Question

Which of these statements best describes how a nucleus-bound protein gets into the nucleus?

a. It freely diffuses across the nuclear pore into the nucleus
b. It binds the nuclear envelope and completes the translation of its mRNA, with the new protein being fed into the nuclear lamina
c. It binds the RER membrane, completes the translation of its mRNA, and then is exported to the nucleus in a vesicle.
d. It binds the nuclear transport receptor, which guides it through the nuclear pore.

Answer 1

The correct description of how a nucleus-bound protein enters the nucleus is through binding to a nuclear transport receptor, which then guides it through the nuclear pore in an energy-dependent process. Therefore, the correct option is D.

Step-by-step explanation:

The statement that best describes how a nucleus-bound protein gets into the nucleus is: It binds the nuclear transport receptor, which guides it through the nuclear pore. As the protein approaches a nuclear pore complex, it interacts with nuclear pore fibrils and the nuclear transport receptor. This facilitates the opening of the pore, and the nuclear transport receptor guides the protein complex across the double membrane of the nuclear envelope. The process of moving the protein into the nucleus against a concentration gradient is an active transport that relies on ATP hydrolysis as the protein enters the nucleus.