Which of the following BEST describes the transport of nuclear proteins across the nuclear membrane?
A) Simple diffusion
B) An N-terminal targeting sequence that is cleaved during transport
C) A targeting sequence that interacts with a carrier protein
D) Vesicular transport followed by delivery via fusion with the nuclear membrane
E) Co-translational transport using ribosomes attached to the membrane

Question

Quizplus · Accepted Answer

Nuclear proteins contain a targeting sequence or a nuclear localization sequence (NLS) that interacts with a carrier protein called importin. This complex moves towards the nuclear pore complex inside the nuclear envelope, where the NLS binds to the nuclear pore complex, and the protein enters the nucleoplasm through facilitated diffusion. Once inside, the protein may interact with other molecules such as transcription factors, DNA, and RNA.

Which of the Following BEST Describes the Transport of Nuclear