What is the effect of the presence of uORFs in eukaryotic mRNAs?Single choice
A
An increase in abundance of small peptides in the cell.
B
Reduced translation initiation at the downstream AUG.
C
Activation of an amino acid starvation response.
D
Inhibition of eIF4F recognition at the 5’cap.
Log in for full answers
We've collected over 50,000 authentic original questions and detailed explanations from around the globe. Log in now and get instant access to the answers!
Similar Questions
Modifications are made to the rpoH gene such that its mRNA loses all secondary structure, but none of the codons for RpoH change. This would cause
Iron is an essential nutrient that is acquired by organisms from the environment. When intracellular levels of iron are relatively high, living cells synthesize an iron-storage protein called ferritin. The induction of ferritin synthesis by iron was investigated in rats. Figure 1 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and actinomycin D, a drug that inhibits transcription. Figure 2 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and cycloheximide, a drug that inhibits translation. The horizontal axes are labeled Treatment, and the vertical axes are labeled Relative Protein Level. Five tick marks appear on the vertical axis, from bottom to top, the first tick mark is labeled zero, the third tick mark is labeled one point zero, and the fifth tick mark is labeled two point zero. The graph on the left is labeled Figure one. Ferritin Protein Levels. Four vertical bars appear along the horizontal axis, and the presence or absence of Iron and Actinomycin D is indicated above each bar. The data in the graph, from left to right, are as follows: Bar 1: Absence of Iron; Absence of Actinomycin D; Relative Protein Level one point zero. Bar 2: Presence of Iron; Absence of Actinomycin D; Relative Protein Level two point two. Bar 3: Absence of Iron; Presence of Actinomycin D; Relative Protein Level zero point nine. Bar 4: Presence of Iron; Presence of Actinomycin D; Relative Protein Level two point zero. The graph on the right is labeled Figure 2. Ferritin Protein Levels. Four vertical bars appear along the horizontal axis, and the presence or absence of Iron and Cycloheximide is indicated above each bar. The data in the graph, from left to right, are as follows: Bar 1: Absence of Iron; Absence of Cycloheximide; Relative Protein Level one point zero. Bar 2: Presence of Iron; Absence of Cycloheximide; Relative Protein Level two point five. Bar 3: Absence of Iron; Presence of Cycloheximide; Relative Protein Level zero point nine. Bar 4: Presence of Iron; Presence of Cycloheximide; Relative Protein Level zero point nine. The gene sequences responsible for the iron mediated changes in ferritin protein levels are highly conserved and are called iron response elements (IREs). IREs have been observed in a number of genes involved in iron transport and metabolism. The IRE sequences found in the ferritin gene are found in all multicellular organisms, whereas other non-ferritin IRE sequences are found only in certain vertebrate organisms. Which of the following is the best explanation for the observations?
The first diagram below shows the levels of mRNA from two different genes (bicoid and caudal) at different positions along the anterior-posterior axis of a Drosophila egg immediately before fertilization. The second diagram shows the levels of the two corresponding proteins along the anterior-posterior axis shortly after fertilization. Which of the following conclusions is best supported by the data?
Iron is an essential nutrient that is acquired by organisms from the environment. When intracellular levels of iron are relatively high, living cells synthesize an iron-storage protein called ferritin. The induction of ferritin synthesis by iron was investigated in rats. Figure 1 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and actinomycin D, a drug that inhibits transcription. Figure 2 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and cycloheximide, a drug that inhibits translation. The data can best be used to support which of the following claims about the mechanism for regulating ferritin gene expression?
More Practical Tools for Students Powered by AI Study Helper
Making Your Study Simpler
Join us and instantly unlock extensive past papers & exclusive solutions to get a head start on your studies!