Calcium ions shuttle into and out of the cytosol — transported across membranes by channels, exchangers and pumps that regulate flux across the ER, mitochondrial and plasma membranes.

The transporters associated with antigen processing (TAPs) allow antigenic peptides that have been generated in the cytosol to be transported into the lumen of the endoplasmic reticulum (ER ...

Cellular transfer RNAs (tRNAs) are synthesized in the nucleus and can be modified there or in the cytosol to create ... into the endoplasmic reticulum (ER) lumen. Once in the ER lumen, carboxamide ...