Final Activity Report Summary - NPC ASSEMBLY (The Nuclear Pore Complex: Assembly Required)
To gain a better understanding of this process, we set out to molecularly define early steps in nuclear pore assembly, beginning with chromatin binding. The order of recruitment of the first few building blocks, including two key integral pore-membrane proteins, was established. We find that most of the soluble nuclear pore subunits are added only after the recruitment of these key membrane components.
These findings strongly support one of the two conflicting mechanistic models that have been suggested thus far to explain NPC assembly. In addition, we have isolated native soluble nuclear pore subunits from egg extracts and we continued to investigate the regulatory role of the prototypic import receptor, importin, in NPC assembly. Overall, our results provide a detailed view of the early stages of NPC assembly, as well as the basis for mapping the exact molecular interfaces that determine this process.