Proteins involved in the process of transporting molecules in and out the cell nucleus. Included here are: NUCLEOPORINS, which are membrane proteins that form the NUCLEAR PORE COMPLEX; KARYOPHERINS, which carry molecules through the nuclear pore complex; and proteins that play a direct role in the transport of karyopherin complexes through the nuclear pore complex.

Synonyms: Nucleocytoplasmic Transport Proteins, 0, Transport Proteins, Nucleocytoplasmic