Question

Map out the pathway a protein will take when it is destined for the nucleus.

a) Synthesis in the cytoplasm, transport through nuclear pores
b) Synthesis in the nucleus, release into the cytoplasm
c) Synthesis on the endoplasmic reticulum, transport via vesicles
d) Direct diffusion across the nuclear membrane

Answer 1

Proteins destined for the nucleus are synthesized in the cytoplasm and carry signals that guide them through the nuclear pores into the nucleus.

Step-by-step explanation:

The pathway a protein will take when it is destined for the nucleus begins with its synthesis in the cytoplasm. Proteins synthesized in the cytoplasm that are targeted for the nucleus, mitochondria, or chloroplasts contain oligopeptide signals that direct them to their appropriate destinations. These signals ensure that the protein is correctly transported through the nuclear pores into the nucleus. This process is vital because DNA, which is housed in the nucleus, is used to produce RNA. The RNA then exits the nucleus and enters the cytoplasm where ribosomes translate it into proteins. It's these ribosomal proteins that, if signaled for nuclear localization, will subsequently find their way through the nuclear pores into the nucleus.