Transport within the Golgi: for the Study of Glycoprotein Movement

About 30% of the proteins synthesized in cells are first transported to the endoplasmic reticulum (ER), then to the Golgi, where they are sorted to their final destination.In the ER, newly synthesized proteins are folded and undergo several types of posttranslational modifications such as the attachment of precursor oligosaccharides.In the Golgi, all glycoproteins transported from the ER receive complex post-translational modifications including glycosylation, sulfation, and phosphorylation.Transport of these proteins from the ER, via the Golgi, to their final destination is called anterograde transport, whereas the reverse is called retrograde transport.The transport of proteins within cells normally requires transport vesicles of approximately 50-90 nm in diameter.At least