changes in protein abundance and degradation rates, we also identify ATG11 and ATG5 associated protein cargo of low Pi induced autophagy in chloroplasts and ER-resident proteins involved in secondary metabolism.Single Sentence SummaryProtein cargo of autophagy in plants can be discovered by identifying proteins that increase in abundance and decrease in degradation rate in mutants deficient in autophagy machinery

Impact of Weighing Procedures and Variation in Protein Degradation Rate on Measured Performance of Growing Lambs and Cattle

1983 ◽  
Vol 57 (5) ◽  
pp. 1276-1285 ◽  
Author(s):  
Rick Stock ◽  
Terry Klopfenstein ◽  
Dennis Brink ◽  
Steve Lowry ◽  
Dave Rock ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Degradation Rate ◽  
Protein Degradation Rate

Overexpression of Akt2 in Oral Cancer Cells is Due To Reduced Protein Degradation Rate

2015 ◽  
Vol 119 (3) ◽  
pp. e108
Author(s):  
Anak Iamaroon ◽  
Supansa Pata ◽  
Prakasit Archewa ◽  
Chayarop Supanachart ◽  
Sutthichai Krisanaprakornkit
Keyword(s):  
Oral Cancer ◽  
Protein Degradation ◽  
Cancer Cells ◽  
Degradation Rate ◽  
Oral Cancer Cells ◽  
Protein Degradation Rate

In vitro ruminal undegradable proteins of alfalfa cultivars

2000 ◽  
Vol 80 (2) ◽  
pp. 315-325 ◽  
Author(s):  
G. F. Tremblay ◽  
R. Michaud ◽  
G. Bélanger ◽  
K. B. McRae ◽  
H. V. Petit
Keyword(s):  
Protein Degradation ◽  
Dry Matter ◽  
Degradation Rate ◽  
Weight Ratio ◽  
Principal Component ◽  
Neutral Detergent Fiber ◽  
Cultivar Differences ◽  
Dry Matter Digestibility ◽  
Protein Degradation Rate

The quality of alfalfa would be greatly improved by an increase in its ruminal undegradable protein (RUP) concentration. Protein degradation rate (PDR), in vitro dry matter digestibility (IVDMD), leaf weight ratio (LWR), dry matter yield (DMY), total nitrogen (TN), in vitro RUP (expressed on both TN, RUP-TN, and dry matter basis, RUP-DM), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations were determined in 27 alfalfa cultivars. Cultivars were seeded in triplicate on 2 consecutive years and evaluated during the 2 subsequent production years with two harvests per year. Protein degradation rate and RUP-TN were determined using a ruminal inhibitor in vitro system. Data were averaged for spring growth, summer regrowth, and both harvests across 2 production years. Each of the three data sets was analyzed by ANOVA followed by a principal component analysis (PCA) on the ANOVA means. For the four-harvest data, cultivar differences were highly significant (P < 0.001) for all variates except for PDR (P = 0.07) and RUP-TN concentration (P = 0.10). The first PCA axis was largely defined positively by RUP-DM, IVDMD, TN, LWR, and RUP-TN, but negatively with ADF, NDF, PDR, and DMY. The second PCA axis defined a contrast between PDR versus RUP-TN, DMY, ADF, and NDF. Five cultivars were distinctive with high or low PCA scores in all three PCA. Rangelander and Heinrichs, along with Ultra, had low PDR; the first two cultivars had low DMY whereas Ultra was a medium-yielding cultivar. In contrast, Algonquin and Oneida VR had high PDR and medium DMY. While the first principal component (PC) indicated a general trend that low PDR and high RUP were associated with low-yielding cultivars, the second PC identified specific cultivars with both low PDR and high DMY. Therefore, selection for low PDR and high DMY is feasible. Key words: ruminal protein escape, dry matter digestibility, alfalfa

scholarly journals Protein Degradation Rate in Arabidopsis thaliana Leaf Growth and Development

2017 ◽  
Vol 29 (2) ◽  
pp. 207-228 ◽  
Author(s):  
Lei Li ◽  
Clark J. Nelson ◽  
Josua Trösch ◽  
Ian Castleden ◽  
Shaobai Huang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Degradation ◽  
Growth And Development ◽  
Degradation Rate ◽  
Leaf Growth ◽  
Protein Degradation Rate

Dependence of the period on the rate of protein degradation in minimal models for circadian oscillations

2009 ◽  
Vol 367 (1908) ◽  
pp. 4665-4683 ◽  
Author(s):  
Claude Gérard ◽  
Didier Gonze ◽  
Albert Goldbeter
Keyword(s):  
Circadian Rhythms ◽  
Protein Degradation ◽  
Degradation Rate ◽  
Protein Product ◽  
Degree Of Saturation ◽  
Minimal Models ◽  
Biochemical Processes ◽  
Parameter Values ◽  
Protein Degradation Rate ◽  
Clock Protein

Circadian rhythms, which occur spontaneously with a period of about 24 h in a variety of organisms, allow their adaptation to the periodic variations of the environment. These rhythms are generated by a genetic regulatory network involving a negative feedback loop on transcription. Mathematical models based on the negative autoregulation of gene expression by the protein product of a clock gene account for the occurrence of self-sustained circadian oscillations. These models differ by their degree of complexity and, hence, by the number of variables considered. Some of these models can be considered as minimal because they contain a reduced number of biochemical processes and variables capable of producing sustained oscillations. In three of these minimal models, the period of the oscillations significantly changes with the rate of degradation of the clock protein. However, depending on the model considered, the period increases, decreases or passes through a maximum as a function of the protein degradation rate. We clarify the bases for these markedly different results by bringing to light the roles of (i) protein phosphorylation, which is required for protein degradation, and (ii) the velocity and degree of saturation of mRNA and protein degradation. Changes in the parameter values of the more complex of the minimal models can produce the period profiles observed in the other two models. The analysis allows us to reconcile the contradictory predictions for the dependence of the period on the clock protein degradation rate in three minimal models used to describe circadian rhythms.

scholarly journals Rates of protein turnover in vivo and in vitro in ventricular muscle of hearts from fed and starved rats

1984 ◽  
Vol 222 (2) ◽  
pp. 395-400 ◽  
Author(s):  
V R Preedy ◽  
D M Smith ◽  
N F Kearney ◽  
P H Sugden
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Protein Turnover ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Ventricular Muscle ◽  
Degradation Rates ◽  
Perfused Hearts

Starvation of 300 g rats for 3 days decreased ventricular-muscle total protein content and total RNA content by 15 and 22% respectively. Loss of body weight was about 15%. In glucose-perfused working rat hearts in vitro, 3 days of starvation inhibited rates of protein synthesis in ventricles by about 40-50% compared with fed controls. Although the RNA/protein ratio was decreased by about 10%, the major effect of starvation was to decrease the efficiency of protein synthesis (rate of protein synthesis relative to RNA). Insulin stimulated protein synthesis in ventricles of perfused hearts from fed rats by increasing the efficiency of protein synthesis. In vivo, protein-synthesis rates and efficiencies in ventricles from 3-day-starved rats were decreased by about 40% compared with fed controls. Protein-synthesis rates and efficiencies in ventricles from fed rats in vivo were similar to values in vitro when insulin was present in perfusates. In vivo, starvation increased the rate of protein degradation, but decreased it in the glucose-perfused heart in vitro. This contradiction can be rationalized when the effects of insulin are considered. Rates of protein degradation are similar in hearts of fed animals in vivo and in glucose/insulin-perfused hearts. Degradation rates are similar in hearts of starved animals in vivo and in hearts perfused with glucose alone. We conclude that the rates of protein turnover in the anterogradely perfused rat heart in vitro closely approximate to the rates in vivo in absolute terms, and that the effects of starvation in vivo are mirrored in vitro.

scholarly journals PAQR9 Modulates BAG6-mediated protein quality control of mislocalized membrane proteins

2020 ◽  
Vol 477 (2) ◽  
pp. 477-489
Author(s):  
Xue You ◽  
Yijun Lin ◽  
Yongfan Hou ◽  
Lijiao Xu ◽  
Qianqian Cao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Membrane Proteins ◽  
Protein Degradation ◽  
Degradation Rate ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Dependent Manner ◽  
Cellular Homeostasis ◽  
Protein Degradation Rate

Protein quality control is crucial for maintaining cellular homeostasis and its dysfunction is closely linked to human diseases. The post-translational protein quality control machinery mainly composed of BCL-2-associated athanogene 6 (BAG6) is responsible for triage of mislocalized membrane proteins (MLPs). However, it is unknown how the BAG6-mediated degradation of MLPs is regulated. We report here that PAQR9, a member of the Progesterone and AdipoQ receptor (PAQR) family, is able to modulate BAG6-mediated triage of MLPs. Analysis with mass spectrometry identified that BAG6 is one of the major proteins interacting with PAQR9 and such interaction is confirmed by co-immunoprecipitation and co-localization assays. The protein degradation rate of representative MLPs is accelerated by PAQR9 knockdown. Consistently, the polyubiquitination of MLPs is enhanced by PAQR9 knockdown. PAQR9 binds to the DUF3538 domain within the proline-rich stretch of BAG6. PAQR9 reduces the binding of MLPs to BAG6 in a DUF3538 domain-dependent manner. Taken together, our results indicate that PAQR9 plays a role in the regulation of protein quality control of MLPs via affecting the interaction of BAG6 with membrane proteins.

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