The amino-terminal domain of the lamin B receptor is a nuclear envelope targeting signal

In summary, the amino-terminal domain of the inner nuclear membrane LBR can function as a nuclear envelope targeting signal and can direct a type II integral membrane protein synthesized on the ER to the nuclear envelope, likely the inner nuclear membrane. The targeting polypeptide may be accumulated in the nucleus either by active transport used by proteins that contain nucleoplasmin-like bipartite NLS's or by diffusion and ligand binding. Future experiments examining the details of lamin B binding, chromatin binding, and in vitro transport of the LBR amino-terminal domain will help further elucidate the mechanism of how this polypeptide functions as a nuclear envelope targeting signal.