Question

The nuclear pore complex forms a large pore with a gel-like barrier of proteins with short, repetitive domains called FG domains due to the presence of phenylalanine and glycine. How do these repeat domains contribute to the gel-like barrier? Generally, how do nuclear import receptors disrupt and traverse this barrier? (This is just focusing on the nuclear import receptors and the NPC proteins of the pore.)

Answer 1

ANSWER :-

1. The Nuclear Import Receptor is a receptor complex which is involved in the transport or more specifically a selective transport of certain components between the nucleus and the cytoplasm.
2. This receptor is associated with the Nuclear Pore complex composed of specific proteins which are called as the Nucleoporin channels which are responsible for maintaining the function of the channel.
3. These protein complex is composed of certain proteins in an unfolded state namely called as the above mentioned FG domain that is rich in the amino acids namely Phenylalanine and Glycine as denoted by the alphabets which is responsible for formation of a hydrophobic (water repelling) structure in the Nuclear pore complex which is essential for mediated the transport.
4. This complex is basically aligned in different forms providing a framework for the passage and this is supported by the presence of a hydrophilic zone that forms the supporting unit.
5. The repetitive domains are present in many numbers thereby aggregating with the other domains to forma hydrophobic arrangement in the form of a layer that is associated with selective transport by which certain molecules which are not reactive gets trapped into this layer and are refluxed into the cytoplasmic part whereas on the other hand certain other proteins complexes and nuclear cargo which are unfavorable to pass through this complex are being allowed to pass through and this indicates a role of modification in this layer made up of hydrophobic domains which in turn interacts with these protein complexes to mediate the shift in the membrane properties to mediate nuclear transport.