Imagine that you have engineered a set of genes, each encoding a protein with a pair of conflicting signal sequences that specify different compartments. If the genes were expressed in a cell, predict which signal would win out for the following combinations. Explain your reasoning.
A) Signals for import into nucleus and import into ER
B) Signals for import into peroxisomes and import into ER
C) Signals for import into mitochondria and retention in ER
D) Signals for import into nucleus and export from nucleus