Rough Endoplasmic Reticulum (RER)
The rough endoplasmic reticulum is an organelle in a cell that produces proteins and lipids. Ribosomes on the RER are called membrane bound and are responsible for protein production, in the pancreas and other parts of the digestive tract the ribosomes make large amounts of proteins used in digestion. There are about 13 million ribosomes on the RER in liver cells, and they are found throughout the cell but in high density around the nucleus and Golgi. Cells that specialize in lipid production tend to have more RER than those that specialize in hormone production. The RER is connected to the nuclear envelope and works closely with the golgi apparatus, in which the RER packages proteins in vesicles and the Golgi transports them throughout the cell. The rough ER, working with membrane bound ribosomes, takes polypeptides and amino acids from the cytosol and continues protein assembly. It is in the lumen of the rough ER that proteins are folded to produce the structure which will provide 'lock and key' and other recognition and linking sites. In the lumen the proteins are inspected for quality and if a problem in size shape or folding is found the protein is rejected. A type of emphysema (a lung problem) is caused by the ER quality control section continually rejecting an incorrectly folded protein. The protein, which is wrongly folded as a result of receiving an altered genetic message, is never exported from the lumen of rough ER.
Having trouble remembering what the RER is, listen to the Rough ER Song below.
Having trouble remembering what the RER is, listen to the Rough ER Song below.