Protein sorting encoding

Figure 46-1. Diagrammatic representation of the two branches of protein sorting occurring by synthesis on (1) cytosolic and (2) membrane-bound polyribosomes. The mitochondrial proteins listed are encoded by nuclear genes. Some of the signals used in further sorting of these proteins are listed in Table 46-4. (ER, endoplasmic reticulum GA, Golgi apparatus.)...

These studies have shown that despite some variations, the same basic mechanisms govern protein sorting to all the various Intracellular organelles. We now know, for instance, that the Information to target a protein to a particular organelle destination Is encoded within the amino acid sequence of the protein Itself, usually within sequences of... 

A number of disorders have been shown to be due to mutations in genes encoding proteins involved in various aspects of protein traffic and sorting. 

Most of the mitochondrial proteins are nuclear encoded and thus must be targeted into mitochondria and sorted into some of their components after their synthesis at the cytosol. Because mitochondria have two membranes, there are four localization sites the matrix, the inner membrane, the intermembrane space, and the outer membrane (Fig. 6). Although there has been considerable progress in our understanding of these processes, some questions still remain. Moreover, the total picture is rather complicated and contains many exceptions. A simplified view is presented here based mainly on the view of Pfanner and Mihara (Mihara and Omura, 1996 Pfanner et al., 1997 Pfanner, 1998). There are also a number of other excellent reviews on this subject (Schatz, 1996 Stuart and Neupert, 1996 Neupert, 1997 Roise, 1997). 

Bailey RC, et al. DNA-encoded antibody libraries a unified platform for multiplexed cell sorting and detection of genes and proteins. J Am. Chem. Soc. 2007 129 1959-1967. 

Kohrer, K, and Emr, S. D. (1993). The yeast VPS17 gene encodes a membrane-associated protein required for the sorting of soluble vacuolar hydrolases./. Biol. Chem. 268,559-569. 

A small number of Individuals who exhibit the usual symptoms associated with familial hypercholesterolemia produce normal LDL receptors. In these individuals, the gene encoding the AP2 subunit protein that binds the NPXY sorting signal is defective. As a result, LDL receptors are not incorporated into clathrln/AP2 vesicles and endocytosis of LDL particles is compromised. Analysis of patients with this genetic disorder highlights the importance of adapter proteins in protein trafficking mediated by clathrin vesicles. I... 

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