It consists of two concentric membranes perforated by nuclear pores, large protein complexes that form aqueous channels to regulate the flow of macromolecules between the nucleus and the cytoplasm.
These complexes are composed of at least 100 different polypeptide subunits, many of which belong to the nucleoporin family.
This protein, which localizes to both sides of the nuclear pore complex at interphase, remains associated with the complex during mitosis and is targeted at early stages to the reforming nuclear envelope.
This protein also localizes to kinetochores of mitotic cells.
This article on a gene on human chromosome 1 is a stub.