Protein stress

Protein stress and recycling of nitrogen could also have the opposite effect, however. If less N-depleted N is excreted as inea, then there should be less overall enrichment in the nitrogen available for tissue synthesis. Moreover, if urea itself is recycled for protein synthesis under protein stress, which often occurs in herbivores, then the diet-tissue difference should be smaller than in unstressed individuals because urea has a substantially lower 8 N value than the diet. 

Effects of Protein Stress on Tissue Nitrogen Isotopes... 

Protein stress has been proposed to cause tissue nitrogen isotope emich-ment (Hare et al. 1991 Hobson and Clark 1992). Diets B and C, with 5% protein by weight, produced offspring that achieved substantially smaller adult weights, clearly demonstrating protein limitation. In many cases the... 

Our results do not support the protein stress model. However, this model may apply in cases where stress is intermittent and results in tissue loss, as observed in the study of crows (Hobson and Clark 1992). Low protein levels throughout life after weaning may have produced overall slow and reduced rate of growth rather than tissue loss. Adult rats fed protein-deficient diets after maturation show systematic losses of nitrogen from most tissues that are in proportion to their turnover rates and masses (Uezu et al. 1983). Perhaps tissue nitrogen isotope enrichment may occur under these conditions. New experiments are needed to evaluate this hypothesis. 

Imai, Y., M. Soda, and R. Takahashi, Parkin Suppresses Unfolded Protein Stress-induced Cell Death through Its E3 Ubiquitin-protein Ligase Activity. J Biol Chem, 2000, 275(46), 35661-35664. 

Kawaguchi Y, Kovacs JJ, McLaurin A, Vance JM, Ito A, Yao TP (2003) The deacetylase HDAC6 regulates aggresome formation and cell viabihty in response to misfolded protein stress. Cell 115 727-738... 

Imai, Y., Soda, M., Takahashi, R. 2000. Parkin suppresses unfolded protein stress-induced cell death through its E3 ubiquitin-protein ligase activity. J Biol Chem 275 35661-4. 

Keywords Reference material Traceability Total protein Stress indicators... 

Calderwood, S. K., and Ciocca, D. R. (2008). Heat shock proteins stress proteins with Janus-like properties in cancer. Int J Hyperthermia 24(1), 31-39. 

Ubiquitin, found in several cellular compartments (e.g., cytoplasm and the nucleus), belongs to a class of proteins referred to as stress proteins. Stress proteins, also called heat shock proteins (hsp), are so named because their syntheses are accelerated (and in some cases initiated) when cells encounter stress. (The name heat shock protein is misleading, because a variety of stressful conditions besides elevated temperature induce their synthesis.) Other stress proteins act as molecular chaperones, that is, they promote protein folding (p. 692). Heat shock proteins and molecular chaperones also play significant roles in protein transport and intermolecular interactions. 

Stress proteins (also called heat shock proteins) are meant to protect organisms against damaging environmental effects. They do this by repairing damaged proteins. Stress proteins can act as biomarkers of integrated environmental stress effects. 

Hohenblum, H., Gasser, B., Maurer, M., Borth, N., and Mattanovich, D. (2004) Effects of gene dosage, promoters, and substrates on unfolded protein stress of recombinant Pichia pastoris. Biotechnol. Bioeng., 85, 367 -375. 

Nelfinavir inhibits experimentally induced tissue degeneration and cell damage by preventing loss of the mitochondrial membrane potential and even protects mitochondria in cancer cells. However, conversely, it selectively induces a mitochondria-independent cell death mechanism in cancer cells by the so-called endoplasmic reticulum unfolded protein stress response, allowing it to act on otherwise chemoresistant cancer cells [127 ]. 

Jakobsen L.D., Jensen P.H. (2003) Parkinson s disease alpha-synuclein and parkin in protein aggregation and the reversal of unfolded protein stress. Methods Mol Biol, 232 57-66. 

Van Simaeys, D., Turek, D., Champanhac, C., Vaizer, J., Sefah, K., Zhen, J., Sutphen, R., Tan, W., 2014. Identification of ceU membrane protein stress-induced phosphoprotein 1 as a potential ovarian cancer biomarker using aptamers selected by ceU systematic evolution of ligands by exponential enrichmenL Anal. Chem. 86,4521-4527. 

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