Questions about nuclear transport of proteins.....
How does the protein get to the nuclear membrane in the first place?
 | How is transport to the NPC mediated? How does the protein get from the cytosol/nucleus to the nuclear membrane? What other molecules are involved? Is the NPC the only way that proteins can get into/out of the nucleus? |
What are Nuclear Localization Signals and Nuclear Export Signals?
| What are nuclear localization signals/nuclear import signals? How do these "signal" for a protein to be imported/exported from the nucleus? What other proteins are involved? What are the different types of NES/NLS? Are they involved in different import/export pathways? How do you determine that a specific protein sequence(s) is/are an NLS/NES? What characteristics of NES/NLS allow it to mediate transport (location in the protein, specific structure, amino acid content...) How can proteins be engineered to introduce a functional NES/NLS into their structure? For what types of experiments would this be useful? Can a protein be transported if it does not have a defined NES/NLS? |
How does the protein actually get through the NPC?
| What factors determine whether a protein can cross the nuclear membrane through the NPC? How is size involved? How is the structure of the protein involved? What specific interactions mediate the transport through the pore? How do these interactions provide the specificity to determine what is transported and what is excluded? What is the structure of the NPC? How does the structure of the NPC facilitate transport? What other proteins are involved? Are other proteins absolutely necessary for transport? How are these proteins mediating the transport regulated? How do small molecules pass through the NPC? What experiments can one do/have people done to figure this out? Can proteins be blocked from crossing the nuclear membrane? |
How is transport in and out of the nucleus regulated?
| How is Ran-GTP involved in the regulation of nuclear transport? What other factors influence the nucleotide state of Ran? What other proteins are involved in this cycle? Are there factors other than Ran that regulate the transport of protein in and out of the nucleus? In addition to the "classical" nuclear transport model, what other pathways mediating nuclear transport have been elucidated? |
What is the "purpose" of nuclear transport?
| What cellular processes are regulated/influenced by nuclear transport? How can nuclear transport be manipulated to study these processes? |
Experimental strategies for studying nuclear transport
| How can one monitor the location of a protein within a cell (in vivo)? How can nuclear transport be studied in vitro? How is a nuclear import/localization signal defined? How can nuclear transport be disrupted? |