A mutation that results in the loss of the formation of the iron response element (IRE) in the 5′-UTR of the ferritin mRNA will be expected to have what effect?
A) decreased translation of the mRNA in the presence of high iron
B) decreased translation of the mRNA when iron is low
C) increased translation of the mRNA in the presence of high iron
D) increased translation of the mRNA when iron is low
E) reduced stability of the mRNA

Question

Quizplus · Accepted Answer

Ferritin is an iron-binding protein that prevents toxic levels of ionized iron (Fe2+) from building up in cells. When iron levels are high, the iron-response element-binding protein (IRBP) cannot bind to the IRE in the 5′-UTR of the ferritin mRNA. This allows the ferritin mRNA to be translated. Conversely, when iron levels are low, the IRBP binds to the IRE in the ferritin mRNA preventing its translation. Therefore, loss of the IRE in ferritin would result in increased translation even when iron levels are low since the IRBP would have nothing to which to bind.

A Mutation That Results in the Loss of the Formation