BIO 3153 Lecture Notes - Lecture 12: Signal Recognition Particle, Calnexin, Transferase

• School: University of Ottawa
• Department: Biology
• Course: BIO 3153
• Professor: Michael Jonz

Document Summary

Proteins carry messages that get them to their destination. It"s (cid:374)ot a (cid:373)oto(cid:396) that d(cid:396)i(cid:448)e the(cid:373) so(cid:373)e(cid:449)he(cid:396)e, the p(cid:396)otei(cid:374) has a (cid:271)i(cid:374)di(cid:374)g affi(cid:374)it(cid:455) fo(cid:396) a spe(cid:272)ifi(cid:272) target. Eventually, the protein will bump into that target and stay attached to it. Er is very important in protein translocation folding and sending proteins off. Pi(cid:272)tu(cid:396)e (cid:894)sem(cid:895) sho(cid:449)s the (cid:396)ough er due to the (cid:396)i(cid:271)oso(cid:373)es atta(cid:272)hed o(cid:374) it. Movement of proteins between compartments: transmembrane transport is uni-directional. Some proteins can be removed from the er for ubiquitination. Protein sorting to the er: tem shows the er with the ribosomes and the second picture shows polyribosomes. Very similar to the plasma membrane because the er produces vesicles that pinch away and carry proteins to the plasma membrane. Transmembrane proteins are stabilized in the membrane and form the mosaic part of the fluid mosaic model of the plasma membrane. They must have some hydrophobic components as the inside of the membrane is hydrophobic.