| A | B |
|---|
| Nuclear pore complex | Large mulitprotein structure in the nuclear envelope that allows selective transport between nucleus and cytoplasm. |
| Nuclear localization signal (NLS) | Signal sequence or signal patch that directs proteins to the nucleus. Not cleaved off after transport into the nucleus. |
| ER signal sequence | N-terminal signal sequence of some 20 amino acids that directs proteins to the ER. |
| Signal peptidase | ER membrane protein that cleaves off the ER signal sequence. |
| Signal recognition particle (SRP) | Ribonucleoprotein that binds to a ribosome and an ER signal sequence on a partially synthesized protein. |
| SRP receptor | ER membrane protein. Binds the SRP which brings the SRP-ribosome complex to a protein translocator. |
| Sec61 complex | Protein translocator in the ER membrane. |
| ER retention signal | C-terminal signal sequence of 4 amino acids that that retains proteins in the ER. |
| BiP, calnexin, calreticulin | ER resident chaperone proteins. Calnexin and calreticulin requires calcium for their activities. |
| Glycosylphosphatidylinositol (GPI) anchor | Lipid linkage by which some proteins are bound to the plasma membrane. Formed in the ER. |
| N-linked glycosylation | Transfer of precursor oligosaccharide from dolichol to asparagine side chain in ER. Further modified in ER and Golgi. |
| O-linked glycosylation | Addition of sugars to serine and threonine side chains in Golgi. |
| Cis Golgi network (CGN) - cis, medial and trans cisternae - trans Golgi network (TGN) | Layout of the Golgi apparatus. Proteins arrive from the ER to CGN and are sent on to secretion etc. from TGN. |
| Complex oligosaccharides, high-mannose oligosaccharides | Outcomes of Golgi modification of oligosaccharides added in ER by N-linked glycosylation. |
| Vesicular transport model, cisternal maturation model | Two models of transport through the Golgi apparatus. Not mutually exclusive. |
| Constitutive resp. regulated secretory pathway. | The two secretory pathways. The first operates continously in all cells, the second in specialized secretory cells when stimulated. |
