The
nucleoporins are a family of proteins which are the constituent building blocks of the
nuclear pore complex (NPC). The
nuclear pore complex is a massive structure that extends across the
nuclear envelope, forming a gateway that regulates the flow of
macromolecules between the
cell nucleus and the
cytoplasm. Nuclear pores in turn allow the transport of water-soluble molecules across the
nuclear envelope. Nucleoporins, a family of around 30 proteins, are the main components of the
nuclear pore complex in eukaryotic cells.
Nucleoporin 62 is the most abundant member of this family. Nucleoporins are able to transport molecules across the nuclear envelope at a very high rate. A single NPC is able to transport 60,000 protein molecules across the nuclear envelope every minute.