Quality control chaperones

Protein Trafficking and Quality Control. Table 1 Examples of diseases associated with folding-defective, mutant proteins, and pharmacological chaperones used to correct misfolding in vitro... 

Neither chemical nor pharmacological chaperones lead to wild-type expression levels of the mutant proteins at the cell surface. Alternative or additional strategies are needed to improve the intracellular transport of the mutant proteins. In the future, dtugs may also be developed that influence those components of the quality control system that are involed in the retention of misfolded proteins. 

M. R. Protein quality control Triage by chaperones and proteases. Genes e[ Development 1997, 11, 815-823. 

SERCA pumps sequester Ca2+ in the ER lumen By maintaining appropriate Ca2+ concentrations in the ER lumen, SERCA pumps also play an essential role in protein synthesis, folding and transport of membrane and secreted proteins. This involves in particular chaperone-dependent processing and post-translational modifications which require a unique calcium rich environment. Chaperone molecules such as calreticulin and calnexin are involved in the quality control pathway in the ER (Berridge, 2002 Ellgaard and Helenius, 2003 Michalak et al., 2002). 

Calnexin and its soluble homologous calreticulin belong to the family of lectinlike chaperones. Their task is to interact with the partially trimmed monoglycosy-lated N-linked oligosaccharides and therefore contribute to an important part of the maturation and quality control mechanisms of glycoproteins [72]. The expression... 

BiP Chaperone Translocation folding, quality control bipA... 

In the past 15 years, the understanding of the mechanisms regulating protein productive folding in the lumen of the ER has considerably increased. Indeed, besides the growing number of chaperones or post-translational modification enzymes acting on newly synthesized proteins prior to their export, several specific mechanisms have been described. Amongst them, the hypothesis of a quality control system, verifying... 

Bukau, B., Weissman, J. and Horwich, A. (2006) Molecular chaperones and protein quality control. Cell 125, 443-451. 

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