You are studying an individual with very low levels of insulin in her blood.Further analysis indicates that cells of her pancreas are producing normal levels of this protein, but it is accumulating in the cytoplasm rather than being secreted from the cells.Which hypothesis makes the most sense to explain this observation?
A)A small deletion has removed the nucleotides that code for the signal sequence at the amino terminus of the protein.
B)A missense mutation has caused premature termination during translation of this protein.
C)A chromosomal segment that includes the gene for insulin has been inverted.
D)A two-base deletion near the middle of the gene has altered the reading frame during translation of the protein.

Question

Quizplus · Accepted Answer

The signal sequence is crucial for directing the protein to the secretory pathway. Without it, the protein would not be properly transported out of the cell, leading to accumulation in the cytoplasm.

You Are Studying an Individual with Very Low Levels of Insulin