A nuclear protein is a protein found in the cell nucleus.[1] Proteins are transported inside the nucleus with the help of the nuclear pore complex, which acts a barrier between cytoplasm and nuclear membrane. The import and export of proteins through the nuclear pore complex plays a fundamental role in gene regulation and other biological functions.[2][3]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Diagram_of_nuclear_uptake_of_protein.jpg/220px-Diagram_of_nuclear_uptake_of_protein.jpg)