China 
Africa 
Explore chapters and articles related to this topic
Use of Recombinant DNA Technology for Engineering Mammalian Cells to Produce Proteins
Published in Anthony S. Lubiniecki, Large-Scale Mammalian Cell Culture Technology, 2018
Since a naturally occurring cell line producing factor VIII has never been obtained, little is known of the intracellular processing events required to generate the mature forms of factor VIII found in plasma. Initial [35S] methionine pulse-labeling and chase experiments demonstrated that only a fraction of the factor VIII which is synthesized is ever secreted from CHO cells. The factor VIII that is not secreted is observed in the ER in a complex with the immunoglobulin-binding protein or BiP (196). BiP is identical to the glucose-regulated protein of 78 kDa (GRP78) and is homologous to members of the hsp 70 protein family (217). Although the function of BiP remains unknown, it binds proteins to a greater degree when normal protein folding or N-linked glycosylation is blocked and may prevent thrir transport and secretion (194, 195, 217). It is not known whether BiP acts to detect and remove improperly folded proteins that are secretion-incompetent or whether it actually facilitates protein folding and/or transit through the ER (197).
Cell Biology for Bioprocessing
Published in Wei-Shou Hu, Cell Culture Bioprocess Engineering, 2020
Folding of the polypeptide starts immediately upon translocation into the ER lumen. The signal peptide on the elongating polypeptide in the ER lumen is cleaved upon entry into the ER. A class of ER chaperones and other proteins that facilitate protein folding act on the nascent protein molecules to prevent them from aggregating and to facilitate folding. Their actions require cellular energy (ATP). An important member of the ER luminal chaperones, BiP (also known as GRP78), is also a component of the translocator complex. BiP binds to hydrophobic amino acids in incompletely folded proteins to prevent them from aggregating. In addition to BiP, major ER luminal chaperones include protein disulfide isomerase (PDI), which facilitates the formation of the correct disulfide bond.
Effects of a resistance-training programme on endoplasmic reticulum unfolded protein response and mitochondrial functions in PBMCs from elderly subjects
Published in European Journal of Sport Science, 2019
Brisamar Estébanez, Osvaldo C. Moreira, Mar Almar, José A. de Paz, Javier Gonzalez-Gallego, María J. Cuevas
BiP is the chaperone that recognizes the unfolded proteins and triggers UPR activation. Our results indicate that BiP levels are not compromised in elderly subjects. In agreement with this, several studies have shown the same results in many tissues, including brain, pancreas kidney or muscle, from both humans and animal models (Baehr et al., 2016; Chalil, Jaspers, et al., 2015; Drummond et al., 2011; Gavilán et al., 2006; Naidoo et al., 2014; Ogborn et al., 2014). However, other authors have described the opposite results depending on the evaluated tissues (Chalil, Jaspers, et al., 2015; Takeda et al., 2013). Moreover, ATF6 has been considered the major transcriptional activator of BiP expression (Borsa et al., 2015) and, as in our case, the few researches that have evaluated ATF6 levels have found the same results for ATF6 as for BiP, which could explain why this protein, involved in the folding process, is not altered with age.