Question

Importin A is critical for transport of nuclear protein B from the cytoplasm to the nucleus. If importin A was mutated that it could no longer bind protein B, which cellular compartment would I find protein B in?

Answer 1

In a normal pathway of the nuclear protein B it is transported from the cytoplasm to the nucleus through the importin A. If importin A is mutated and this transport is not possible as protein B is no longer able to bind to the importin A, then the protein B will remain in the cytoplasm. For any protein that remains in the cytoplasm is targeted for destruction after sometime by the autophagy or endosome mediated lysosomal degradation or ubiquitination. All the process leads to the transport of this protein B ultimately to the lysosome for protein degradation and hence the remnants of this protein B can be found in the lysosomes as it is directed to the lysosome.

Hence one can find this protein B in the lysosome.

If you have any query kindly comment before giving thumbs up. Thank you.