Transport and protein sorting in eukaryotic cells

This review describes fundamental cellular mechanisms involved in intracell ular transport. The ubiquitous role of transport vesicles allows similar me chanisms to participate in many different steps of intracellular transport. In each case, a different cytoplasmic coat polymerizes on the membrane of the budding vesicle, and interacts with specific signals located in the cyt oplasmic domains of membrane proteins which must be concentrated in the ves icle. The number of characterized cytoplasmic sorting signals is increasing rapidly, as well as the number of identified coats. Intracellular sorting can be perturbed by inherited mutations and can result in pathological situ ations such as cystic fibrosis or familial hypercholesterolemia. Viruses ca n also use or divert sorting mechanisms of eucaryotic cells, which are esse ntial for their efficient propagation. Therefore, deciphering the cellular machinery responsible for intracellular transport and sorting of proteins i s essential for a better understanding of many pathological situations.