In immunofluorescence studies you always see the small G-protein Ras in a specific region of the cell and,given its protein sequence along with many other proteins localized to this area,you hypothesize that their C-terminal Cys-Ala-Ala-X (X can be any amino acid)motifs may be responsible for targeting these proteins to this subcellular region.To test this hypothesis,you genetically engineer the sequence encoding this motif onto a cDNA encoding green fluorescent protein.When immunofluorescence is used,where specifically would you expect to see GFP localized in the cell?
A)in the nucleus
B)in the cytoplasm
C)in the Golgi
D)at the plasma membrane

Question

Quizplus · Accepted Answer

Since the C-terminal Cys-Ala-Ala-X motifs are responsible for targeting proteins to the plasma membrane, if GFP has been engineered with this motif, it is expected to be localized at the plasma membrane.

In Immunofluorescence Studies You Always See the Small G-Protein Ras