Rough endoplasmic reticulum is a type of endoplasmic reticulum in which the cytoplasmic, membrane-lined cavities are covered with ribosomes.
The ribosomes are attached to the outer, cytoplasmic surface of the rER by specialized protein receptors. The ribosomes may be linked along the membrane surface by a strand of messenger RNA to create a polyribosome. The ribosomes are the main reason rER takes up basophilic stains for light microscopy.
The rER functions to produce and compartmentalise proteins, lipids and other cellular constituents. Polypeptide chains are manufactured at the ribosome and then are either:
There are a number of non-ribosomal proteins in the membrane of the rER which are involved in further processing molecules e.g. post-translational glycosylation, active transport of lipid molecules across the rER membrane.
Last reviewed 01/2018