Organisms Maintain Protein Fidelity And The Body ( Labbadia Et Al

The endoplasmic reticulum is specialised for protein processing and lipid biosynthesis. One of its primary functions is to regulate the ionic concentration in the cytoplasm via the movement of Ca2+, via ionic pumps and channels. It also contains enzymes responsible for the metabolising of drugs. Endoplasmic reticulum (ER) can come in two forms. As depicted in Fig. 2 Rough ER has ribosomes present as part of the membrane of the organelle, and together with these ribosomes takes polypeptides and amino acids from the cytosol and synthesises proteins destined for attachment to cell membranes. It is in the lumen of the rough ER that the proteins are folded into the specific three dimensional shapes that are so important for biochemical recognition and linking sites [6]. It is called rough because of the presence of ribosomes makes the surface of the membrane look rough, unlike smooth ER, which lacks the ribosomes so the membrane looks smooth. Rough ER is composed of a large but convoluted flattened sac. The main function of the smooth ER is the production of lipids and the metabolism of compounds (such as the breakdown of glycogen into glucose). Because of the different functions between the rough and smooth ER, different specialised cells will have different amounts of each; for example, hepatic

sHSPs are a ubiquitous class of chaperones found across all kingdoms of life. sHSP range in size from 12-42 kilo Daltons in large oligomers of 12 to >32 subunits and the structure is homologous across all species. The sHSP monomer consists of three domains: a disordered N-terminal arm, a beta-sandwich α-crystallin domain, and a flexible C-terminal extension. The N-terminal domain is the most variable region with little conservation between species. Experimental evidence also suggests N-terminal involvement in substrate binding and protection. The α-crystallin domain is the most highly conserved region and adopts a β-sandwich conformation composed of 7 to 8 anti-parallel β-strands (Basha et al, 2012). The C-terminus contains an I-X-I motif, which helps to satblizie the oligomeric form of the sHSP (Basha et al, 2012).

as well as enhancing key mitochondrial activity (such as Complex IV) (Atamna 22). Tau proteins

Arnold explains: "Rather than a cell deciding when a protein needs to be degraded, we sort of hijack the process."

DVL 1 protein is a cytoplasmic phosphoprotein produced by DVL 1 gene regulating the cell formations and a transducer particle for the developmental processes such as neuroblast specification and segmentation.1 In Wnt Signalling Pathway, the DVL 1 protein works by binding to C-terminus of frizzled receptors and transduce the wnt signal in both canonical and non-canonical pathway.2 These pathways activation lead to the accumulation of beta catenin protein in the cell which known to have important roles in proliferation and formation of the cells.2

Amino acid can be found in food we eat every day for example it can be found in meat and dairy. It is extremely common in meat such as pork,beef and chicken. It is also common in dairy products such as eggs,milk,yogurt and cheese. Both meat and dairy contain protein as amino acid is one of the key components that make up protein. Protein is made up of hundreds of small compounds, one of which is amino acids. They all attach into long chain by something called peptide bonds and all of these long chains join together and form protein which is in the foods we eat and is an essential compound in the body.

You are a frustrated student who has a big biochemistry test tomorrow, but no time to look over material because he have to work at Kroger tonight until closing because you used up all your sick days. Your annoying boss tells you there is a shipment of new milk and meat products coming in and the old, expired products must be removed. He gives you bright green stickers to stick onto the expired products that need to be removed from the shelves. As you are doing this, you start to think about your test and try to apply biochemistry to real-life situations, but to no avail. You get more frustrated and contemplate quitting your job right there. Suddenly, you think about the word ‘quit’ and realize you have to know about ubiquitin for tomorrow’s test. You remember one of ubiquitin’s many roles is to tag an unneeded protein for its destruction. Then you start realizing that labeling stickers on expired products so they can be removed in a supermarket is like ubiquitin labeling old, outdated proteins in our cells so they can be removed for the proteins still needed

Autophagy gives cells with oxidizable substrate when nutrients become deficient. It can give protection against aging and a number of pathologies such as cancer, cardiac disease, diabetes, neurodegeneration, and infections. Autophagy principally plays an adaptive character to save organisms against various pathologies, including infections, cancer, and aging, neurodegeneration, and heart disease. A number of modern studies have stressed the importance of autophagy and the ubiquitin-proteasome in the pathogenesis of muscle declining in different types of inherited muscle problems.

The integrated stress response (ISR) is characteristic of multicellular eukaryotes, and is triggered when cells experience any type of stress stimulus. Stress stimuli include misfolded proteins, oxidative damage, heat shock, and viral expression. ISR is initiated by phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α) at the Ser51 residue, which promotes stronger binding to the regulatory subcomplex of eIF2B (Starck et al., 2016). This stronger binding inhibits eIF2B from catalyzing guanine nucleotide exchange of GDP for GTP, because it cannot release from eIF2 (Weaver, 2012). Several subunits of eIF2B are involved in guanine nucleotide exchange (Kashiwagi et al., 2016). The inhibition of guanine nucleotide exchange will limit the supply of initiator methionyl transfer RNA (Met-tRNAiMet), which plays a role in initiation at AUG start codons. Therefore, during IRS, eIF2α-phosphorylation blocks global translation of protein synthesis (Starck et al., 2016).

Also in oxidative stress, inducing ATG proteins expression through PERK (Protein kinase RNA-like endoplasmic reticulum kinase) activate canonical autophagy. DUE TO the activation of these proteins autophagy begins, (and consequently or so) sustains the required energy of the cell.

Turnover mechanisms such as ubiquitination must be carefully regulated, as it is very significant in metabolic regulation, and removing errors which arise during the transcription and translating process, as well as protein activation and degradation which is necessary for some signalling pathways. Proteins that are targeted for degradation use energy from ATP hydrolysis to form an isopeptide bond between the targeted protein and ubiquitin. In addition, the activated carboxyl terminal glycine of ubiquitin is covalently bonded to the ε–amino groups in multiple Lys located in the protein.

Bostanciklioglu, M. (2015). The Role of Autophagy in Stress and Cancer. Single Cell Biology, 04(02). doi:10.4172/2168-9431.1000111

The endoplasmic reticulum (ER) is an essential organelle that is a major place for the biogenesis of cellular components including proteins, lipids, and carbohydrates and internal calcium storage. ER is primarily responsible for protein translocation, protein folding and protein post modification. Proper folding of protein in the ER is accomplished with the aid of ER resident proteins or enzymes such as chaperones. Binding of chaperones to

Molecular chaperones stabilize unfolded or misfolded proteins until native conformations have been obtained to promote cell survival during and after stress conditions. They do not change or add to the folding principles encoded by a protein because polypeptide chains inherently carry within them all the information that is necessary for achieving the native state of a protein. Instead, they optimize the folding process by stabilizing folding intermediates and are involved in every aspect of proteome maintenance including de novo folding, refolding of stress-induced misfolded proteins, and targeting proteins for degradation (Hartl 2009, Hartl 2011). Chaperones, many of which are induced or upregulated only during stress conditions, work in cooperative networks when protein-aggregate concentration

Proper cell behavior is maintained using a finite pool of processing resources, such as the limited pool of enzymes required for gene transcription and protein translation1-2. Natural biological circuits are largely thought to have evolved to buffer against the effects of limited resources, but we are beginning to understand how processing machinery can form a bottleneck that is in fact leveraged as a control or signaling mechanism3-4. Proteolytic (protein degrading) pathways, in particular, have been found to form functional bottlenecks in a native E. coli network regulating the stationary phase sigma factor S (S). The protein S is degraded by the ClpXP proteolysis system (ClpXP protease and its chaperones) much faster during