Endoplasmic reticulum lumen

Ghosal, D., Shappell, N.W., Keenan, T.W. 1994. Endoplasmic reticulum lumenal proteins of rat mammary gland. Potential involvement in lipid droplet assembly during lactation. Biochim. 

Lieviemont, f., Rizzuto, R., Hendershot, L., and Meldolesi, J. (1997). BiP, a mapr chaperone protein of the endoplasmic reticulum lumen, plays a direct and important role in the storage of the rapidly eKchanging pool of Ca, )- Bwf. Cftem. 272,30S73-30B79. 

Endoplasmic reticulum (lumen) N-terminus Yes Core of 6-12 hydrophobic amino acids, often preceded by one or more basic amino acids (Arg, Lys)... 

CH2SH + 1/2 O2 -CH2-S-S-CH2 + H2O This reaction requires an oxidative environment, and such disulfide bridges are usually not found in intracellular proteins, which spend their lifetime in an essentially reductive environment. Disulfide bridges do, however, occur quite frequently among extracellular proteins that are secreted from cells, and in eucaryotes, formation of these bridges occurs within the lumen of the endoplasmic reticulum, the first compartment of the secretory pathway. 

Collagen chains are synthesized as longer precursors, called procollagens, with globular extensions—propeptides of about 200 residues—at both ends. These procollagen polypeptide chains are transported into the lumen of the rough endoplasmic reticulum where they undergo hydroxylation and other chemical modifications before they are assembled into triple chain molecules. The terminal propeptides are essential for proper formation of triple... 

After mRNA splicing, the tropoelastin mRNA is translated at the surface of the rough endoplasmic reticulum (RER) in a variety of cells smooth muscle cells, endothelial and microvascular cells, chondrocytes and fibroblasts. The approximately 70 kDa precursor protein (depending on isoform) is synthesized with an N-terminal 26-amino-acid signal peptide. This nascent polypeptide chain is transported into the lumen of the RER, where the signal peptide is removed cotranslationally [9]. 

Found in various cellular compartments such as cytosol, mitochondria, and the lumen of the endoplasmic reticulum... 

The coupling of solute transport in the GI lumen with solute lumenal metabolism (homogeneous reaction) and membrane metabolism (heterogeneous reaction) has been discussed by Sinko et al. [54] and is more generally treated in Cussler s text [55], At the cellular level, solute metabolism can occur at the mucosal membrane, in the enterocyte cytosol, and in the endoplasmic reticulum (or microsomal compartment). For peptide drugs, the extent of hydrolysis by lumenal and membrane-bound peptidases reduces drug availability for intestinal absorption [56], Preferential hydrolysis (metabolic specificity) has been targeted for reconversion... 

FIGURE 1-12 A protoplasmic astrocyte abuts a blood vessel (lumen at I) in rat cerebral cortex. The nucleus shows a rim of denser chromatin, and the cytoplasm contains many organelles, including Golgi and rough endoplasmic reticulum, x 10,000. Inset (top left) Detail of perinuclear cytoplasm showing filaments. X44,000. 

Passage through the Golgi apparatus is obligatory for most proteins destined for fast transport. In all cell types, secretory and integral membrane proteins are synthesized on polysomes bound to the endoplasmic reticulum. Secretory proteins enter the lumen of the reticulum, whereas membrane proteins become oriented within the... 

McDaniel SS, Platoshyn O, Wang J et al 2001 Capacitative Ca2+ entry in agonist-induced pulmonary vasoconstriction. Am J Physiol 280 L870-L880 Meldolesi T, Pozzan T 1998 The endoplasmic reticulum Ca2+ store a view from the lumen. Trends Biochem Sci 23 10-14... 

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