FGnucleoporines

FGnucleoporins are a specialized class of proteins found within the nuclear pore complex (NPC) of eukaryotic cells. The NPC is a large protein structure that spans the nuclear envelope, regulating the transport of molecules between the nucleus and the cytoplasm. FGnucleoporins are characterized by the presence of multiple phenylalanine-glycine (FG) repeats within their amino acid sequences. These FG repeats are crucial for the function of the NPC.

The FG-rich domains of these proteins form a mesh-like barrier within the central channel of the NPC. This barrier is largely impermeable to large molecules but can be dynamically modulated to allow or restrict the passage of specific cargoes. The FG repeats are thought to interact with transport receptors, such as importins and exportins, which are responsible for actively moving proteins and RNA across the nuclear envelope. These interactions are mediated by the hydrophobic nature of the FG repeats and their ability to form transient, disordered structures.

The precise arrangement and interactions of FGnucleoporins within the NPC create a selective barrier that ensures the fidelity of nuclear transport. Different FGnucleoporins are localized to specific regions of the NPC, contributing to the overall architecture and function of the complex. Mutations or alterations in FGnucleoporins can lead to disrupted nuclear transport, which has been implicated in various cellular processes and diseases. Research into FGnucleoporins continues to unravel the intricate mechanisms governing the exchange of genetic material and regulatory molecules between the nucleus and the cytoplasm.