To better understand the effects of the mutations from Question 4, you perform immunofluorescence analysis. You are lucky that your lab has a good antibody (raised in mouse) to cytosolic domain of integrin alpha 6, you also have antibody (raised in rabbit) to the ectoplasmic domain of integrin alpha 6. In wt cells, you observe a signal at the plasma membrane with both antibodies. In the mutant, in contrast, both antibodies produce a cytosolic staining
Which of the following statements best explains the effects of this mutation on the cell?
A. The mutant protein is transported to the plasma membrane, but you forgot to permeabilize the cell during your antibody staining protocol.
B. The mutant protein was not recognized by SRP for translocation into the ER
C. The mutant protein is translocated into the ER but has to undergo numerous rounds of quality control.
D. This mutation affects the localization of integrin beta 2, with which integrin alpha6 normally forms a complex.
E. The mutant integrin alpha 6 has sufficient sequence information for its direct targeting to the plasma membrane