BIOMG 1350 Lecture Notes - Lecture 10: Protease, Transmembrane Protein, Nuclear Localization Sequence

• School: Cornell University
• Department: Molecular Biology and Genetics
• Course: BIOMG 1350
• Professor: Discussion

Document Summary

Signal sequences are necessary and sufficient to direct a protein to its destination. Large proteins can fit through the nuclear pores. Nuclear lamina: intermediate proteins that provide nuclear envelope rigidity. Nuclear pore complexes: 8 fold star shape. Material in the middle as well, not an empty hole. Long fibrous things that stick into cytosol and nucleus (nuclear fibrils) Small molecule can simply pass through by diffusion. Prospective nucelar protein (cargo) contains nuclear localization signal. Nuclear import receptor attaches to the localization signal. Chemical properties allows it to go through the gel-like nuclear fibrils. Nuclear protein is delivered inside the nucleus. Too keep concentration high in the nucleus: ran-gtp. Ran-gtp binds to the nuclear import receptor inside the nucleus. Brings the receptor back to the outside of the cytosol. Ran-gtp is converted to ran-gdp, where it falls off. Import receptor can now bind to another nuclear protein and transport it inside the nuclear.