endoplasmic reticulum (ER)

Function: - the ER is the site of translation, folding, post-translational modificati (glycosylation, disulfide bond formation), & transport of proteins destined to integrate into the plasma membrane or enter the secretory pathway of secreted proteins - the GOLGI receives nascent polypeptides from the ER destined for the secretory pathway - ransfer of membranes from the endoplasmic reticulum to the Golgi occurs via 50-70 nm transition vesicles which derive from part-rough, part-smooth transitional elements of the endoplasmic reticulum (t-ER) - vesicle budding from the t-ER is an ATP-dependent process - ER is the main site of fatty acid & cholesterol biosynthesis - the signal recognition sequence (SRS) targets translation products to the rough endoplasmic reticulum (ER) - the KDEL motif retains proteins within the lumen of the ER via the KDEL receptor Structure: - the ER consists of a continuous sheet of highly folded membranes, extending from the outer nuclear membrane

Related

endoplasmic reticulum (GO:0005783) KDEL motif (endoplasmic retention consensus sequence) signal recognition sequence (SRS)

General

organelle intracellular membrane

References

Novelli G & D'Apice MR, Trends in Mol Med 9(9):370, 2003