MBB 222 Lecture Notes - Lecture 33: Signal Peptide, Nuclear Pore, Prokaryote
20 Dec 2018
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Document Summary
There are large differences between the eukaryotic and prokaryotic ribosome. This makes protein synthesis a good target for drugs. Many antibiotics target the bacterial ribosome or translation machinery. The nuclear pore complex regulates what can leave and enter the nucleus. Nuclear import and nuclear export rely on a g-protein called ran. Rangtp can leave the nucleus and rangdp can go back in to the nucleus. In the nucleus a gef gets ran re-loaded with gtp. Ran carries importins which bring things into the nucleus and exportins which carry things out of the nucleus. Exportins and importins recognize a signal peptide proteins that are needed in one place or another have this signal. The n-terminal region of many eukaryotic proteins is a signal peptide . Proteins destined for membranes or export are often translated into the rough er. When the signal is cleaved off, it triggers the g-proteins an opens the channel.
