BIOB11H3 Lecture Notes - Lecture 7: Nuclear Pore, Nummelan Palloseura, Nuclear Membrane
Document Summary
The nuclear pore complex (npc: the nuclear pore is not an open channel. It fills the nuclear pore (like a stopper: the nuclear pore complex: Is a very large basket shaped structure: has two rings (cytoplasmic and nucleoplasmic) which are connected by spokes. Is a central trabsport channel: has octagonal symmetry due to eightfold repetition of a number of structures, can have a number of different proteins called nucleoporins (nups) Nuclear import of proteins: a nuclear localization signal (nls) is required for the proteins to enter through the npc, classical nls is one of two stretches of positively charged amino acids. A conformational change in the nuclear pore makes it open: the receptor-cargo complex interacts with ran-gtp (ran protein bound with. At this point, the nls containing protein is inside the nucleus: ran-gtp + importin-beta moves to the cytosol via npc where gtp is hydrolyzed to gdp.
