BIOL 2020 Lecture Notes - Lecture 6: Nuclear Pore, Nuclear Membrane, Arginine
13 Apr 2018
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*dna storage, replication and transcription take place in the nucleolus. *the nuclear membrane is a bilayer membrane (inner and outer nuclear lamina) and contains many nuclear pores. *as shown in the picture the pores are folded in an octagon-like shape (8-fold symmetry). In the transporter, there is a structure called the central transporter (or fg nucleoporins). It"s a highly disorganized, hydrophobic barrier that block diffusion. The nuclear localization signals (nlss) are: lysine = k, arginine = r, and proline (p). Importins (transporter receptors) are also part of protein nuclear import. *recall that gtpase activity turns gtp to gdp by hydrolysis. Proteins work with gtp but stop working as soon as it turned to gdp. *this occurs by guanine-nucleotide exchanges factors (gef) & gtpase activating. Gef = removes gdp to be exchanged to gtp. Ran enters as ran-gdp, with the help of rrc1 (gef), it converts to ran-gtp. Ran-gtp takes beta-importin out of the nucleus.
